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Sample records for au pb bi

  1. Mass Spectrometric Studies on Metai-hexafluorobenzene Anionic Comolexes(M=Ag,Au,Pd,Pt,Pb and Bi)

    Institute of Scientific and Technical Information of China (English)

    SUN Zhang; SUN Shu-tao; LIU Hong-tao; ZHU Qi-he; GAO Zhen; TANG Zi-chao

    2009-01-01

    The anionic products from the reactions between metal(M=Ag,Au,Pd,Pt,Pb and Bi) vapour produced by laser ablation and hexafluorobenzene seeded in carrier gas(Ar) were studied by means of a homemade reflectron time-of-flight mass spectrometry(RTOF-MS).Experimental results show that the dominant products were [MmC6F6]-complexes for the reactions of Ag,Au,Pd and Pt with C6F6,while the dominant products were [MmC6Fs]- complexes for the reactions of Pb and Bi with C6F6.The formation mechanisms of the products,including the adsorption of metal cluster anions on hexafluorobenzene and the C-F cleavage induced by metal cluster anions,were discussed.

  2. β -decay half-lives and β -delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N =126

    Science.gov (United States)

    Caballero-Folch, R.; Domingo-Pardo, C.; Agramunt, J.; Algora, A.; Ameil, F.; Ayyad, Y.; Benlliure, J.; Bowry, M.; Calviño, F.; Cano-Ott, D.; Cortès, G.; Davinson, T.; Dillmann, I.; Estrade, A.; Evdokimov, A.; Faestermann, T.; Farinon, F.; Galaviz, D.; García, A. R.; Geissel, H.; Gelletly, W.; Gernhäuser, R.; Gómez-Hornillos, M. B.; Guerrero, C.; Heil, M.; Hinke, C.; Knöbel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Yu. A.; Maier, L.; Marganiec, J.; Marta, M.; Martínez, T.; Montes, F.; Mukha, I.; Napoli, D. R.; Nociforo, C.; Paradela, C.; Pietri, S.; Podolyák, Zs.; Prochazka, A.; Rice, S.; Riego, A.; Rubio, B.; Schaffner, H.; Scheidenberger, Ch.; Smith, K.; Sokol, E.; Steiger, K.; Sun, B.; Taín, J. L.; Takechi, M.; Testov, D.; Weick, H.; Wilson, E.; Winfield, J. S.; Wood, R.; Woods, P. J.; Yeremin, A.

    2017-06-01

    Background: There have been measurements on roughly 230 nuclei that are β -delayed neutron emitters. They range from 8He up to 150La. Apart from 210Tl, with a branching ratio of only 0.007%, no other neutron emitter has been measured beyond A =150 . Therefore, new data are needed, particularly in the region of heavy nuclei around N =126 , in order to guide theoretical models and help understand the formation of the third r -process peak at A ˜195 . Purpose: To measure both β -decay half-lives and neutron branching ratios of several neutron-rich Au, Hg, Tl, Pb, and Bi isotopes beyond N =126 . Method: Ions of interest were produced by fragmentation of a 238U beam, selected and identified via the GSI-FRS fragment separator. A stack of segmented silicon detectors (SIMBA) was used to measure ion implants and β decays. An array of 30 3He tubes embedded in a polyethylene matrix (BELEN) was used to detect neutrons with high efficiency and selectivity. A self-triggered digital system is employed to acquire data and to enable time correlations. The latter were analyzed with an analytical model and results for the half-lives and neutron-branching ratios were derived by using the binned maximum-likelihood method. Results: Twenty new β -decay half-lives are reported for Au-206204, Hg-211208,Tl-216211,Pb-218215 , and Bi-220218, nine of them for the first time. Neutron emission probabilities are reported for Hg,211210 and Tl-216211. Conclusions: The new β -decay half-lives are in good agreement with previous measurements on nuclei in this region. The measured neutron emission probabilities are comparable to or smaller than values predicted by global models such as relativistic Hartree Bogoliubov plus the relativistic quasi-particle random phase approximation (RHB + RQRPA).

  3. Superconductivity in Ba(Pb,Bi,Sb)O 3, Ba(Pb,Bi,Te)O 3 and (Ba,La) (Pb,Bi,Tl)O 3 systems

    Science.gov (United States)

    Nagarajan, R.; Vasanthacharya, N. Y.; Gopalakrishnan, J.; Rao, C. N. R.

    1991-02-01

    It is possible to substitute Bi in the superconducting BaPb 0.75Bi 0.25O 3 by Sb or Te without destroying the superconductivity. With Sb, a continuous series of solid solutions BaPb 0.75Bi 0.25-ySb yO 3 (0 ⩽ y ⩽ 0.25) exists, while with Te, perovskite BaPb 0.75Bi 0.25-yTe yO 3 exists only upto y = 0.15. With increasing substitution by Sb or Te, T c decreases continously in both the systems. Superconductivity with a maximum T c of 8K is found in Ba 0.9La 0.1Pb 0.9-yBi yTl 0.1O 3 for y = 0.25.

  4. Bi-sulphotellurides associated with Pb - Bi - (Sb ± Ag, Cu, Fe) sulphosalts: an example from the Stan Terg deposit in Kosovo

    Science.gov (United States)

    Kołodziejczyk, Joanna; Pršek, Jaroslav; Voudouris, Panagiotis Ch.; Melfos, Vasilios

    2017-08-01

    New mineralogical and mineral-chemical data from the Stan Terg deposit, Kosovo, revealed the presence of abundant Bi-sulphotellurides associated with Bi- and Sb-sulphosalts and galena in pyrite-pyrrhotite-rich skarn-free ore bodies (ores without skarn minerals). The Bi-bearing association comprises Bi-sulphotellurides (joséite-A, joséite-B, unnamed phase A with a chemical formula close to (Bi,Pb)2(TeS)2, unnamed phase B with a chemical composition close to (Bi,Pb)2.5Te1.5S1.5), ikunolite, cosalite, Sb-lillianite, members of the kobellite series and Bi-jamesonite. Compositional trends of the Bi-sulphotellurides suggest lattice-scale incorporation of Bi-(Pb)-rich module and/or admixture with submicroscopic PbS layers in modulated structures, or complicated Bi-Te substitution. Cosalite is characterized by high Sb (max. 3.94 apfu), and low Cu and Ag (up to 0.72 apfu of Cu+Ag). Jamesonite from this mineralization has elevated Bi content, from 0.85 to 2.30 apfu. The negligible content of Au and Ag in the Bi-sulphotellurides, the low content of Ag in Bi-sulphosalts, together with the lack of Au-Ag bearing phases in the mineralization, indicate either ore deposition from fluid(s) depleted in precious metals, or physico-chemical conditions of ore formation preventing Au and Ag precipitation at the deposit site. The temperature of initial mineralization may have exceeded 400 °C as suggested by the lamellar exsolution textures observed in lillianite, which indicate breakdown textures from decomposition of high-temperature initial crystals. Non-stoichiometric phases among the Bi-sulphosalts and sulphotellurides studied at Stan Terg reflect modulated growth processes in a metasomatic environment.

  5. Anodic Synthesis and Characterization of Na-Pb-O, Na-Pb-Bi-O Crystals

    Institute of Scientific and Technical Information of China (English)

    Li Mei QIU; Fen LIU; Liang Zhong ZHAO

    2005-01-01

    Crystals of Na-Pb-O and Na-Pb-Bi-O were electrosynthesized on the anode from molten salts. The resulting crystals have a hexagonal structure, in which the base ions (Pb and Bi) are in high oxidation states. By using KOH/NaOH (atomic ratio K:Na=1:1) mixture as a flux,incorporation of K ions into the lattice is inhibited while incorporation of Bi ions is enhanced. The magnetic measurement shows that the Na-Pb-Bi-O crystals are dominated by diamagnetism.

  6. Characteristics on Bi-Pb Based Alloys Quenched from Melt

    Institute of Scientific and Technical Information of China (English)

    Rizk Mostafa Shalaby

    2009-01-01

    Three different bismuth-lead systems namely, Wood's alloy (Bi50Pb25Sn12.5Cd12.5), Newton's alloy (Bi50Pb31.2Sn18.8) and Rose's alloy (Bi50Pb28Sn22), with one used as fusible alloys were quenched from melt by melt spinning technique. Thermal analysis, structure and mechanical properties of all alloys have been studied and analyzed. From X-ray diffraction analysis, an intermetallic compound phase, designated Pb7Bi3 is detected. The formation of an intermetallic compound phase causes a pronounced increase in the electrical resistivity. The Wood's alloy containing-cadmium exhibits mechanical properties superior to both the Newton's and Rose's alloys. The presence of cadmium in Wood's alloy decreases its melting point. Wood's alloy has better properties, which make it useful in various applications such as in protection shields for radiotherapy, locking of mechanical devices and welding at low temperature.

  7. Synthesis and characterization of Pb-Bi bimetal nanoparticles by solution dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yanbao [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Liu Jin [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Cao Liuqin [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Wu Zhishen [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China); Zhang Zhijun [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China)]. E-mail: zhaoyb902@henu.edu.cn; Dang Hongxin [Laboratory of Special Functional Materials, Henan University, Kaifeng 475002 (China)

    2006-09-10

    In this paper, we report a new solution synthetic route to prepare Pb-Bi bimetal nanoparticles from bulk ingot that is different from conventional solution methods. The Pb-Bi nanoparticles were prepared by dispersing directly melt Pb-Bi ingot in a suitable solvent and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and other techniques. Transmission electron microscopy shows that the Pb-Bi nanoparticles appear a spherical shape with an average diameter of 50 nm. X-ray diffraction studies show that the Pb-Bi nanoparticles contain crystalline Pb{sub 7}Bi{sub 3}, Bi and a little amount of PbO. Tribological results show that Pb-Bi nanoparticles as a lubricating additive show good antiwear properties. In addition, the formation mechanism of the Pb-Bi nanoparticles was also discussed.

  8. Pb/PbF/sub 2//BiF/sub 3//Bi thin solid film reversible galvanic cell

    Energy Technology Data Exchange (ETDEWEB)

    Danto, Y.; Poujade, G.; Pistre, J.D.; Lucat, C.; Salardenne, J.

    1978-12-15

    Thin film solid state galvanic cells were made using lead as the anode, PbF/sub 2/ as the electrolyte and BiF/sub 3//Bi as the cathode. The cells were obtained by charging a simple Bi/PbF/sub 2//Bi structure. Such elements develop open-circuit voltages of 353 mV, in good agreement with the theoretical value. The discharge characteristics show a plateau region of several hours. At room temperature current densities of 40 ..mu..A cm/sup -2/ were measured with voltages of about 200 mV. Short-circuit currents larger than 1 mA cm/sup -2/ were obtained. The cells are entirely reversible, and many complete charge-discharge cycles were performed. The evolution of the d.c. internal resistance as a function of discharge is discussed.

  9. Fabrication and properties of poly(vinylidenefluoride)/PbS/Au heterogeneous nanostructures.

    Science.gov (United States)

    Lee, Kwang-Pill; Gopalan, Anantha Iyengar; Park, Jong Wook; Ragupathy, Dhanusuraman; Manesh, Kalayil Manian

    2009-01-01

    We report on the fabrication of polyvinylidenefluoride (PVdF) PVdF/PbS and PVdF/PbS/Au heterogeneous nanostructures by the processes, electrospinning and chemical treatment. Initially electrospinning a solution consisting of PVdF and lead acetate was used to form PVdF nanofibers loaded with Pb ions. Exposure of Pb ions loaded PVdF fibers to H2S resulted in PVdF/PbS nanostructures. The deposition of gold nanoparticles onto PVdF/PbS nanostructures results in PVdF/PbS/Au heterogeneous structure. The existence of PbS particles with an average diameter of 11 nm is evident from field emission transmission electron microscopy (FETEM) image of PVdF/PbS. The results from X-ray diffraction of PVdF/PbS also predict the size of PbS particles as in accordance with FETEM. A blue shift in the optical transition of PbS is noticed in the UV-visible spectrum of PVdF/PbS as a result of quantum confinement effect. The band gap of PbS is influenced by the presence of Au nanoparticles over the PbS particles. An equal atomic weight % of Au and PbS is found in the PVdF/PbS/Au nanostructure as inferred from energy dispersive X-ray spectroscopy (EDX). Photoluminescence (PL) spectra of PVdF/PbS and PVdF/PbS/Au are compared. Emission peaks are noticed at 400 nm and 480 nm for PVdF/PbS and PVdF/PbS/Au nanostructures respectively for an excitation wavelength of 254 nm. The presence of Au nanoclusters in PVdF/PbS/Au diminishes the intensity of photo emission of PbS.

  10. Textures, trace elements, and Pb isotopes of sulfides from the Haopinggou vein deposit, southern North China Craton: implications for discrete Au and Ag-Pb-Zn mineralization

    Science.gov (United States)

    Li, Zhan-Ke; Li, Jian-Wei; Cooke, David R.; Danyushevsky, Leonid; Zhang, Lejun; O'Brien, Hugh; Lahaye, Yann; Zhang, Wen; Xu, Hai-Jun

    2016-12-01

    The Haopinggou deposit in the Xiong'ershan district, southern margin of the North China Craton, comprises numerous Au and Ag-Pb-Zn veins hosted in metamorphic rocks of the Late Archean to early Paleoproterozoic Taihua Group. Two stages of mineralization have been recognized: Stage 1 pyrite-quartz veins and Stage 2 Pb-Zn-sulfide veins. Some pyrite-quartz veins are surrounded or cut by Pb-Zn-sulfide veins, others occur as independent veins. Six generations of pyrite have been identified at Haopinggou: Py1 to Py3 in Stage 1 and Py4 to Py6 in Stage 2. Pyrites from Stage 1 are enriched in Au, As, Co, Ni, and Bi, whereas Stage 2 pyrites contain higher Ag, Pb, Zn, Sn, and Sb. Invisible Au mostly occurs as lattice-bound gold in Py2 (up to 92 ppm Au) and Py3 (up to 127 ppm Au) and has a close relationship with As. Native Au grains are also present in Py3 and likely resulted from mobilization and reprecipitation of the invisible Au previously locked in the precursor pyrite. This view is supported by extensive plastic deformation in Stage 1 pyrite as revealed by electron backscatter diffraction analysis. In Stage 2, Ag is mostly present as lattice-bound silver closely associated with Sb in galena (up to 798 ppm Ag). A variety of silver minerals are also present as inclusions within galena or as interstitial grains. These silver minerals were likely formed via Ag-Cu exchange reaction between tetrahedrite and galena or represent exsolution from galena due to a temperature decrease. Pb isotopic compositions differ remarkably between Stage 1 and Stage 2 sulfides, indicating different sources of lead. Pb in Stage 2 Pb-Zn-sulfide veins is consistent with the Haopinggou porphyry close to the veins. The field, textural, compositional, and lead isotopic data led us to conclude that the early gold-bearing pyrite-quartz veins and late silver-bearing Pb-Zn-sulfide veins likely formed from distinct fluid systems related to discrete mineralization events. Our study suggests that Au and Ag-Pb

  11. Genesis of the Au-Bi-Cu-As, Cu-Mo ± W, and base-metal Au-Ag mineralization at the Mountain Freegold (Yukon, Canada): constraints from Ar-Ar and Re-Os geochronology and Pb and stable isotope compositions

    Science.gov (United States)

    Bineli Betsi, Thierry; Lentz, David; Chiaradia, Massimo; Kyser, Kurt; Creaser, Robert A.

    2013-12-01

    The genesis of mineralized systems across the Mountain Freegold area, in the Dawson Range Cu-Au ± Mo Belt of the Tintina Au province was constrained using Pb and stable isotope compositions and Ar-Ar and Re-Os geochronology. Pb isotope compositions of sulfides span a wide compositional range (206Pb/204Pb, 18.669-19.861; 208Pb/204Pb, 38.400-39.238) that overlaps the compositions of the spatially associated igneous rocks, thus indicating a magmatic origin for Pb and probably the other metals. Sulfur isotopic compositions of sulfide minerals are broadly similar and their δ34S (Vienna-Canyon Diablo Troilite (V-CDT)) values range from -1.4 to 3.6 ‰ consistent with the magmatic range, with the exception of stibnite from a Au-Sb-quartz vein, which has δ34S values between -8.1 and -3.1 ‰. The δ34S values of sulfates coexisting with sulfide are between 11.2 and 14.2 ‰; whereas, those from the weathering zone range from 3.7 to 4.3 ‰, indicating supergene sulfates derived from oxidation of hypogene sulfides. The δ13C (Vienna Peedee Belemnite (VPDB)) values of carbonate range from -4.9 to 1.1 ‰ and are higher than magmatic values. The δ18O (V-SMOW) values of magmatic quartz phenocrysts and magmatic least-altered rocks vary between 6.2 and 10.1 ‰ and between 5.0 and 10.1 ‰, respectively, whereas altered magmatic rocks and hydrothermal minerals (quartz and magnetite) are relatively 18O-depleted (4.2 to 7.9 ‰ and -6.3 to 1.5 ‰, respectively). Hydrogen isotope compositions of both least-altered and altered igneous rock samples are D-depleted (from -133 to -161 ‰ Vienna-Standard Mean Ocean Water (V-SMOW)), consistent with differential magma degassing and/or post-crystallization exchange between the rocks and meteoric ground water. Zircon from a chlorite-altered dike has a U-Pb crystallization age of 108.7 ± 0.4 Ma; whereas, the same sample yielded a whole-rock Ar-Ar plateau age of 76.25 ± 0.53 Ma. Likewise, molybdenite Re-Os model ages range from 75.8 to

  12. Surface tension of liquid Au-Bi-Sn alloys

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The surface tension of a promising lead-free solder Au-Bi-Sn alloys was investigated both by the sessile-drop method and calculation. Experimental measurements were carried out for two cross-sections with the constant gold to bismuth ration of 1:1 and 1:2. For all the investigated compositions, decrease of the surface tension is observed with increasing temperature. Meanwhile, the surface tension values were also calculated based on Butler's equation, with using the newest research on thermodynamics data of...

  13. Synthesis of BiPbSrCaCuO superconductor

    Science.gov (United States)

    Hults, William L.; Kubat-Martin, Kimberly A.; Salazar, Kenneth V.; Phillips, David S.; Peterson, Dean E.

    1994-01-01

    A process and a precursor composition for preparing a lead-doped bismuth-strontium-calcium-copper oxide superconductor of the formula Bi.sub.a Pb.sub.b Sr.sub.c Ca.sub.d Cu.sub.e O.sub.f wherein a is from about 1.7 to about 1.9, b is from about 0.3 to about 0.45, c is from about 1.6 to about 2.2, d is from about 1.6 to about 2.2, e is from about 2.97 to about 3.2 and f is 10.+-.z by reacting a mixture of Bi.sub.4 Sr.sub.3 Ca.sub.3 Cu.sub.4 O.sub.16.+-.z, an alkaline earth metal cuprate, e.g., Sr.sub.9 Ca.sub.5 Cu.sub.24 O.sub.41, and an alkaline earth metal plumbate, e.g., Ca.sub.2-x Sr.sub.x PbO.sub.4 wherein x is about 0.5, is disclosed.

  14. Transverse Peltier effect in tilted Pb -Bi2Te3 multilayer structures

    Science.gov (United States)

    Kyarad, A.; Lengfellner, H.

    2006-11-01

    A transverse Peltier effect has been observed in artificially created tilted Pb -Bi2Te3 multilayer structures. Multilayer stacks consisting of alternating layers of Pb and n-type Bi2Te3 have been prepared by a heating procedure and showed large thermoelectric anisotropy up to ΔS ≅200μV/K, depending on thickness ratio p =dBiTe/dPb, where dBiTe and dPb are the thicknesses of Bi2Te3 and Pb layers, respectively. Tilted samples were obtained by cutting stacks obliquely to the stack axis. Due to large ΔS and large electrical but small heat conductivity, samples showed temperature differences transverse to applied currents up to 22K.

  15. Enthalpies of mixing of the liquid phase in the ternary system Ag-Au-Bi

    Energy Technology Data Exchange (ETDEWEB)

    Zoro, E. [Laboratoire de Chimie Physique Minerale et Bioinorganique, EA401, Fac. Pharm., Universite de Paris XI, 5 rue JB Clement, 92296 Chatenay Malabry (France) and Laboratoire de Physico-Chimie de l' Etat Solide, UMR 8648, Bat 410-415, 91405 Orsay Cedex (France)]. E-mail: zoroe@netcourrier.com; Boa, D. [Laboratoire de Thermodynamique et de Physico-Chimie du Milieu, Universite d' Abobo-Adjame, UFR-SFA, 02 BP801 Abidjan 02, Cote d' Ivoire, Africa (Ivory Coast); Servant, C. [Laboratoire de Physico-Chimie de l' Etat Solide, UMR 8648, Bat 410-415, 91405 Orsay Cedex (France); Legendre, B. [Laboratoire de Chimie Physique Minerale et Bioinorganique, EA401, Fac. Pharm., Universite de Paris XI, 5 rue JB Clement, 92296 Chatenay Malabry (France)

    2005-08-02

    The enthalpies of mixing of the liquid phase of the Ag-Au-Bi ternary alloys along the sections Ag {sub x}Bi{sub 1-x}-Au (x = 0.11, 0.10 and 0.24) and Au {sub x}Bi{sub 1-x}-Ag (x = 0.11 and 0.27) have been determined at 673 and 773 K. We used a SETARAM devised heat flow calorimeter of Tian-Calvet type. The values obtained are almost compatible with estimations from Scientific Group of Thermodata Europe (SGTE) binary database without adding ternary thermodynamic excess parameters. However, slight discrepancies are observed. The result of this study is useful tools for the Ag-Au-Bi ternary system thermodynamic computer optimization in process by the authors.

  16. Synthesis and characterization of PbO-CdO nanocomposite and its effect on (Bi,Pb)-2223 superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Yahya, Nabil A.A. [Thamar University, Physics Department, Faculty of Education, Thamar (Yemen); Al-Gaashani, R. [Thamar University, Physics Department, Faculty of Education, Thamar (Yemen); Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU), Doha (Qatar); Abd-Shukor, R. [Universiti Kebangsaan Malaysia, School of Applied Physics, Bangi, Selangor (Malaysia)

    2017-03-15

    A PbO-CdO nanocomposite-added Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} ((Bi,Pb)-2223) superconductor has been prepared. The effect of the PbO-CdO nanocomposite addition on the transport critical current density (J{sub c}) of (Bi,Pb)-2223 superconductor was investigated. The transition temperature (T{sub c-onset}), zero electrical resistance temperature (T{sub c-R=0}), and J{sub c} of the samples were measured by the four-probe method. Phase formation, structure, and microstructure of samples were investigated. The distribution of nanoparticle size was determined. The results indicated that the PbO-CdO-added samples showed larger grain size and an increased volume fraction of high-T{sub c} phase (Bi-2223) compared to the non-added sample. A slight increase in T{sub c-R=0} of x = 0.15 wt% was observed. J{sub c} of the PbO-CdO nanocomposite-added samples was significantly higher than for the non-added sample. That could be explained by the possibility that the PbO-CdO nanocomposite acts as an effective flux pinning center in (Bi,Pb)-2223. At 77 K, J{sub c} of x = 0.15 wt% added sample was more than 20 times larger than J{sub c} of the non-added sample (x = 0 wt%). A combined effect of enhanced flux pinning, increased fraction of high-T{sub c} phase and improved grain size, which led to increase in the J{sub c} of added samples, is discussed. (orig.)

  17. Synthesis and characterization of PbO-CdO nanocomposite and its effect on (Bi,Pb)-2223 superconductor

    Science.gov (United States)

    Yahya, Nabil A. A.; Al-Gaashani, R.; Abd-Shukor, R.

    2017-03-01

    A PbO-CdO nanocomposite-added Bi1.6Pb0.4Sr2Ca2Cu3O10 ((Bi,Pb)-2223) superconductor has been prepared. The effect of the PbO-CdO nanocomposite addition on the transport critical current density ( J c) of (Bi,Pb)-2223 superconductor was investigated. The transition temperature ( T c-onset), zero electrical resistance temperature ( T c- R=0), and J c of the samples were measured by the four-probe method. Phase formation, structure, and microstructure of samples were investigated. The distribution of nanoparticle size was determined. The results indicated that the PbO-CdO-added samples showed larger grain size and an increased volume fraction of high- T c phase (Bi-2223) compared to the non-added sample. A slight increase in T c- R=0 of x = 0.15 wt% was observed. J c of the PbO-CdO nanocomposite-added samples was significantly higher than for the non-added sample. That could be explained by the possibility that the PbO-CdO nanocomposite acts as an effective flux pinning center in (Bi,Pb)-2223. At 77 K, J c of x = 0.15 wt% added sample was more than 20 times larger than J c of the non-added sample ( x = 0 wt%). A combined effect of enhanced flux pinning, increased fraction of high- T c phase and improved grain size, which led to increase in the J c of added samples, is discussed.

  18. Radioisotope Thermoelectric Generators Based on Segmented BiTe/PbTe-BiTe/TAGS/PbSnTe

    Science.gov (United States)

    McAlonan, Malachy; Patel, Kalpesh; Cummer, Keith

    2006-01-01

    This paper reports on Phase 1 of a multifaceted effort to develop a more efficient radioisotope thermoelectric generator (RTG) for future NASA missions. The conversion efficiency goal is 10% or higher at a power level of 20 watt or higher. The thermoelectric (T/E) efficiency achievable with present T/E materials is about 8% for favorable temperatures. Thermoelectric converter designs, T/E material properties, and T/E couple thermal and electrical performance were investigated in Phase 1 of this program to find paths to improve conversion efficiency. T/E properties can be improved by optimizing the composition of the materials and by improving the micro structural characteristics such as homogeneity, grain size, and phases present. T/E couple performance can be improved by reducing the electrical and thermal contact resistances of the couple and within the segmented T/E elements. Performance and reliability improvements can be achieved by reducing the thermo-mechanical stresses, improving the quality of the bonds and interfaces, minimizing the number of required bonds, and reducing the degradation rates of both the T/E materials and the bonds. This paper focuses on one portion of the activity, i.e., the design of a small converter. In the converter design effort, a prototypic 20-watt device, suitable for use with a single general-purpose heat source (GPHS), was built using an optimized converter design of segmented thermoelectric elements of heritage composition. The 20-watt prototype achieved the power predicted for the test conditions. The chosen couple design used segmented BiTe/PbTe for the n-type element and BiTe/TAGS/PbSnTe, for the p-type T/E element. Use of the BiTe segment exploits the opportunity of the small RTG to operate at lower heat rejection temperatures and results in much higher conversion efficiency, the main objective of the NASA program. Long term data on similarly segmented couples at Teledyne together with the 20-watt module test results

  19. Interaction Kinetics between Sn-Pb Solder Droplet and Au/Ni/Cu Pad

    Institute of Scientific and Technical Information of China (English)

    Fuquan LI; Chunqing WANG; Yanhong TIAN

    2006-01-01

    The interfacial phenomena of the Sn-Pb solder droplet on Au/Ni/Cu pad are investigated. A continuous AuSn2and needle-like AuSn4 are formed at the interface after the liquid state reaction (soldering). The interfacial reaction between the solder and Au layer continues during solid state aging with AuSn4 breaking off from the interface and felling into the solder. The kinetics of Au layer dissolution and diffusion into the solder during soldering and aging is analyzed to elucidate intermetallic formation mechanism at the solder/Au pad interface.The concentration of Au near the solder/pad interface is identified to increase and reach the solubility limit during the period of liquid state reaction. During solid state reaction, the thickening of Au-Sn compound is mainly controlled by element diffusion.

  20. Simulation of Mechanical Stress on Stainless Steel for Pb-Bi Corrosion Test by Using ABAQUS

    Science.gov (United States)

    Irwanto, D.; Mustari, A. P. A.; Budiman, B. A.

    2017-03-01

    Pb-Bi eutectic with its advantageous is proposed to be utilized as a coolant in the GEN IV type of rSeactor. However, high temperature corrosion when contact with stainless steels is one of the issues of Pb-Bi eutectic utilization. It is known that in the environment of high temperature Pb-Bi, mechanical strength of stainless steel may decrease. Thus, simulation of mechanical stress working on stainless steel during in-situ bending test by using ABAQUS was conducted. Several bending degrees were simulated at high temperature to obtain the mechanical stress information. Temperature condition was strongly affect the stress vs. displacement profile. The reported mechanical strength reduction percentage was used to draw predicted mechanical stress under high temperature Pb-Bi environment.

  1. Dissolution kinetics of nanoscale liquid Pb/Bi inclusions at a grain boundary in aluminum

    DEFF Research Database (Denmark)

    Prokofjev, S.I.; Johnson, Erik; Zhilin, V.M.

    2008-01-01

    In situ transmission electron microscopy is used to study dissolution of liquid single-phase Pb/Bi inclusions attached to a grain boundary in an alloy of Al99.29Pb0.65Bi0.06 at temperatures of 343, 370, and 389 degrees C, respectively. The initial size of the inclusions was smaller than 60 nm....... Dissolution of the inclusions was observed until their complete disappearance. Digitized video recordings of the process of dissolution were used to obtain the dependence of the inclusion size with time. The kinetics of the dissolution of the grain boundary inclusions can be described with a model where...... it is assumed that grain-boundary diffusion of Pb and Bi is the controlling mechanism. The high value (2.3 eV) of the apparent activation enthalpy of dissolution indicates that the process is likely governed by the large negative enthalpies of solubility of Pb and Bi in Al....

  2. Preparation of Pt Au/C and Pt Au Bi/C electrocatalysts using electron beam irradiation for ethanol electro-oxidation in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Geraldes, Adriana N.; Cardoso, Elisangela S.Z.; Gomes, Thiago B.; Linardi, Marcelo; Oliveira Neto, Almir; Spinace, Estevam V., E-mail: dfsilva@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Pt Au/C (50:50) and PtAuBi/C electrocatalysts with Pt:Au:Bi atomic ratios of 50:40:10, 50:30:20 and 50:10:40 were prepared in water/2-propanol using electron beam irradiation. The materials were characterized by X-ray diffraction (XRD) and the electro-oxidation of ethanol was studied by chronoamperometry at room temperature. The X-ray diffraction measurements for all electrocatalysts prepared showed four peaks, which are associated with the planes of the face-centered cubic (fcc) structure characteristic of Pt and Pt alloys. For PtAuBi/C it was also observed the presence of a mixture of BiPt alloys and bismuth phases. The average crystallite sizes for Pt/C, PtAu/C, PtAuBi/C (50:40:10), PtAuBi/C (50:30:20) and PtAuBi/C (50:10:40) were in the range of 2.0 - 4.0 nm. The activity of the electrocatalysts for ethanol oxidation in alkaline medium showed that PtAuBi/C (50:40:10) had a higher performance for ethanol oxidation compared to others electrocatalysts prepared. (author)

  3. Energy conversion efficiencies of thermoelectric pallets (Bi2Pb3,Bi2Te3 and Pb2Te3) under the influences of electric and magnetic fields

    Science.gov (United States)

    Singh, Jaspal; Verma, S. S.

    2013-06-01

    This paper aims to introduce the ability of thermo electric pallets to convert waste heat into electricity and also about the effect of electric or magnetic fields, which can exist already or applied in the conditions of their operation. Three thermo electric pallets (Bi2Pb3,Bi2Te3 and Pb2Te3) of cylindrical dimensions are prepared by 15mm mixture of different compositions. Thermo emf generations are carried out in the normal mode and then under the influence of applied electric and magnetic fields of different magnitudes in the temperature range of 460K.

  4. Phase transition in vortex system in Bi2212:Pb monocrystal

    CERN Document Server

    Uspenskaya, L S; Rakhmanov, A L

    2002-01-01

    Penetration of the magnetic flux into the (Bi sub 0 sub . sub 8 sub 4 Pb sub 0 sub . sub 1 sub 6) sub 2 sub . sub 2 Sr sub 2 CaCu sub 2 O sub 8 high-temperature superconductor monocrystal is studied thorough the magnetooptical method in the crossed magnetic fields. It is shown that the magnetic flux penetration in the low-temperature areas is anisotropic: it moves primarily along the magnetic field, applied in the sample plane, and this anisotropy grows with the temperature growth. At the temperature of T sub m = 54 +- 2 K there takes place sharp change in the character of the magnetic field penetration into the superconductor, whereby the direction of the flux motion discontinues to be dependent on the direction and value of the magnetic field applied in the sample plane. This effect is interpreted within the frames of representations on the phase transition in the vortex system connected with a sharp decrease in the correlations of the vortex position in the different CuO-planes

  5. Photocatalytic degradation of organic dyes on visible-light responsive photocatalyst PbBiO 2Br

    Science.gov (United States)

    Shan, Zhichao; Wang, Wendeng; Lin, Xinping; Ding, Hanming; Huang, Fuqiang

    2008-06-01

    The layered compound of lead bismuth oxybromide PbBiO 2Br, prepared by conventional solid-state reaction method, has an optical band gap of 2.3 eV, and possesses a good visible-light-response ability. The references, PbBi 2Nb 2O 9, TiO 2-xN x, BiOBr and BiOI 0.8Cl 0.2, which are excellent visible-light-response photocatalysts, were applied to comparatively understand the activity of PbBiO 2Br. Degradation of methyl orange and methylene blue was used to evaluate photocatalytic activity. The results show that PbBiO 2Br is more photocatalytically active than PbBi 2Nb 2O 9, TiO 2-xN x and BiOBr under visible light.

  6. Control of oxidizing potential of Pb and Pb-Bi coolants

    Directory of Open Access Journals (Sweden)

    Vladimir Vladimirovich Ulyanov

    2015-12-01

    Full Text Available Analytical and experimental data on formation of oxygen oxidizing potential in heavy liquid metal coolants (Pb and Pb-Bi eutectic was considered. It was revealed that oxygen could be both dissolved in these coolants and included in various thermodynamically unstable oxide compounds. In case of heavy liquid metal coolant (HLMC flowing in non-isothermal circuit, these compounds are broken down with oxygen release or formed fixing dissolved oxygen. The amount of oxygen, which is present in HLMC and exhibits its activity with temperature, could be much greater than the value detected by oxygen sensor. That is why HLMC possess internal oxygen reserves inhibiting corrosion in the circuits. Presence of thermodynamically unstable oxide phases in the above coolants, non-isoconcentration distribution of active oxygen, and impossibility to currently obtain the analytical relationship showing dissolved oxygen distribution make it necessary to use at least three oxygen sensors for studying processes of formation of HLMC oxidizing potential. These sensors should be located in the zones of max and min temperatures (tmax, tmin and in that at t=450-550°С. In order to assure the most accurate estimate it is reasonable to provide additional two or more sensors in the zone at t=450-550°С.

  7. Depth profile of production yields of natPb(p, xn) 206,205,204,203,202,201Bi nuclear reactions

    Science.gov (United States)

    Mokhtari Oranj, Leila; Jung, Nam-Suk; Kim, Dong-Hyun; Lee, Arim; Bae, Oryun; Lee, Hee-Seock

    2016-11-01

    Experimental and simulation studies on the depth profiles of production yields of natPb(p, xn) 206,205,204,203,202,201Bi nuclear reactions were carried out. Irradiation experiments were performed at the high-intensity proton linac facility (KOMAC) in Korea. The targets, irradiated by 100-MeV protons, were arranged in a stack consisting of natural Pb, Al, Au foils and Pb plates. The proton beam intensity was determined by activation analysis method using 27Al(p, 3p1n)24Na, 197Au(p, p1n)196Au, and 197Au(p, p3n)194Au monitor reactions and also by Gafchromic film dosimetry method. The yields of produced radio-nuclei in the natPb activation foils and monitor foils were measured by HPGe spectroscopy system. Monte Carlo simulations were performed by FLUKA, PHITS/DCHAIN-SP, and MCNPX/FISPACT codes and the calculated data were compared with the experimental results. A satisfactory agreement was observed between the present experimental data and the simulations.

  8. Effect of cooling rate on evolution of superconducting phases during decomposition and recrystallization of (Bi,Pb)-2223 core in Ag-sheathed tape

    Institute of Scientific and Technical Information of China (English)

    LI Jingyong; LI Jianguo; ZHENG Huiling; LI Chengshan; LU Yafeng; ZHOU Lian

    2006-01-01

    The reformation of (Bi,Pb)-2223 from the liquid or melt is very important for a melting process of (Bi,Pb)-2223 tape. By combination of quenching experiment with X-ray diffraction (XRD) analysis, the effect of cooling rate on the evolution of three superconducting phases in the (Bi,Pb)-2223 core of Ag-sheathed tape was investigated. The results show that (Bi,Pb)-2223 reformation from the melt seems to experience different routes during slowly cooling at different rates. One is that (Bi,Pb)-2223 phase reformed directly from the melt, and no Bi-2212 participate in this process. The other is that (Bi,Pb)-2223 is converted from the intermediate product, Bi-2212, which formed from the melt during the first cooling stage. Due to the inherent sluggish formation kinetics of (Bi,Pb)-2223 from Bi-2212, only partial (Bi,Pb)-2223 can finally be reformed with the second route.

  9. Photocatalytic Mineralization of Organic Acids over Visible-Light-Driven Au/BiVO4 Photocatalyst

    Directory of Open Access Journals (Sweden)

    Kanlaya Pingmuang

    2013-01-01

    Full Text Available Au/BiVO4 visible-light-driven photocatalysts were synthesized by coprecipitation method in the presence of sodium dodecyl benzene sulfonate (SDBS as a dispersant. Physical characterization of the obtained materials was carried out by X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive X-ray spectroscopy (EDX, UV-Vis diffuse reflectance spectroscopy (DRS and Brunauer, and Emmett and Teller (BET specific surface area measurement. Photocatalytic performances of the as-prepared Au/BiVO4 have also been evaluated via mineralizations of oxalic acid and malonic acid under visible light irradiation. XRD and SEM results indicated that Au/BiVO4 photocatalysts were of almost spherical particles with scheelite-monoclinic phase. Photocatalytic results showed that all Au/BiVO4 samples exhibited higher oxalic acid mineralization rate than that of pure BiVO4, probably due to a decrease of BiVO4 band gap energy and the presence of surface plasmon absorption upon loading BiVO4 with Au as evidenced from UV-Vis DRS results. The nominal Au loading amount of 0.25 mol% provided the highest pseudo-first-order rate constant of 0.0487 min−1 and 0.0082 min−1 for degradations of oxalic acid (C2 and malonic acid (C3, respectively. By considering structures of the two acids, lower pseudo-first-order rate constantly obtained in the case of malonic acid degradation was likely due to an increased complexity of the degradation mechanism of the longer chain acid.

  10. EXAFS Studies of (Pb,Cd) 1212 phase superconductor and (Bi,Cd)1212 phase compound

    Institute of Scientific and Technical Information of China (English)

    YeTao; ShiqiangWei; 等

    1999-01-01

    We synthesized (Pb,Cd)Sr2(Y,Ca)Cu2O7+x,phase superconductor.After substitution of Pb with Bi,the BiCd1212 phase shows no superconductivity.Although previous EXAFS study has shown the local structure environment of the Cu is similar in both compounds,EXAFS results of Bi and Pb here demonstrate that σ2 of Pb-Oin-plane is larger than that of Bi-O inplane,whereas σ2 of Pb-Oapical is smaller than that of Bi-O,wherase σ2 of Pb-O apical is smaller than that of Bi-Oapical.The Sr shell features are also differnet,it appeared that superconductivity needs some disorder .in carrier reservoir layer,which is due to the substitutional defect caused by different ionic radii.

  11. A facile method of fabricating PbBi alloy nanowires with controlled component proportion

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xue-wei [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Tianjin Key Lab for Photoelectric Materials and Devices, Tianjin 300384 (China); He, Zhao-cheng; Li, Ju-shan [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Yuan, Zhi-hao, E-mail: zhyuan@tjut.edu.cn [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Display Materials and Photoelectric Devices (Tianjin University of Technology), Ministry of Education, Tianjin 300384 (China)

    2014-05-15

    Highlights: • A method of high temperature melting is developed to fabricate PbBi nanowires. • The composition controllable and homogeneous PbBi nanowires can be synthesized. • The component proportion is controlled by adjusting electrodeposition time. • Pores of AAO play an important role during the formation of alloy nanowires. - Abstract: The ability of controlled component proportion for metallic alloy nanowires is still rather limited even after well over a decade of intensive research efforts. Here, a very simple method of high temperature melting in the pores of anodic aluminum oxide templates is developed to fabricate low melting point metallic alloy nanowires, in which the component proportion of elements can be controlled by adjusting electrodeposition time in the separate electrolytes. Taking the fabrication of PbBi alloy nanowires as example, we show how to control the uniform composition and component proportion of metallic alloy nanowires. The PbBi alloy nanowire arrays with three different atomic ratios of Bi–10 at.%, 30 at.%, 80 at.% respectively are successfully fabricated. The morphologies and composition of PbBi alloy nanowires are investigated by field-emission scanning electron microscopy and transmission electron microscopy equipped with X-ray energy dispersive spectroscopy analyzer, and the crystal structures are determined by X-ray diffractometer. These results of experiments indicate that the composition controllable and homogeneous alloy nanowire arrays can be synthesized using this new method.

  12. E ectofGoldNanoparticlesonthePhotocatalytic and Photo electro chemical Performance of Au Mo dified BiVO4

    Institute of Scientific and Technical Information of China (English)

    Mingce Long; Jingjing Jiang; Yan Li; Ruqiong Cao; Liying Zhang; Weimin Cai

    2011-01-01

    An efficient visible light driven photocatalyst, gold nanoparticles (NPs) modified BiVO4 (Au/BiVO4), has been synthesized by deposition-precipitation with urea method. Au/BiVO4 exhibits enhanced pho-tocatalytic activity for phenol degradation underλ>400 nm irradiation but negligible activity underλ>535 nm, indicating that the surface plasmon resonance (SPR) effect is too weak for organic photodegradation. According to the photoelectrochemical results of the porous powder electrodes of BiVO4 and Au/BiVO4, the SPR effect of Au NPs has been assessed. The role of Au NPs as electron sinks or sources, which is controllable by incident photon energy and applied potentials, has been discussed.

  13. Temperature-pressure phase diagram of cubic Laves phase Au2Pb

    Science.gov (United States)

    Chen, K. W.; Graf, D.; Besara, T.; Gallagher, A.; Kikugawa, N.; Balicas, L.; Siegrist, T.; Shekhter, A.; Baumbach, R. E.

    2016-01-01

    The temperature (T ) as a function of pressure (P ) phase diagram is reported for the cubic Laves phase compound Au2Pb, which was recently proposed to support linearly dispersing topological bands, together with conventional quadratic bands. At ambient pressure, Au2Pb exhibits several structural phase transitions at T1=97 K , T2=51 K , and T3=40 K with superconductivity below Tc=1.2 K . Applied pressure results in a rich phase diagram where T1,T2, and T3 evolve strongly with P and a possible new phase is stabilized for P >0.64 GPa that also supports superconductivity below 1.1 K. These observations suggest that Au2Pb is an ideal system in which to investigate the relationship between structural degrees of freedom, band topology, and resulting anomalous behaviors.

  14. Behavior and influence of Pb and Bi in Ag-Cu-Zn brazing alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effects of trace content of Pb and Bi elements on the spreading property and the strength of brazed joints of Ag-Cu-Zn filler metal have been studied. The results show that Pb has little effect on both above properties, and Bi has remarkable influence on the spreading property but little effect on the strength of brazed joint. Pb and Bi dissolve into the Ag-Cu-Zn matrix and will melt and gather at lower temperature when that alloy is being heated. Therefore a liquid forms on the surface of the Ag-Cu-Zn alloy and overlays the melting alloy, then keeps the filler metal away from the materials being joined, and so decreases the spreading property.

  15. The effect of low Au concentrations on the properties of eutectic Sn/Pb

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, P.A.

    1992-05-01

    This study was of the effects moderately low Au concentrations ({le} 10 wt%) have on the mechanical properties and microstructure of an eutectic Sn/Pb alloy. Vibration (60--90 Hz swept sine wave for 30 hours) and thermal cycling (0--110C for 1450 cycles) reliability tests were performed on fine pitch leaded chip carriers using eutectic Sn/Pb solder on PCBs (printed circuit boards) with 0, 5, 10, 20, and 50{mu}in nominal Au thicknesses. Testing was also performed on double shear creep specimens consisting of arrays of regular pitch joints. There was a dramatic increase in the number of joints containing voids with increasing Au concentration, an effect more pronounced in the creep joints than in the reliability joints. These voids tended to coalesce and grow during rework simulation of the reliability joints. AuSn{sub 4} intermetallics present in toe of 4.8 wt% (50 {mu}in) Au vibration joints rotated from initial vertical perpendicular to surface of PCB metallization, solidification positions to roughly horizontal (parallel to plating surface) orientations during rework simulation and during aging of the parts. The AuSn{sub 4} intermetallics in the toe of the 4.8 wt% (50{mu}in) Au reflowed joints also rotated after vibration testing. No joint failures were observed in either vibration tested or thermally cycled specimens. Cracks formed in some of the vibration tested specimen joints under the heel of the gull-wing lead at Pb-rich phases. Thermally cycled specimens showed eutectic microstructure and intermetallic coarsening without crack formation. Creep tests showed loss of the superplasticity in eutectic Sn/Pb alloys with even the lowest Au concentration tested of 0.2 wt% Au. Intermetallic rotation was not a factor in crack propagation, but void presence was. Cracks tended to form in joints containing voids before forming in void-free joints. Crack propagation followed Sn/Sn grain boundaries and Sn/Pb phase boundaries from Pb-rich phase to Pb-rich phase.

  16. Synthesis of highly phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor

    Science.gov (United States)

    Dorris, Stephen E.; Poeppel, Roger B.; Prorok, Barton C.; Lanagan, Michael T.; Maroni, Victor A.

    1994-01-01

    An article and method of manufacture of (Bi,Pb)-Sr-Ca-Cu-O superconductor. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi,Pb)-Sr-Ca-Cu-O superconductor.

  17. Investigation of Terahertz Emission from BiVO4 /Au Thin Film Interface

    NARCIS (Netherlands)

    Kumar, N.; Abdi, F.F.; Trzesniewski, B.; Smith, W.A.; Planken, P.C.M.; Adam, A.J.L.

    2015-01-01

    We demonstrate emission of terahertz pulses from a BiVO4/Au thin film interface, illuminated with femtosecond laser pulses. Based on the experimental observations, we propose that the most likely cause of the THz emission is the Photo-Dember effect caused by the standing wave intensity distribution

  18. Transverse peltier effect in Pb-Bi{sub 2}Te{sub 3} multilayer structures

    Energy Technology Data Exchange (ETDEWEB)

    Reitmaier, Christina; Walther, Franziska; Kyarad, Amir; Lengfellner, Hans [University of Regensburg (Germany)

    2009-07-01

    Metal-semiconductor multilayer structures show, according to model calculations, large anisotropy in their electrical and thermal transport properties. Multilayer stacks consisting of alternating layers of Pb and n-type Bi{sub 2}Te{sub 3} and prepared by a heating procedure displayed large thermoelectric anisotropy up to {delta}S{approx}200 {mu} V/K, depending on the thickness ratio p=d{sub BiTe}/d{sub Pb}, where d{sub BiTe} and d{sub Pb} are the thicknesses of Bi{sub 2}Te{sub 3} and Pb layers, respectively. From multilayer stacks, tilted samples with layers inclined with respect to the sample surface where obtained by cutting stacks obliquely to the stack axis. Non-zero off-diagonal elements in the Seebeck-tensor describing the thermopower of tilted samples allow for the occurance of a transverse Peltier effect. Experimental results demonstrate cooling by the transverse Peltier effect and are compared to model calculations.

  19. Properties and Structure of the F-doped (Bi, Pb)-Sr-Ca-Cu-O Superconductor

    Institute of Scientific and Technical Information of China (English)

    高孝恢; 王小刚; 蒋淑芬; 李洁; 高赛; 郑国栋

    1994-01-01

    By using TEM, XPS, IR, position annihilation and differential specific heat measurements, the properties and structure of the F-doped (Bi, Pb)-Sr-Ca-Cu-O superconductor have been studied. The results show that the fluorine atoms are homogeneously distributed in superconducting phase and substituted for the oxygen atoms at O(2) crystallographic sites; the Pb-F and Cu-F bonds are formed. F-doping results in the variance of the incommensurate modulation structure, the increase of the point defects and chemical pressure, the enhancement of flux pinning effect and the change of the electronic structure and chemical bond, and greatly improves superconductive properties of the 2223 phase (Bi, Pb)-Sr-Ca-Cu-O.

  20. Magnetic and structural properties of Bi(2223doped by pb and Sb

    Directory of Open Access Journals (Sweden)

    H. Salamati

    1998-04-01

    Full Text Available   In a systematic approach, we have investigated the effect of the presence of Pb and Sb in the Bi site in a BSCCO (2223 phase superconductor. There are some contradictory reports in substitution of Sb in the Bi site. Some researchers report an increase in the Tc of these materials. So, we have made an accurate stoichiometry of these superconductors and selected extra pure starting materials with appropriate ratios of Pb+Sb.   The susceptility of these samples have been measured and the structures of the systems have been studied by SEM and XRD. The results of this investigation show that, Although the presence of Pb is essential for formation of (2223 phase, but addition of small amount of Sb helps to stabilize and enhance the ratio of higher phase. Our results show that, presence of Sb would raise the critical current density, but would not affect the Tc of these superconductors.

  1. Measurement of activation cross-sections for high-energy neutron-induced reactions of Bi and Pb

    Science.gov (United States)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Naik, Haladhara; Shahid, Muhammad; Lee, Manwoo

    2015-08-01

    The cross-sections for 209Bi(n, 4n)206Bi, 209Bi(n, 5n)205Bi, natPb(n, xn)204mPb, natPb(n, xn)203Pb, natPb(n, xn)202mPb,natPb(n, xn)201Pb, natPb(n, xn)200Pb, natPb(n, αxn)203Hg and natPb(n, p xn)202Tl reactions were determined at the Korean Institute of Radiological and Medical Sciences (KIRAMS), Korea in the neutron energy range of 15.2 to 37.2 MeV. The above cross-sections were obtained by using the activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutron used for the above reactions are based on the 9Be(p, n) reaction. Simulations of the spectral flux from the Be target were done using the MCNPX program. The cross-sections were estimated with the TALYS 1.6 code using the default parameter. The data from the present work and literature were compared with the data from the EAF-2010 and the TENDL-2013 libraries, and calculated values of TALYS 1.6 code. It shows that appropriate level density model, the γ-ray strength function, and the spin cut-off parameter are needed to obtain a good agreement between experimental data and theoretical values from TALYS 1.6 code.

  2. Polymorphism in Bi{sub 5}Pb{sub 3}O{sub 10.5}

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Akiteru; Kitami, Yoshizo; Takenouchi, Satoshi [National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan); Boivin, J.C. [ENSCL et USTL, Villeneuve d`Ascq (France). Lab. de Cristallochimie et Physicochimie du Solide; Sammes, N. [Univ. of Waikato, Hamilton (New Zealand). Centre for Technology

    1999-04-01

    This paper describes the phase and structural relations between three polymorphs of Bi{sub 5}Pb{sub 3}O{sub 10.5}. The low-temperature stable phase named {beta}{sub L} crystallizes in the triclinic system with a = 14.903(1) {angstrom}, b = 14.184(1) {angstrom}, c = 7.2115(7) {angstrom}, {alpha} = 97.216(8){degree}, {beta} = 118.434(6){degree}, {gamma} = 80.647(8){degree}, and Z = 4. The unquenchable high-temperature stable phase labeled {beta} forms a solid solution and has an anti-{alpha}-AgI-type structure with the space group Im3m; {beta}-Bi{sub 5}Pb{sub 3}O{sub 10.5} has a = 4.40 {angstrom} at 600 C and Z = 2 (Bi{sub 5/8}Pb{sub 3/8}O{sub 10.5/8}). The metastable phase termed {beta}{sub 2} also forms a solid solution and crystallizes in the tetragonal system with the possible space group P4{sub 2}/n; {beta}{sub 2}-Bi{sub 5}Pb{sub 3}O{sub 10.5} has a = 12.132(1) {angstrom}, c = 20.059(2) {angstrom}, and Z = 9. The {beta}{sub L} phase transforms to the {beta} phase at about 585 C; on subsequent cooling, at about 560 C, the {beta} phase changes to the {beta}{sub 2} phase which is kept to room temperature. The {beta}{sub 2} phase reverts to the {beta}{sub L} phase by annealing at low temperatures, e.g., at 500 C. The structure of {beta}{sub L}-Bi{sub 5}Pb{sub 3}O{sub 10.5} is based on a pseudo-bcc {beta}-type subcell, and the transformation matrix is ({minus}2, 2, 2)/(1, {minus}1, 3)/(3/2, {1/2}, {minus}{1/2}). The structure of the {beta}{sub 2} phase is connected to that of red tetragonal PbO-type structure according to (3, 0, 0)/(0, 3, 0)/(0, 0, 4). From the viewpoint of the lone pair of electrons on Bi{sup 3+} and Pb{sup 2+}, the metastability of the {beta}{sub 2} phase is discussed.

  3. High-pressure anisotropic distortion of Pb3Bi2S6

    DEFF Research Database (Denmark)

    Olsen, Lars Arnskov; Balic Zunic, Tonci; Makovicky, Emil

    2008-01-01

    The compound Pb3Bi2S6 is investigated by X-ray diffraction on single crystals in a diamond-anvil cell between 0.0001 and 10.5 GPa. It undergoes a first-order phase transition at hydrostatic pressure between 3.7 and 4.9 Gpa. The space group symmetry changes from Bbmm to Pbnm, and the unit-cell vol......The compound Pb3Bi2S6 is investigated by X-ray diffraction on single crystals in a diamond-anvil cell between 0.0001 and 10.5 GPa. It undergoes a first-order phase transition at hydrostatic pressure between 3.7 and 4.9 Gpa. The space group symmetry changes from Bbmm to Pbnm, and the unit...... of chemical bonds in the structure. In the case of Pb3Bi2S6 the transition is achieved by the change of the archetypal architecture of the structure-building modules from a PbS-like to  SnS-like arrangement and a loss of mirror planes on the contact surfaces of modules. The phase transition is reversible...

  4. Lignin-AuNPs liquid marble for remotely-controllable detection of Pb2+

    Science.gov (United States)

    Han, Guocheng; Wang, Xiaoying; Hamel, Jonathan; Zhu, Hongli; Sun, Runcang

    2016-12-01

    This work reported the green and facile fabrication of a versatile lignin-AuNP composite, which was readily and remotely encapsulated to form novel liquid marbles. The marbles can stay suspended in water, and show excellent photothermal conversion properties, as well as visual detection and adsorption towards Pb2+. More importantly, the marbles can simultaneously remotely detect and adsorb Pb2+ via co-precipitation by simply controlling the near infrared (NIR) irradiation. It is believed that the remotely-controllable NIR-responsive lignin-AuNPs liquid marble can be used in Pb2+-related reactions. The liquid marble can be placed in the system at the very beginning of the reaction and stably stays on the surface until the reaction has ended. After reacting, upon remote NIR irradiation, the liquid marble bursts to adsorb Pb2+, and the residual Pb2+ can be collected. This facile manipulation strategy does not use complicated nanostructures or sophisticated equipment, so it has potential applications for channel-free microfluidics, smart microreactors, microengines, and so on.

  5. Proton-induced fission at 190 MeV of W-nat, Au-197, Pb-nat, Pb-208, and Th-232

    NARCIS (Netherlands)

    Duijvestijn, MC; Koning, AJ; Beijers, JPM; Gastal, M; van Klinken, J; Ostendorf, RW

    1999-01-01

    Proton-induced fission at 190 MeV of W-nat, Au-197, Pb-nat, Pb-208, and Th-232 is studied by means of an innovative method based on activation analysis. The fission-product mass distribution is reconstructed from the fission-product yields, which are obtained from off-line observed gamma-ray spectra

  6. Enhanced Stability in Surface Plasmon Resonance Sensor Using Prism Coupler Based on Au/Bi2O3 Bilayer Film

    Directory of Open Access Journals (Sweden)

    Gaoyao Wei

    2013-05-01

    Full Text Available Surface Plasmon Resonance (SPR sensing has become a comprehensive utilized technology for detection, measurement and analysis in a wide spectrum of fields, ranging from biotechnology, environmental monitoring to food and drug monitoring. In this study, Au/Bi2O3 bilayer films with various layer thicknesses were deposited by thermal evaporation method on BK7 prism substrates and then post-annealing was conducted under ambient conditions. The adhesive strength of Au/Bi2O3 and Bi2O3/prism was measured with different layer thicknesses. Also, the SPR responses (reflectance vs. incident angle were investigated as a function of the thickness of Bi2O3 layer in the Kretschmann geometry using ethanol as dielectric. The results indicate that the adhesive strength between Au and prism was improved more than 3 times by introducing the Bi2O3 as buffer layer. And the SPR dips also demonstrate that SPR sensor based on Au/Bi2O3 bilayer films is practical, although the height of SPR dip with about 6nm Bi2O3 is approximately 4 times weaker than that of monolayer Au and the width (defined as FWHM broadens from 9° to 11°.

  7. The inhomogeneities of (Pb,Bi)2223 superconducting tapes and their detection

    Energy Technology Data Exchange (ETDEWEB)

    Leeuwen, S. van

    1999-05-01

    This thesis consists of two parts: first, the inhomogeneities that were observed in high temperature superconducting (Pb,Bi)2223 tapes were studied followed by the design of two rigs which were built to detect them. These investigations concentrated on (Pb,Bi)2223 phase high temperature superconducting tapes. Superconductors and their applications were briefly evaluated. It was found that high temperature superconductors have unique properties which cannot be duplicated by their counterparts. However, it was noted that there are significant improvements to be made before they can be commercially viable. An investigation was carried out into the variation of core density within cross sections and along lengths of (Pb,Bi)2223 tapes during fabrication. It was observed that rolling and thermal treatment brought about a non-uniform core density in both these aspects of tile tape. This was followed by an investigation into the effect of core density on the formation of the (Pb,Bi)2223 phase. It was shown that a high core density formed the (Pb,Bi)2223 phase at a slower rate than a lower core density under the thermal treatment. A high core density and a slow heating rate produced smaller 2212 grains at the end of the incubation period. Smaller 2212 grains were thought to be linked to the faster formation of the (Pb,B1)2223 phase. The highest Jc was from a high core density tape which had the smaller 2212 grains at the end of incubation period. Smaller 2212 grains were thought to aid a more homogeneous conversion to the (Pb,Bi)2223 phase. Alloy-sheathed (Pb,Bi)2223 superconducting tapes were produced in order to fabricate a more homogeneous core density. It was found that the alloy sheath (with an addition of 15% wt Ag in the precursor powder) changed the characteristics of the core in several ways: the formation of the (Pb,Bi)2223 phase was homogeneous across the thickness of the core, a smaller 2212 grain size was formed at the end of the incubation period and a higher

  8. Excitation function of squared speed-of-sound extracted from (net-)proton rapidity spectra in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC

    CERN Document Server

    Gao, Li-Na; Sun, Yan; Sun, Zhu; Lacey, Roy A

    2016-01-01

    Experimental results of the rapidity distributions of protons and net-protons (protons minus antiprotons) emitted in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions, measured by a few collaborations at the alternating gradient synchrotron (AGS), super proton synchrotron (SPS), and relativistic heavy ion collider (RHIC), are described by a revised Landau hydrodynamic model. The values of squared speed-of-sound parameter $c^2_s$ are then extracted from the rapidity distribution widths of (net-)protons. The excitation function of $c^2_s$ of the interacting system in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC is obtained to show a local minimum or softest point in the equation of state (EoS) at the center-of-mass energy per nucleon pair $\\sqrt{s_{NN}}=8.8$ GeV which confirms our previous result.

  9. Theoretical prediction of thermodynamic activities of liquid Au-Sn-X (X=Bi, Sb, Zn) solder systems

    Science.gov (United States)

    Awe, O. E.; Oshakuade, O. M.

    2017-02-01

    Molecular interaction volume model has been theoretically used to predict the thermodynamic activities of tin in Au-Sn-Bi and Au-Sn-Sb and the thermodynamic activity of zinc in Au-Sn-Zn at experimental temperatures 800 K, 873 K and 973 K, respectively. On the premise of agreement between the predicted and experimental values, we predicted the activities of the remaining two components in each of the three systems. This prediction was extended from three cross-sections to five cross-sections, and to temperature range 400-600 K, relevant for applications. Iso-activities were plotted. Results show that addition of tin reduces the tendency for chemical short range order in both Au-Sb and Au-Zn systems, while addition of gold and bismuth, respectively, reduce the tendency for chemical short range order in Sn-Sb and Au-Sn systems. Also, we found that, in the desired high-temperature region for applications, while a combination of chemical order and miscibility of components exist in both Au-Sn-Bi and Au-Sn-Zn systems, only chemical order exist in the Au-Sn-Sb system. Results, further show that increase in temperature reduces the phase separation tendency in Au-Sn-Bi system.

  10. Tensile testing of MANET II in flowing Pb-Bi alloy at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Glasbrenner, H. E-mail: heike.glasbrenner@psi.ch; Viol, D

    2002-11-01

    Experiments were carried out to study the influence of lead bismuth eutectic (LBE) on the tensile properties of the martensitic CrNiMoVNb steel named MANET II (Martensit for Next European Torus) considered as structural material for the first wall and blanket in fusion reactor conceptual design. In order to investigate a possible liquid metal embrittlement (LME) effect, tensile tests in flowing Pb-Bi at various temperatures (between 180 and 300 deg. C) were carried out. For comparison of the tensile test results achieved in Pb-Bi, tests were also carried out in the same facility but in an Ar atmosphere at the same temperature. After the tests, the fracture faces of the specimens were examined by SEM to analyse the fracture type (brittle or ductile). Additionally the ruptured specimens were longitudinally sectioned and analysed by metallurgical and SEM examinations.

  11. Ultrasonic studies of aluminium-substituted Bi(Pb)-2223 superconductors

    Indian Academy of Sciences (India)

    M B Solunke; P U Sharma; M P Pandy; V K Lakhani; K B Modi; P Venugopal Reddy; S S Shah

    2005-09-01

    The compositional dependence of elastic properties of Al3+ -substituted Bi(Pb)-2223 superconducting system with the general formula Bi1.7-AlPb0.3Sr2Ca2-Cu3O ( = 0.0, 0.1, 0.2 and 0.3) have been studied by means of ultrasonic pulse transmission (UPT) technique at 1 MHz (300 K). The elastic moduli of the specimens are computed and corrected to zero porosity. The observed variation of elastic constants with aluminium substitution has been explained on the basis of the strength of inter-atomic bonding. The applicability of heterogeneous metal mixture rule for estimating elastic constants and transition temperature has been tested.

  12. Half-metallic antiferromagnetism in double perovskite BiPbCrCuO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Ke-Chuan [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Wang, Y. K., E-mail: kant@ntnu.edu.tw [Center for General Education and Department of Physics, National Taiwan Normal University, Taipei 106, Taiwan (China)

    2015-05-07

    The electronic structure and magnetic properties of BiPbCrCuO{sub 6} double perovskite are investigated based on first-principles density functional calculations with generalized gradient approximation (GGA) and GGA incorporated with Coulomb correlation interaction U (GGA + U). The results suggest the half-metallic (HM) and antiferromagnetic (AFM) properties of BiPbCrCuO{sub 6} double perovskite. The HM-AFM property of the double perovskite is caused by the double-exchange mechanism between neighboring Cr{sup 5+}(t{sub 2g}{sup 1}↓) and Cu{sup 2+}(t{sub 2g}{sup 3}↑t{sub 2g}{sup 3}↓e{sub g}{sup 2}↑e{sub g}↓) via the intermediate O{sup 2−}(2s{sup 2}2p{sup 6}) ion.

  13. Hot isostatic pressure reaction treatment of Ag-sheathed Bi,Pb(2223) tapes

    Science.gov (United States)

    Beneduce, C.; Giannini, E.; Passerini, R.; Witz, G.; Seeber, B.; Flükiger, R.

    2002-08-01

    One of the parameters of power in tube (PIT) processed Bi,Pb(2223) tapes which still leaves room for improvement is the density of the filaments, presently reported to be around 80-90%. To some extent this can be addressed with optimised intermediate deformation methods, such as periodic pressing, but this solution is limited by the necessity to heal the damage after deformation. The synthesis of the Bi,Pb(2223) phase whilst applying a hot isostatic pressure (HIP) has been found to be an attractive alternative route to obtain higher ceramic density. In this work we compare the properties of tapes processed under various isostatic pressure up to 1000 bar. High pressure was found to fasten the kinetics of phase formation. SEM observation showed an increased density of the ceramic core in HIP processed tapes. 20 h annealing under 100 bar improved the critical current density by 30% compared to the standard first heat treatment in PIT process.

  14. Optical and structural properties of Pb S:Bi{sup 3+} nano crystals

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez P, R.; Portillo M, O.; Chaltel L, L.; Zamora T, M. [Universidad Autonoma de Puebla, Facultad de Ciencias Quimicas, Materials Science Laboratory, Apdo. Postal 1067, 72001 Puebla, Puebla (Mexico); Chavez P, M.; Palomino M, R., E-mail: osporti@yahoo.com.mx [Universidad Autonoma de Puebla, Facultad de Ciencias Fisicomatematicas, Posgrado en Optoelectronica, Apdo. Postal 1067, 72001 Puebla, Puebla (Mexico)

    2015-07-01

    We report here the growth of nanocrystalline Pb S thin films by chemical bath and the effects of doping on the structural and electronics properties as a function of Bi{sup 3+} concentration. Doping of such Pb S films with Bi{sup 3+} produces considerable optical and structural changes that have an effect on the material properties. The morphological changes of the layers were followed by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (Sem). X-ray diffraction spectra show growth of the zinc blende phase. The grain size for the undoped samples was found to be ∼ 32 nm, whereas that for the doped samples was 25-15 nm, thus confirming AFM and Sem results. A conspicuous shift for the forbidden band gap energy was observed by optical absorption from 1.2 eV for the undoped samples to a 1.7-2-0 eV range for the doped films. (Author)

  15. Muon Knight shift study of pseudogap state in underdoped (Bi,Pb)2201

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, M., E-mail: mmiya@post.kek.j [Department of Materials Structure Science, Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba, Ibaraki-Pref. 305-0801 (Japan); Kadono, R. [Department of Materials Structure Science, Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba, Ibaraki-Pref. 305-0801 (Japan); Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK-IMSS), 1-1 Oho, Tsukuba, Ibaraki-Pref. 305-0801 (Japan); Hiraishi, M.; Satoh, K.H. [Department of Materials Structure Science, Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba, Ibaraki-Pref. 305-0801 (Japan); Takeshita, S. [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK-IMSS), 1-1 Oho, Tsukuba, Ibaraki-Pref. 305-0801 (Japan); Koda, A. [Department of Materials Structure Science, Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba, Ibaraki-Pref. 305-0801 (Japan); Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK-IMSS), 1-1 Oho, Tsukuba, Ibaraki-Pref. 305-0801 (Japan); Fukunaga, Y.; Tanabe, Y.; Adachi, T.; Koike, Y. [Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

    2010-12-15

    We performed zero-field muon spin rotation/relaxation (ZF-{mu}SR) measurements on high-quality single-crystalline samples of Bi{sub 1.76}Pb{sub 0.35}Sr{sub 1.89}CuO{sub 6+{delta}} [(Bi,Pb)2201] over a wide doping region controlled by oxygen depletion ({delta}). We find that there is no static magnetic order above {approx}2 K in any of these samples including underdoped samples. The absence of slow antiferromagnetic fluctuation in the underdoped region allows reliable muon Knight shift measurements, which provides a direct evidence of reduced density of states at lower temperatures or 'pseudogap'.

  16. The crystal structure of kudriavite, (Cd,Pb)Bi2S4

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Makovicky, Emil

    2007-01-01

    The crystal structure of kudriavite, (Cd,Pb)Bi2S4, a new mineral species, was solved from single-crystal X-ray-diffraction data and refi ned to R = 4.9% (4.3% for a model with split mixed-cation sites). Lattice parameters are a 13.095(1), b 4.0032(3), c 14.711(1) Å, 115.59(1)°, V 695.6(1) Å3...

  17. Tensile tests on MANET II steel in circulating Pb-Bi eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Glasbrenner, H. E-mail: heike.glasbrenner@psi.ch; Groeschel, F.; Kirchner, T

    2003-05-15

    Off-beam tensile tests have been performed on MANET II steel in the eutectic Pb-55.5Bi (LBE) and Ar during commissioning of the LiSoR loop, an experimental liquid metal loop, which was developed to investigate the influence of Pb-Bi on possible structural materials under static load and irradiation. Test temperatures were 180-300 deg. C. MANET II (11% CrMoVNb steel) exhibits good swelling and creep resistance behaviour under irradiation up to around 500 deg. C. Good corrosion resistance of this material is expected due to the absence of the element Ni in the steel matrix which has a high solubility in LBE. All specimens showed a ductile fracture in Ar. In LBE a loss of ductility was observed at the test temperatures of 250 and 300 deg. C in comparison to the Ar samples. SEM analysis of the fracture surface of these specimens revealed a mixed mode, i.e. dimple and brittle fracture and penetration of Pb-Bi along the grain boundaries, which is a typical finding for liquid metal embrittlement.

  18. Processing Bi-Pb-Sr-Ca-Cu-O superconductors from amorphous state

    Science.gov (United States)

    Chiang, C. K.; Freiman, S. W.; Wong-Ng, W.; Hwang, N. M.; Shapiro, A. J.; Hill, M. D.; Cook, L. P.; Shull, R. D.; Swartzendruber, L. J.; Bennett, L. H.

    1990-01-01

    Researchers produced superconducting ceramics of the Bi-Pb-Sr-Ca-Cu-O system started from a glass. To form the glass, the mixed oxide powder was melted at 1200 C in air. The liquid was quenched rapidly by pouring it onto an aluminum plate and rapidly pressing with another plate. The quenched compound was in the form of black amorphous solid, whose x-ray powder pattern has no crystalline peaks. After heat treatment at high temperatures, the glass crystallized into a superconductor. The crystalline phases in the superconductor identified using x-ray diffraction patterns. These phases were that associated with the superconducting phases of T(sub c) = 80 K (Bi2Ca1Sr2Cu2Ox) and of T(sub c) = 110 K (Bi2Ca2Sr2Cu3Ox). The dc resistivity and the ac susceptibility of these superconductors were studied.

  19. Magnetoresistance and magnetothermopower properties of Bi/Ca/Co/O and Bi(Pb)/Ca/Co/O misfit layer cobaltites

    CERN Document Server

    Maignan, A; Hervieu, M; Michel, C; Pelloquin, D; Khomskii, D

    2003-01-01

    Two new compounds of the Bi/Ca/Co/O and Bi(Pb)/Ca/Co/O systems have been prepared. Their structure is built up from the intergrowth of four rock-salt-type layers and one [CoO sub 2 ] hexagonal layer. Both cobaltites exhibit large thermopower values (S sub 3 sub 0 sub 0 sub K approx 140 mu V K sup - sup 1), low resistivity values (rho sub 3 sub 0 sub 0 sub K = 40-60 m OMEGA cm) and small thermal conductivities (kappa sub 3 sub 0 sub 0 sub K approx 1 W K sup - sup 1 m sup - sup 1). Furthermore, these compounds exhibit a negative magnetoresistance, (MR = rho sub H - rho sub H sub sub 0 /rho sub H sub = sub 0), reaching, at 2.5 K, - 85% in 7 T for the Bi/Ca/Co/O misfit cobaltite. A large negative magnetothermopower is also found for these cobaltites in the same temperature range. A qualitative explanation of the observed behaviour is proposed.

  20. Study of the Neutron Deficient Pb and Bi Isotopes by Simultaneous Atomic- and Nuclear-Spectroscopy

    CERN Multimedia

    Kessler, T

    2002-01-01

    We propose to study systematically nuclear properties of the neutron deficient lead $^{183-189}$Pb, $^{191g}$Pb, $^{193g}$Pb and bismuth isotopes $^{188-200}$Bi by atomic spectroscopy with the ISOLDE resonance ionisation laser ion source (RILIS) combined with simultaneous nuclear spectroscopy at the detection set-up. The main focus is the determination of the mean square charge radii of $^{183-190}$Pb and $^{188-193}$Bi from which the influence of low-lying intruder states should become obvious. Also the nuclear spin and magnetic moments of ground-states and long-lived isomers will be determined unambiguously through evaluation of the hyperfine structure, and new isomers could be discovered. The decay properties of these nuclei can be measured by $\\alpha$-$\\gamma$ and $\\beta$-$\\gamma$ spectroscopy. With this data at hand, possible shape transitions around mid-shell at N$\\sim$104 will be studied. This data is crucial for the direct test of nuclear theory in the context of intruder state influence (e.g. energy ...

  1. Coherent view of crystal chemistry and ab initio analyses of Pb(II) and Bi(III) Lone Pair in square planar coordination

    OpenAIRE

    Matar, Samir F.; Galy, Jean

    2014-01-01

    The stereochemistry of 6s2 (E) lone pair of divalent Pb and trivalent Bi (PbII and BiIII designated by M*) in structurally related PbO, PbFX (X= Cl, Br, I), BiOX (X= F, Cl, Br, I) and Bi2NbO5F is rationalized. The lone pair LP presence determined by its sphere of influence E, equal to those of oxygen or fluorine anions, was settled by its center then giving M*-E directions and distances. Detailed description of structural features of both elements in the title compounds characterized by [PbEO...

  2. Influence of Pb-rich phases of precursor powder on microstructural evolution in the silver-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox superconducting tapes

    DEFF Research Database (Denmark)

    Chen, X.P.; Grivel, Jean-Claude; Li, M.Y.;

    2010-01-01

    The influence of Pb-rich phases of precursor powder on microstructural evolution during the first heat treatment of the silver-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox ((Bi,Pb)-2223/Ag) superconducting tapes was studied by means of in situ synchrotron X-ray diffraction. Three monofilament tapes were fabricat...

  3. Ternary reduced-graphene-oxide/Bi{sub 2}MoO{sub 6}/Au nanocomposites with enhanced photocatalytic activity under visible light

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Jinhong, E-mail: bijinhong@fzu.edu.cn [Department of Environmental Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108 (China); School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China); Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou, 350002 (China); Fang, Wei; Li, Li; Li, Xiaofen [Department of Environmental Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108 (China); Liu, Minghua; Liang, Shijing [Department of Environmental Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108 (China); Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou, 350002 (China); Zhang, Zizhong; He, Yunhui; Lin, Huaxiang; Wu, Ling [Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou, 350002 (China); Liu, Shengwei [School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China); Wong, Po Keung, E-mail: pkwong@cuhk.edu.hk [School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China)

    2015-11-15

    A novel ternary nanocomposite photocatalyst consisted of reduced-graphene-oxide (RGO), Bi{sub 2}MoO{sub 6} and plasmonic Au nanoparticles were successfully fabricated by multiple steps including a simple solvothermal process and photochemical reduction process. RGO/Bi{sub 2}MoO{sub 6}/Au was characterized by X-ray powder diffraction patterns, transmission electron microscopy, UV–vis diffuse reflectance spectra, Raman spectroscopy and X-ray photoelectron spectroscopy. In comparison with Bi{sub 2}MoO{sub 6}, RGO/Bi{sub 2}MoO{sub 6} and Au/Bi{sub 2}MoO{sub 6}, RGO/Bi{sub 2}MoO{sub 6}/Au exhibits an enhanced photocatalytic activity for decomposition of Rhodamine B under visible light. The separation efficiency of the photogenerated holes and electrons on Bi{sub 2}MoO{sub 6} is promoted by the combined effect of both RGO and Au in the ternary composite, and thus enhances photocatalytic activity. The scavenger study revealed that both hole and superoxide are the major reactive species for the photocatalytic degradation of Rhodamine B using RGO/Bi{sub 2}MoO{sub 6}/Au photocatalyst. - Graphical abstract: A novel ternary nanocomposite photocatalyst consisted of reduced-graphene-oxide (RGO), Bi{sub 2}MoO{sub 6} and plasmonic Au nanoparticles were successfully fabricated by multiple steps including a simple solvothermal process and photochemical reduction process. The resulted ternary nanocomposites greatly enhanced the visible light photocatalytic properties compared to Bi{sub 2}MoO{sub 6}, RGO/Bi{sub 2}MoO{sub 6} or Au/Bi{sub 2}MoO{sub 6} binary systems. The improved photocatalytic activity was mainly attributed to the synergistic effect of Au and RGO with better separation of the photogenerated holes and electrons, resulting from the surface plasmonic resonance and extra strong electron magnetic field of Au nanoparticles and the high electron conductivity of RGO. - Highlights: • The ternary nanocomposites RGO/Bi{sub 2}MoO{sub 6}/Au were constructed for the first time

  4. Bi-functional Au/FeS (Au/Co{sub 3}O{sub 4}) composite for in situ SERS monitoring and degradation of organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Shuzhen; Cai, Qian; Lu, Kailing; Liao, Fan, E-mail: fliao@suda.edu.cn; Shao, Mingwang, E-mail: mwshao@suda.edu.cn [Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University (China)

    2016-01-15

    The bi-functional Au/FeS (Au/Co{sub 3}O{sub 4}) composite was fabricated by in situ reducing Au nanoparticles onto the surface of FeS (Co{sub 3}O{sub 4}). The as-prepared FeS possessed a multi-structure composed of plenty of nanoplates, which were coated by Au nanoparticles with an average size of ∼47.5 nm. While the Co{sub 3}O{sub 4} showed a thin hexagonal sheet containing Au nanoparticles on its surface with an average size of ∼79.0 nm. Both the as-prepared Au/FeS and Au/Co{sub 3}O{sub 4} composites exhibited excellent SERS performance, capable of enhancing the Raman signals of R6G molecules with the enhancement factor up to 1.81 × 10{sup 6} and 7.60 × 10{sup 4}, respectively. Moreover, Au/FeS (Au/Co{sub 3}O{sub 4}) composite also has been verified to have intrinsic peroxidase-like activity, which could decompose H{sub 2}O{sub 2} into hydroxyl radicals and then degrade organic pollutants into small molecules. Therefore, SERS can be used to real-time and in situ monitoring the degradation process of R6G molecules, employing the Au/FeS (Au/Co{sub 3}O{sub 4}) composite both as SERS substrate and catalyst. Graphical abstract: SERS was used to real-time and in situ monitoring the degradation of R6G, employing the Au/FeS and Au/Co{sub 3}O{sub 4} composites both as SERS substrates and catalysts.

  5. Bi-and Au-Induced Reconstructions on GaAs(001)-2×4 Surface

    Institute of Scientific and Technical Information of China (English)

    TANG Zhe; YANG Shen-Yuan; JIANG Ying; WANG Wen-Xin; JIA Jin-Feng; XUE Qi-Sun; WANG En-Ge; WU Ke-Hui

    2008-01-01

    @@ Submonolayer Bi and Au adsorptions on the GaAs(001)-2×4 surface are investigated by scanning tunnelling microscopy, low energy electron diffraction and first-principles calculations. The 1 × 4 and 3 × 4 reconstructed surface induced by Bi and Au, respectively, are reveaied and their structural models are proposed based on experiments and first-principles calculations. Moreover, the validity of the recently proposed generalized electron counting (GEC) model [Phys. Rev. Lett. 97 (2006) 126103] is examined in detail by using the two surfaces. The GEC model perfectly explains the structural features, such as the characteristic short double-line structure in the Bi-1 × 4 surface and the 3× arrangement of four-atom Au clusters.

  6. Impedance Spectroscopic Studies of BiFeO3-Pb(ZrTi)O3 Nanocomposites

    Science.gov (United States)

    Choudhary, R. N. P.; Barik, Subrat K.; Katiyar, R. S.

    BiFeO3-Pb(ZrTi)O3 [i.e., (Bi1-xPbx)(Fe1-xZr0.6xTi0.4x)O3 (x = 0.15, 0.25, 0.40, 0.50)] nanocomposites were synthesized using mechanical activation followed by a solid-state reaction technique. The dielectric parameters (capacitance, dissipation factor D, impedance Z and phase angle Φ) of all the samples were measured in a wide range of frequencies (1 kHz-1 MHz) and temperatures (300-630 K) in air atmosphere using an impedance analyzer with low signal amplitude of 500 mV. Electrical properties of the compounds were studied using a complex impedance spectroscopy (CIS) technique. The frequency dependence of electrical data was analyzed in the framework of conductivity and modulus formalisms. AC conductivity spectrum obeys Jonscher's universal power law.

  7. High Curie temperature BiInO3-PbTiO3 films.

    Science.gov (United States)

    Lee, Sun Young; Wang, Wei; Trolier-McKinstry, Susan

    2014-06-14

    High Curie temperaturepiezoelectricthin films of xBiInO3-(1-x)PbTiO3 (x = 0.10, 0.15, 0.20, and 0.25) were prepared by pulsed laser deposition. It was found that the tetragonality of films decreased with increasing BI content. The dielectric constant and transverse piezoelectric coefficient (e31,f ) exhibit the highest values of 665 and -13.6 C/m(2) at x = 0.20. Rayleigh analyses were performed to identify the extrinsic contributions to dielectric nonlinearity with different x. The composition with x = 0.20 also exhibits the largest extrinsic contributions to dielectric nonlinearity. The Curie temperature (TC ) is increased with increasing x content from 558 to 633 °C; TC at x = 0.20 is about 584 °C.

  8. Twin Astir: An irradiation experiment in liquid Pb-Bi eutectic environment

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, J. van den [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium)], E-mail: jvdbosch@sckcen.be; Al Mazouzi, A.; Benoit, Ph.; Bosch, R.W.; Claes, W.; Smolders, B.; Schuurmans, P.; Abderrahim, H. Ait [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium)

    2008-06-30

    The Twin Astir irradiation program, currently under irradiation in the BR2 reactor at SCK.CEN is aimed at determining the separate and possibly synergetic effects of a liquid lead bismuth eutectic (LBE) environment and neutron irradiation. It will lead to a parameterisation of the key influencing factors on the mechanical properties of the candidate structural materials for the future experimental accelerator driven system (ADS). The experiment consists of six capsules containing mainly mini tensile samples and one capsule containing mini DCT's (disc shaped compact tension specimens). Three of the tensile containing capsules and half of the DCT containing capsule are filled each with approximately 20 ml of low oxygen (10{sup -6} wt%) LBE. To complete the filling of these capsules with LBE under controlled conditions a dedicated filling installation was constructed at SCK.CEN. The other three tensile containing capsules are subjected to PWR water conditions, in order to discriminate the effect of PbBi under irradiation from the effect of the irradiation itself. To extract the effect of the PbBi corrosion itself on the material properties, one of the capsules is undergoing the thermal cycles of the BR2 reactor without being subjected to irradiation. This results in a matrix of three irradiation doses in LBE (0, 1.5 and 2.5 dpa) and two environments (PbBi and PWR water conditions). Here we will present the detailed concept and the status of the Twin Astir project, describe the materials under irradiation and report on our experience with the licensing of the experiment.

  9. Improvement of superconducting properties of (Bi, Pb)-2223phase by TlF{sub 3} doping

    Energy Technology Data Exchange (ETDEWEB)

    Saoudel, A., E-mail: dca.saoudel@yahoo.fr [LEND, Faculty of Science and Technology, Med Seddik Benyahia University, 18000 Jijel (Algeria); Amira, A.; Mahamdioua, N.; Boudjadja, Y. [LEND, Faculty of Science and Technology, Med Seddik Benyahia University, 18000 Jijel (Algeria); Varilci, A.; Altintas, S.P.; Terzioglu, C. [Department of Physics, Faculty of Arts and Sciences, Abant Izzet Baysal University, 14280 Bolu (Turkey)

    2016-11-15

    In this work, the superconducting properties of thallium fluoride (TlF{sub 3})doped Bi{sub 1.8−x}Tl{sub x}Pb{sub 0.35}Sr{sub 2}Ca{sub 2Cu3}O{sub y}F{sub 3x}(x=0–0.15)compounds are presented. The X-ray diffraction analysis shows that the proportion of (Bi, Pb)-2223phase is higher than the secondary (Bi, Pb)-2212one in all samples and its highest value is about 82.74%for x=0.05. From the resistivity curves, the highest values of the onset critical transition temperature (T{sub c.on}), the offset critical transition temperature (T{sub c.off}) are seen for x=0.10. The calculation of activation energy (U{sub 0}) in the TAFF (thermally activation flux flow) region proves the positive effect of TlF{sub 3} doping on the dissipative behavior of energy near T{sub c.off}. Flux pinning strength is enhanced by increasing TlF{sub 3}content up to x=0.10, and decreased by the application of a magnetic field. The other superconducting parameters like T(H{sub c2}), T(H{sub irr}), ξ(0) and μ{sub 0}H{sub c2}(0) are also improved significantly by doping. The obtained results of Ac susceptibility measurements show that the onset temperature of diamagnetism is improved by TlF{sub 3} doping, in accordance with the resistivity results.

  10. Coordination chemistry of the sup 212 Pb/ sup 212 Bi nuclear transformation: Alpha-emitting radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Parks, N.J.; Harris, W.R.; Keen, C.L.; Cooper, S.R.

    1992-07-01

    Subdivisions of this project are: (a) the synthesis of prototypical thiolate and dithiocarbamate based hexacoordinate complexes, (b) radiochemical engineering for generation of no-carrier-added lead and bismuth radioelements, (c) the first isolation of bismuth-binding proteins from in vivo studies with cyclotron produced {sup 205/206}Bi tracer, and (d) initial development of transport mechanisms for the intracellular radiobiological study of alpha emitting bismuth, and (e) the initiation of chemical equilibrium studies and biochemical pathways with cyclotron-produced, no-carrier-added, {sup 203}Pb (T{sub 1/2} = 51 hr).

  11. Preparation of Bulky Bi(Pb)-Sr-Ca-Cu-O Superconductor by Magnetized Twin-Roll

    Science.gov (United States)

    Kawahara, Nobuaki; Kawabata, Sanemasa; Enami, Hiroyoshi; Shinohara, Toshiyuki; Hoshizaki, Hiroki; Hasegawa, Masashi; Asai, Shigeo; Imura, Toru

    1990-02-01

    A highly oriented (Bi, Pb)2Sr2Ca2Cu3Ox bulk superconductor has been prepared by magnetized twin-roll processing. In these bulks, plate-like crystal grains were highly oriented by a magnetic and mechanical force. The grain c-axes were parallel to the magnetic field and pressing directions. In fact, both critical current density (Jc) and orientation degree of the sample rolled under 2 T were higher than those of the sample rolled with no magnetic field. The magnetized twin-roll processing is effective not only in enhancing grain-orientation but also in packing to improve Jc.

  12. Unconventional Fermi surface spin patterns in the (Bi/Pb/Sb)/Ag(111) surface alloy

    Energy Technology Data Exchange (ETDEWEB)

    Meier, Fabian; Dil, Hugo [Physik Institut Universitaet Zuerich (Switzerland); Swiss Light Source PSI (Switzerland); Petrov, Vladimir [Physics Institute St Petersburg (Russian Federation); Patthey, Luc [Swiss Light Source PSI (Switzerland); Osterwalder, Juerg [Physik Institut Universitaet Zuerich (Switzerland)

    2009-07-01

    By a controllable change in the stoichiometry of the long range ordered mixed surface alloy (Bi/Pb/Sb)/Ag(111) the Rashba and Fermi energy can be tuned over a wide range. We show by spin and angle-resolved photoemission spectroscopy that the spin structure of the individual surface state bands remain unaffected despite the random intermixing of the adatoms. We further report on the observation of unconventional Fermi surface spin textures. These spin textures are found when the Fermi energy lies between the crossing point and the apex of the Rashba type Kramer's pair. The results will be discussed in the context of spin transport.

  13. Unusual Strong Incommensurate Modulation in a Tungsten-Bronze-Type Relaxor PbBiNb5O15.

    Science.gov (United States)

    Lin, Kun; Zhou, Zhengyang; Liu, Laijun; Ma, Hongqiang; Chen, Jun; Deng, Jinxia; Sun, Junliang; You, Li; Kasai, Hidetaka; Kato, Kenichi; Takata, Masaki; Xing, Xianran

    2015-10-28

    Pb- or Bi-based perovskite oxides have been widely studied and used because of their large ferroelectric polarization features induced by stereochemically active 6s(2) lone pair electrons. It is intriguing whether this effect could exist in other related systems. Herein, we designed and synthesized a mixed Pb and Bi A site polar compound, PbBiNb5O15, with the TTB framework. The as-synthesized material turns out to be a relaxor with weak macroscopic ferroelectricity but adopts strong local polarizations. What's more, unusual five orders of incommensurate satellite reflections with strong intensities were observed under the electron diffraction, suggesting that the modulation is highly developed with large amplitudes. The structural modulation was solved with a (3 + 1)D superspace group using high-resolution synchrotron radiation combined with anomalous dispersion X-ray diffraction technique to distinguish Pb from Bi. We show that the strong modulation mainly originates from lone-pair driven Pb(2+)-Bi(3+) ordering in the large pentagonal caves, which can suppress the local polarization in x-y plane in long ranges. Moreover, the as-synthesized ceramics display strong relaxor ferroelectric feature with transition temperature near room temperature and moderate dielectric properties, which could be functionalized to be electromechanical device materials.

  14. Influence of PbBi environment on the low-cycle fatigue behavior of SNS target container materials

    Energy Technology Data Exchange (ETDEWEB)

    Kalkhof, D.; Grosse, M. E-mail: micro.grosse@psi.ch

    2003-05-15

    The low-cycle fatigue (LCF) behavior of the stainless steel 316L and the 10.5Cr-steel Manet-II was investigated at 260 deg. C in air and in stagnant lead-bismuth (PbBi). At low-strain levels, the fatigue lives for 316L in PbBi and air were comparable. At total strain amplitudes of 0.50% and higher a weak influence of PbBi was observed. In contrast to 316L, the results of LCF tests for Manet-II in PbBi showed a significant reduction of lifetime for all applied strain amplitudes. In the worst case the cycle number to crack initiation was reduced by a factor of {approx}7 compared with the comparable test in air. For the low-strain amplitude of 0.30%, fatigue tests conducted at a frequency of 0.1 Hz had shorter fatigue lives than at a frequency of 1.0 Hz. For Manet-II the crack propagation in PbBi was much faster than in air, and failure immediate followed the formation of the first macroscopic crack.

  15. Electrochemical processing of high- Bi(Pb)–Sr–Ca–CuO thin films

    Indian Academy of Sciences (India)

    N V Desai; L A Ekal; D D Shivagan; S H Pawar

    2000-02-01

    Superconducting thin films of Bi(Pb)–Sr–Ca–CuO system were prepared by depositing the film onto silver substrate by d.c. electrodeposition technique with dimethyl sulphoxide bath in order to examine the effect of Pb addition to the BSCCO system. The films were deposited at the potential of – 0.8 V vs saturated calomel electrode (SCE) onto the silver substrate. The different preparative parameters such as deposition potential, deposition time were studied and optimized. These films were then oxidized electrochemically at room temperature in an alkaline (1 N KOH) solution, and also at 600°C temperature in an oxygen atmosphere. The films showed the superconducting behaviour, with values ranging between 85 K and 96 K, respectively.

  16. Energy Parameters of Interfacial Layers in Composite Systems: Graphene – (Si, Cu, Fe, Co, Au, Ag, Al, Ru, Hf, Pb and Semiconductor (Si,Ge – (Fe, Co, Cu, Al, Au, Cr, W, Pb

    Directory of Open Access Journals (Sweden)

    B.P. Koman

    2015-12-01

    Full Text Available On the basis of the non-equilibrium thermodynamics relations and the surface physics phenomena we calculate adhesion and energy parameters to characterize the interfacial interactions in graphene – (Si, Cu, Fe, Co, Au, Ag, Al, Ru, Hf, Pb and semiconductor (Si, Ge – (Fe, Co, Cu, Al, Au, Cr, W, Pb systems. We analyze trends of the interfacial energy, interfacial tension, work of adhesion and the energy of adhesive bonds on the contacting element’s atomic number in the periodic table and on the electronegativity difference of interacting elements. Thus, this work provides theoretical basis for the development of new composite materials.

  17. Superconductivity in Hg-Substituted BaPb0.75Bi0.25O3

    Institute of Scientific and Technical Information of China (English)

    Yong-Liang Chen; Ya-Jing Cui; Yong Zhang; Cui-Hua Cheng; Yong Zhao

    2008-01-01

    A series of Hg-doped BaPb0.75Bi0.25O3 with a nominal composition of BaPb0.75-xHgxBi0.25O3 (x=0 to 0.40 with 0.05 intervals) have been synthesized by solid-state reaction. These compounds exhibit a cubic perovskite-related structure with the lattice parameter being expanded by Hg doping. Superconducting transition temperature Tc and superconducting volume fraction are suppressed by Hg doping in the low doping level region (0≤ x ≤0.25). However, further increasing Hg content makes the superconductivity recovered at x>0.3. The superconductivity suppression in Hg-doped BaPb0.75Bi0.25O3 can be explained by the decrease of electron carrier concentration as well as the band- narrowing-induced electron localization.

  18. Thermoelectric Properties of Polycrystalline n-Type Pb5Bi6Se14

    Science.gov (United States)

    Sassi, S.; Candolfi, C.; Ohorodniichuk, V.; Gendarme, C.; Masschelein, P.; Dauscher, A.; Lenoir, B.

    2016-10-01

    Chalcogenides are currently receiving attention due to their interesting thermoelectric properties that stem from their complex crystal structures and semiconducting properties. Here, we report on the synthesis and measurements of the transport properties in a broad temperature range (2-723 K) of polycrystalline n-type Pb5Bi6Se14, a member of the homologous series (PbSe)5(Bi2Se3)3m (m = 1), to assess its thermoelectric potential and to shed light on the basic mechanisms governing the low-temperature transport. The anisotropic crystal structure gives rise to transport properties that differ on samples measured parallel or perpendicular to the pressing direction. The measurements show that this compound exhibits semiconducting-like properties with thermopower values that reach 250 μV K-1 at 723 K. The lattice thermal conductivity values are very low in the whole temperature range (˜0.5 W m-1 K-1) and close to the theoretical minimum thermal conductivity estimated from sound velocities. Thanks to this remarkable property, a peak ZT of 0.5 is achieved at 720 K.

  19. Thermoelectric Properties of Polycrystalline n-Type Pb5Bi6Se14

    Science.gov (United States)

    Sassi, S.; Candolfi, C.; Ohorodniichuk, V.; Gendarme, C.; Masschelein, P.; Dauscher, A.; Lenoir, B.

    2017-05-01

    Chalcogenides are currently receiving attention due to their interesting thermoelectric properties that stem from their complex crystal structures and semiconducting properties. Here, we report on the synthesis and measurements of the transport properties in a broad temperature range (2-723 K) of polycrystalline n-type Pb5Bi6Se14, a member of the homologous series (PbSe)5(Bi2Se3)3 m ( m = 1), to assess its thermoelectric potential and to shed light on the basic mechanisms governing the low-temperature transport. The anisotropic crystal structure gives rise to transport properties that differ on samples measured parallel or perpendicular to the pressing direction. The measurements show that this compound exhibits semiconducting-like properties with thermopower values that reach 250 μV K-1 at 723 K. The lattice thermal conductivity values are very low in the whole temperature range (˜0.5 W m-1 K-1) and close to the theoretical minimum thermal conductivity estimated from sound velocities. Thanks to this remarkable property, a peak ZT of 0.5 is achieved at 720 K.

  20. Correlation between morphology, electron band structure, and resistivity of Pb atomic chains on the Si(5 5 3)-Au surface.

    Science.gov (United States)

    Jałochowski, M; Kwapiński, T; Łukasik, P; Nita, P; Kopciuszyński, M

    2016-07-20

    Structural and electron transport properties of multiple Pb atomic chains fabricated on the Si(5 5 3)-Au surface are investigated using scanning tunneling spectroscopy, reflection high electron energy diffraction, angular resolved photoemission electron spectroscopy and in situ electrical resistance. The study shows that Pb atomic chains growth modulates the electron band structure of pristine Si(5 5 3)-Au surface and hence changes its sheet resistivity. Strong correlation between chains morphology, electron band structure and electron transport properties is found. To explain experimental findings a theoretical tight-binding model of multiple atomic chains interacting on effective substrate is proposed.

  1. Combined ARPES and STM study of Pb/Au(111) Moiré structure: One overlayer, two symmetries

    Science.gov (United States)

    Crepaldi, A.; Pons, S.; Frantzeskakis, E.; Calleja, F.; Etzkorn, M.; Seitsonen, A. P.; Kern, K.; Brune, H.; Grioni, M.

    2013-03-01

    The structural and electronic properties of a Pb monolayer (ML) grown on Au(111) are investigated by scanning tunneling microscopy (STM) and angle resolved photoelectron spectroscopy (ARPES). We find an incommensurate Moiré structure with an approximate (5.77×5.77) R21.5∘ unit cell, and two rotational domains. We observe three Pb-derived bands of p orbital character. The symmetry properties and sharpness of their Fermi surfaces are remarkably different. They reflect the different degrees of hybridization of these bands with the Au(111) bulk continuum.

  2. Crystal structures of a pentavalent bismuthate, SrBi2O6 and a lead bismuth oxide (Pb1/3Bi2/3O1.4

    Directory of Open Access Journals (Sweden)

    Nobuhiro Kumada

    2014-06-01

    Full Text Available The crystal structures of a pentavalent bismuthate, SrBi2O6 with the PbSb2O6-type structure and a lead bismuth oxide, (Pb1/3Bi2/3O1.4 with the fluorite-type structure were refined by using neutron diffraction data. The final R-factors were Rwp = 4.49, Rp = 3.46, RI = 4.50 and RF = 1.70% for SrBi2O6 and Rwp = 5.04, Rp = 3.93, RI = 5.47 and RF = 4.26% for (Pb1/3Bi2/3O1.4. SrBi2O6 prepared from NaBiO3·1.4H2O is the first example of the bismuthate with the PbSb2O6-type structure. The fluorite-type lead bismuth oxide, (Pb1/3Bi2/3O1.4 was obtained by heating the PbSb2O6-type lead bismuthate, PbBi2O5.9·H2O which was prepared also from NaBiO3·1.4H2O.

  3. High Thermoelectric Properties of PbTe Doped with Bi2Te3 and Sb2Te3

    Institute of Scientific and Technical Information of China (English)

    ZHU Pin-Wen; IMAI Yoshio; ISODA Yukihiro; SHINOHARA Yoshikazi; JIA Xiao-Peng; ZOU Guang-Tian

    2005-01-01

    @@ The composition-dependent thermoelectric properties of lead telluride (PbTe) doped with bismuth telluride(Bi2Te3), antimony telluride (Sb2Te3) and (BiSb)2Te3 have been studied at room temperature. All the samples exhibit small thermal conductivity. The figures of merit, 7.63, 1.03 and 8.97 × 10-4, have been obtained in PbTe with these dopants, respectively. These values are several times higher than those of PbTe containing other dopants with small grain sizes. The high thermoelectric performance is explained by electronic topological transition induced by alloying. The results indicate that these dopants are effective to enhance the thermoelectric performance of Pb Te.

  4. Pb- and Sm-doping effects on the vortex dynamics in Bi4O4S3 superconductor

    Science.gov (United States)

    Xie, L.; Tie, X. Y.; Zhang, H. G.

    2017-01-01

    Polycrystalline samples of Bi4O4S3, Bi3.94Pb0.06O4S3, and Bi3.94Sm0.06O4S3 were synthesized using a conventional solid-state reaction method. The vortex dynamics of these samples are studied and compared through measuring the critical current density (Jc) and magnetic relaxation. The estimated Jc value of three samples at temperature 2 K decreases with doping Pb and Sm elements due to the depression of the superconductivity. The normalized pinning force response with reduced field follows the Kramer scaling law f (h )∝ hp(1-h ) q , and the maximum of the reduced field (hmax) is observed at 0.31, 0.24, and 0.18 for Bi4O4S3, Bi3.94Pb0.06O4S3, and Bi3.94Sm0.06O4S3, respectively, indicating the presence of both surface and point pinning centers in these samples. The barrier energy estimated by the magnetic relaxation data depends on the field as a negative power law U0∝Hn and the magnetic relaxation rate S exhibits a considerable monotonic increase with magnetic field, which corroborates a plastic nature of the creep vortex dynamics in these compounds.

  5. De Bièvre à Brisset : du calembour de salon au calembour cosmique

    OpenAIRE

    Champion, Bernard

    2016-01-01

    LE CALEMBOUR FACE À LA RÉVOLUTION À l’aube et au crépuscule du xixe siècle, qui s’est voulu le siècle de la raison triomphante, deux figures littéraires, François-Georges Maréchal, marquis de Bièvre, et Jean-Pierre Brisset, « prince des penseurs », se signalent par un usage irraisonné et déraisonnable de la langue qui s’épanouit dans cette figure qu’on appelle le calembour. L’étymologie du mot calembour est discutée. Sa description en revanche ne pose pas spécialement question : C’est un redo...

  6. Mechanism of interaction relation between the rare-earth element Ce and impurity elements Pb and Bi in Ag-based filler metal

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The mechanism of interaction relation between the rare-earth element Ce and elements Pb and Bi in Ag-based filler metal has been studied. The results show that the compounds CePb and CeBi with high melting point can be easily produced between these three elements in the filler metal, which greatly limited the formation of the isolated phase Pb or Bi and also eliminated the bad effect of impurity elements Pb and Bi on the spreading property of Ag-based filler metal. The metallurgical and quantum-mechanical bond formation analysis show that a strong chemical affinity was existed between the rare-earth element Ce and impurity elements Pb and Bi, which was proved by the XRD analysis results.

  7. Effect of thermosolutal convection on the solid-liquid interface in Pb-Au alloy

    Science.gov (United States)

    Tewari, S. N.; Chopra, M. A.

    1990-01-01

    Liquid-solid interface distortion in the region of primary dendrite tips has been investigated in directionally solidified Pb-8 wt pct Au alloy. The distortions are caused by thermosolutal convection despite choice of growth conditions which should have been thermally and solutally stabilizing. The convection produces clustering of primary dendrites on a plane perpendicular to the growth direction. It produces a mushy zone, where the primary dendrites do not protrude with a uniform length, across the specimen cross section, resulting in large macrosegregation in the transverse direction. However, little macrosegregation is observed along the growth direction. The mushy zone, with uneven dendrite lengths, forms in the beginning of directional solidification. Its shape and dendrite distribution do not show much change during subsequent solidification. Tip morphologies of primary dendrites, within the dendrite clusters, appear to follow the morphological stability relationship.

  8. Breakup mechanisms for 7Li + 197Au, 204Pb systems at sub-barrier energies

    Directory of Open Access Journals (Sweden)

    Luong D.H.

    2013-12-01

    Full Text Available Coincidence measurements of breakup fragments were carried out for the 7Li + 197Au and 204Pb systems at sub-barrier energies. The mechanisms triggering breakup, and time-scales of each process, were identified through the reaction Q-values and the relative energy of the breakup fragments. Binary breakup of 7Li were found to be predominantly triggered by nucleon transfer, with p-pickup leading to 8Be → α + α decay being the preferred breakup mode. From the time-scales of each process, the coincidence yields were separated into prompt and delayed components, allowing the identification of breakup process important in the suppression of complete fusion of 7Li at above-barrier energies.

  9. Geology and mineralogy of the Au-As (Ag-Pb-Zn-Cu-Sb polymetallic deposit of Valiña-Azúmara (Lugo, NW Spain

    Directory of Open Access Journals (Sweden)

    Martínez-Abad, I.

    2015-12-01

    Full Text Available Valiña-Azúmara is a polymetallic Au-As (Ag-Pb-Zn-Cu-Sb deposit, located in the province of Lugo (NW Spain, that was mined for arsenic at the beginning of the 20th century. The mineralization is hosted in a Variscan thrust fault with a dip direction of N247-261ºE, and N-S and NE-SW Late-Variscan faults. These structures are hosted in black slates, Cambrian in age. To a lesser extent, the mineralization also occurs disseminated within narrow, weakly silicified and sericited selvages. Mineralization is divided into two hypogene stages. The first consists of quartz, calcite, rutile, sericite, arsenopyrite and pyrite. Two types of pyrite (Py-I and Py-II are defined according to their chemical and textural characteristics. Py-II occurs as overgrowth of previous Py-I crystals. Py-II is As-rich (≤1.7 wt.% and often contains traces of Te, Zn, Cu, Bi, Sb and Au. The mineralized drill core sections show a significant correlation between Au and As. This is due to Au occurring as invisible Au within the Py-II grains, with contents of up to 176 ppm. The Au/As ratios of Py-II indicate that Au was deposited as Au1+, as solid solution within the pyrite structure. The second stage of mineralization is enriched in Ag-Pb-Zn-Cu-Sb, replacing the first stage, and consists of quartz, calcite, chlorite, sphalerite, jamesonite, Ag-rich tetrahedrite, freibergite, chalcopyrite, pyrrhotite and galena. Although jamesonite shows traces of Ag, the Cu-Ag sulfosalts are the main carriers of the Ag mineralization in the deposit, with contents that vary from 13.7 to 23.9 wt.% of Ag. In the most superficial levels of the area, secondary Fe oxide and hydroxide, scorodite and anglesite developed due to the oxidation of the ore.Valiña-Azúmara es un yacimiento filoniano de Au-As (Ag-Pb-Zn-Cu-Sb situado en la provincia de Lugo (NO España, que fue explotado por arsénico a principios del siglo XX. La mineralización se encuentra encajada en un cabalgamiento Varisco de direcci

  10. Stopping Power of Al, Cu, Ag, Au, Pb, and U for 5-18-MeV Protons and Deuterons

    DEFF Research Database (Denmark)

    Sørensen, H.; Andersen, Hans Henrik

    1973-01-01

    High energy protons and deuterons of energies between 9 and 18 MeV have been used to extend earlier measurements of the stopping power of Al, Cu, Ag and Au and the stopping powers of Pb and U in the range 5-18 MeV have been determined for the first time. Mean excitation potentials have been...

  11. Compatibility of T91 steel with liquid Pb-Bi eutectic alloy at 450 oC

    Directory of Open Access Journals (Sweden)

    Zhang Yutuo

    2014-05-01

    Full Text Available Pb-Bi eutectic alloy has been receiving increasing attention as a heavy liquid metal coolant in accelerator driven systems and Generation IV fission reactors. Compatibility of structural materials with liquid Pb-Bi eutectic alloy at high temperature is one of the issues concerned. In the present study, corrosion tests of T91 steel in stagnant Pb-Bi eutectic alloy in saturated oxygen condition at 450 篊 were carried out. After experiments, the thickness and compositional profile of the oxide layer on the specimen were analyzed using SEM and EDX. Analysis results show that the thickness of the oxide layer increases as the exposure time increases from 500 h to 1,000 h. The thickness of the oxide layer remains almost unchanged at 15 to 16 mm from 1,000 to 1,500 h. Formation of a thick and protective oxide layer at 450 oC prevents the penetration of liquid Pb-Bi eutectic alloy into the matrix of the T91 steel.

  12. Solvothermal preparation and thermoelectric properties of quasi-binary Sn(Pb)Te-Bi2Te3 compounds

    Institute of Scientific and Technical Information of China (English)

    周西松; 邓元; 韦国丹; 刘静; 南策文

    2003-01-01

    Bulk samples of quasi-binary compounds in the Sn(Pb)Te-Bi2Te3 system were prepared by solvothermal method followed by a sintering procedure of compacted pellets. The formation mechanism of the precursor powders, microstructure and thermoelectric properties of the final bulk samples were studied.

  13. Fluctuation Induced Conductivity Studies of 100 MeV Oxygen Ion Irradiated Pb Doped Bi-2223 Superconductors

    NARCIS (Netherlands)

    Banerjee, Tamalika; Kumar, Ravi; Kanjilal, D.; Ramasamy, S.

    2000-01-01

    We report on 100 MeV oxygen ion irradiation in Pb doped Bi-2223 superconductors. Resistivity measurements reveal that both grains as well as the grain boundaries are affected by such irradiation. An analysis of the excess conductivity has been made within the framework of Aslamazov-Larkin (AL) and L

  14. Nano-Channels Early Formation Investigation on Stainless Steel 316Ti after Immersion in Molten Pb-Bi

    Directory of Open Access Journals (Sweden)

    Abu Khalid Rivai

    2017-04-01

    Full Text Available Pb-Bi (lead-bismuth eutectic-LBE is a coolant of one of main candidates for the future nuclear reactor in the world (Generation IV reactors i.e. LFR (Lead alloy-cooled Fast Reactor, and also a spallation target material for ADS (Accelerator Driven Transmutation System. However, the development of fuel cladding and structural materials in LBE environment, especially at high temperature, is a critical issue for the deployment of LFR and ADS. This is because of the corrosive characteristic of LBE to metals as constituent materials of fuel cladding and structural of the reactors. In this study, corrosion test of a high-chromium austenitic steel i.e. SS316Ti in liquid Pb-Bi at 550ºC has been carried out for about 300 hours. The characterization using SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscope showed that an iron oxide as the outer layer and a chromium oxide as the inner layer on the surface of the specimen were formed which protected the steel specimen from corrosion and dissolution attack of Pb-Bi. However, small amount of Pb-Bi could penetrate into the iron oxide layer through ultra-thin channels. Atomic Force Microscopy (AFM was employed to investigate the phenomena of the channels formation. The results of the nano-scale investigation showed clearly the formation of the channels.

  15. Synthesis, Structural and Optical Investigations of (Pb, BiTiO3 Borosilicate Glasses

    Directory of Open Access Journals (Sweden)

    Chandkiram Gautam

    2014-01-01

    Full Text Available A new series of lead bismuth titanate borosilicate glasses with addition of one percent lanthanum oxide have been synthesized using melt-quench technique. X-ray diffraction patterns have been recorded to confirm the amorphous nature of the prepared glass samples. The synthesized glasses have been characterized by using various spectroscopic techniques such as UV-visible, infrared, and Raman spectroscopy. UV-visible measurements were recorded in the wavelength range from 200 to 1100 nm whereas IR and Raman spectroscopic measurements were recorded over a continuous wavenumber range from 400 to 5000 cm−1 and 1000 to 2000 cm−1 respectively. The different absorption peaks/bands were formed in IR spectral patterns. The spectral bands appear towards the lower wavenumber sides due to the Bi and Pb, content while the bands appear towards the higher wavenumber sides due to the formation of diborate and triborate network units.

  16. Development of a liquid Pb-Bi target for high-power ISOL facilities

    Energy Technology Data Exchange (ETDEWEB)

    Houngbo, D., E-mail: dhoungbo@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Department of Flow, Heat and Combustion Mechanics, Ghent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium); Bernardes, A.P. [CERN, 1211 Geneva 23 (Switzerland); David, J.C. [CEA/Saclay, 91191 Gif-sur-Yvette cedex (France); Delonca, M. [CERN, 1211 Geneva 23 (Switzerland); IRTES-M3M & IRTES-LERMPS, Université de Technologie de Belfort-Montbeliard, 90010 Belfort Cedex (France); Kravalis, K. [Institute of Physics of University of Latvia (IPUL), 32 Miera iela, Salaspils LV-2169 (Latvia); Lahiri, S. [Saha Institute of Nuclear Physics 1/AF Bidhannagar, Kolkata 700064 (India); Losito, R.; Maglioni, C. [CERN, 1211 Geneva 23 (Switzerland); Marchix, A. [CEA/Saclay, 91191 Gif-sur-Yvette cedex (France); Mendonca, T.M. [CERN, 1211 Geneva 23 (Switzerland); Popescu, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Schumann, D. [Paul Scherrer Institute (PSI), 5232 Villigen PSI (Switzerland); Schuurmans, P. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Stora, T.; Vollaire, J. [CERN, 1211 Geneva 23 (Switzerland); Vierendeels, J. [Department of Flow, Heat and Combustion Mechanics, Ghent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium)

    2016-06-01

    This paper describes some R&D activities conducted in support of the design and safe operation of a high-power liquid Pb-Bi target within the LIEBE (Liquid Eutectic Lead Bismuth Loop Target for EURISOL) project. The target material is lead bismuth eutectic (LBE) which also acts as a primary coolant. As a consequence of interaction of the highly pulsed 1.4-GeV protons at ISOLDE with the target, heat powers of the order of 2 GW would be instantaneously deposited in the target during a bunch. Considerable R&D effort is thus required to demonstrate its continued coolability and structural integrity. This paper mainly reports on the conjugate flow (CFD) and heat deposition (Monte Carlo) calculations, not accounting for Fluid–Structure Interactions.

  17. Out-of-pile chemical compatibility of Pb-Bi eutectic alloy with graphite

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, A.K.; Bhagat, R.K.; Jarvis, T.; Majumdar, S. [Radiometallurgy Div., Bhabha Atomic Research Centre, Mumbai (India); Laik, A.; Kale, G.B. [Material Science Div., Bhabha Atomic Research Centre, Mumbai (India); Kamath, H.S. [Nuclear Fuels Group, Bhabha Atomic Research Centre, Mumbai (India)

    2006-06-15

    Lead Bismuth eutectic alloy (Pb: 55.5 wt.%, Bi: 44.5 wt.%) is a potential candidate coolant material for high-temperature reactors because of its low melting point (124 C), high thermal conductivity, heat capacity, and better neutronic properties. Out-of-pile chemical compatibility studies of this coolant with graphite (coolant channel) have been carried out by isothermal annealing of the liquid alloy in a graphite crucible at 800, 900, 1000, and 1100 C for times ranging from 100 h to 1000 h. Formation of a reaction layer is observed. The growth rate of the reaction layer follows a parabolic law. Reaction layer thicknesses of 61.3 {mu}m and 121 {mu}m are estimated from the growth rate vs. time relation after 1 year and 5 years respectively. The growth of the reaction layer is diffusion-controlled and the activation energy of the reaction is estimated to be 100 KJ/mol. (orig.)

  18. Structural and low temperature transport properties of PbBi thin films fabricated by rapid solidification technique

    Science.gov (United States)

    Kuru, Mehmet; Ongun, Erhan; Esad Ozmetin, Ali

    2017-06-01

    In this work, 500 nm thick superconducting α-phase PbBi thin-films were grown by thermal evaporation and quench-condensation mechanism in a vacuum chamber. Thermally-evaporated lead-bismuth vapor condensed on the silicon substrate which was cooled to 77 K by liquid nitrogen (LN2). Titanium-sublimation and a homemade LN2 cold-trap station were utilized to further improve the vacuum conditions. Structural and elemental analyses were conducted using scanning electron microscopy and energy dispersive x-ray spectroscopy techniques. The alloy content of the resulting PbBi film (78.22 at% Pb and 21.78 at% Bi) was found similar to that of the source alloy (82 at% Pb and 18 at% Bi) as the vapor pressure of bismuth lies close to that of lead. To reveal the transport characteristics of superconducting PbBi film, low temperature DC transport measurements were conducted by means of a four-probe method in a closed cycle dry cryostat cryogenics system. It was revealed that the superconductivity transition temperature of PbBi film decreased from 7.74 K to 5.95 K under increasing H-fields from 0 kOe to 7 kOe, respectively. Based on the R-T measurements, the electrical resistivity of quench-condensed PbBi film was calculated at different temperatures of 300 K, 77 K and 7.74 K, which were found as 9.11× {{10}-7} \\text{ohm}\\cdot \\text{m} , 4.43× {{10}-7} \\text{ohm}\\cdot \\text{m} and 1.95× {{10}-7} \\text{ohm}\\cdot \\text{m} , respectively. The residual resistance ratio value, which gives a rough estimation about the quality and performance of the superconducting film, was calculated as 4.65 indicating a reasonably quality film formation.

  19. Highly efficient and stable Au/Bi2MoO6/Bi2WO6 heterostructure with enhanced photocatalytic activity for NO gas removal under visible light irradiation

    Science.gov (United States)

    Jia, Jia; Du, Xiao; Liu, Enzhou; Wan, Jun; Pan, Chao; Ma, Yongning; Hu, Xiaoyun; Fan, Jun

    2017-04-01

    The ternary composite photocatalyst Au/Bi2MoO6/Bi2WO6 has been successfully synthesized by a facile hydrothermal process and microwave-assisted chemical reduction method for the first time. A series of characterization results reveal that Au nanoparticles are uniformly dispersed on the surface of Bi2MoO6/Bi2WO6 microspheres. The unique photocatalytic performance of the novel composite material is evaluated by the photocatalytic removal of NO gas at ppb levels under visible light irradiation. The photocatalytic removal rate of NO gas in the presence of Au/Bi2MoO6/Bi2WO6 sample is the highest, which directly attributes to the effective separation of photoinduced charge carriers through the formation of the heterojunction and the Schottky junction at the interface between Au nanoparticles and Bi2MoO6 or Bi2WO6. Additionally, it is indicated that the h + and \\centerdot \\text{O}2- play indispensable role in photocatalytic process by free radicals trapping experiments and the oxidation products of NO gas on the surface of the catalysts are nitrate by drawing the standard curve of total N content in nitrate. Meanwhile, a possible mechanism for the photocatalytic activity enhancement of the Au/Bi2MoO6/Bi2WO6 composites is proposed. These results demonstrate that the Au/Bi2MoO6/Bi2WO6 photocatalyst is a promising candidate for indoor air purification under solar light irradiation.

  20. MYRRHA, a Pb-Bi experimental ADS: specific approach to radiation protection aspects.

    Science.gov (United States)

    Abderrahim, H Aït; Aoust, Th; Malambu, E; Sobolev, V; Van Tichelen, K; De Bruyn, D; Maes, D; Haeck, W; Van den Eynde, G

    2005-01-01

    Since 1998, SCK*CEN, in partnership with IBA s.a. and many European research laboratories, is designing a multipurpose accelerator driven system (ADS) for Research and Development (R&D) applications-MYRRHA-and is conducting an associated R&D support programme. MYRRHA is an ADS under development at Mol in Belgium and is aiming to serve as a basis for the European experimental ADS to provide protons and neutrons for various R&D applications. It consists of a proton accelerator delivering a 350 MeV x 5 mA proton beam to a liquid Pb-Bi spallation target that in turn couples to a Pb-Bi cooled, subcritical fast core. In the first stage, the project focuses mainly on demonstration of the ADS concept, safety research on sub-critical systems and nuclear waste transmutation studies. In a later stage, the device will also be dedicated to research on structural materials, nuclear fuel, liquid metal technology and associated aspects, and on sub-critical reactor physics. Subsequently, it will be used for research on applications such as radioisotope production. A first preliminary conceptual design file of MYRRHA was completed by the end of 2001 and has been reviewed by an International Technical Guidance Committee, which concluded that there are no show stoppers in the project and even though some topics such as the safety studies and the fuel qualification need to be addressed more deeply before concluding it. In this paper, we are reporting on the state-of-the art of the MYRRHA project at the beginning of 2004 and in particular on the radiation shielding assessment and the radiation protection particular aspects through a remote handling operation approach in order to minimise the personnel exposure to radiation.

  1. Structural, dielectric, and ferroelectric properties of the (1-x)PbTiO₃-xBiAlO₃ solid solution.

    Science.gov (United States)

    Yu, Huichun; Ren, Wei; Ye, Zuo-Guang

    2010-10-01

    Ferroelectric ceramics derived from the solid solution of (1-x)PbTiO₃-xBiAlO₃ (x = 0, 0.05, 0.10, 0.15, and 0.18) have been synthesized by solid-state reactions. A pure perovskite phase is formed for 0 ≤ x ≤ 0.15. The tetragonality (c/a) of the solid solution decreases with the increasing amount of BiAlO₃. Scanning electron microscopic images reveal a microstructure with a fine grain size of less than 1 μm for the solid solution ceramics (x ≥ 0.05). Compared with pure PbTiOPbTiO₃ ceramics whose high conductivity and poor densification were harmful to their dielectric performance, the ceramics of (1-x)PbTiO₃-xBiAlO₃ are well-densified (with a relative density of up to 93%) and their dielectric and ferroelectric properties are significantly improved with the addition of BiAlO₃, exhibiting reduced dielectric losses, well-developed P-E hysteresis loops (for x = 0.05, 0.10, and 0.15) and a high remnant polarization (P(r)) of 64 μC/cm² (for x = 0.15).

  2. Development of heat resistant Pb-free joints by TLPS process of Ag and Sn-Bi-Ag alloy powders

    Directory of Open Access Journals (Sweden)

    Ohnuma I.

    2012-01-01

    Full Text Available TLPS (Transient Liquid Phase Sintering process is a candidate method of heat-resistant bonding, which makes use of the reaction between low-melting temperature powder of Sn-Bi base alloys and reactive powder of Ag. During heat treatment above the melting temperature of a Sn-Bi base alloy, the molten Sn-Bi reacts rapidly with solid Ag particles, which results in the formation of heat-resistant intermetallic compound (IMC. In this study, the TLPS properties between Sn-17Bi-1Ag (at.% powder with its liquidus temperature of 200°C and pure Ag powder were investigated. During differential scanning calorimetry (DSC measurement, an exothermic reaction and an endothermic reaction occurred, which correspond to the formation of the e-Ag3Sn IMC phase and the melting of the Sn-17Bi-1Ag alloy, respectively. After the overall measurement, the obtained reactant consists of the Ag3Sn-IMC and Bi-rich phases, both of which start melting above 250°C, with a small amount of the residual Sn-Bi eutectic phase. These results suggest that the TLPS process can be applied for Pb-free heatresistant bonding.

  3. Crystal Structure and Thermoelectric Properties of the (7,7)L Lillianite Homologue Pb6Bi2Se9.

    Science.gov (United States)

    Casamento, Joseph; Lopez, Juan S; Moroz, Nicholas A; Olvera, Alan; Djieutedjeu, Honore; Page, Alexander; Uher, Ctirad; Poudeu, Pierre F P

    2017-01-03

    Pb6Bi2Se9, the selenium analogue of heyrovsyite, crystallizes in the orthorhombic space group Cmcm (#63) with a = 4.257(1) Å, b = 14.105(3) Å, and c = 32.412(7) Å at 300 K. Its crystal structure consists of two NaCl-type layers, A and B, with equal thickness, N1 = N2 = 7, where N is the number of edge-sharing [Pb/Bi]Se6 octahedra along the central diagonal. In the crystal structure, adjacent layers are arranged along the c-axis such that bridging bicapped trigonal prisms, PbSe8, are located on a pseudomirror plane parallel to (001). Therefore, Pb6Bi2Se9 corresponds to a (7,7)L member of the lillianite homologous series. Electronic transport measurements indicate that the compound is a heavily doped narrow band gap n-type semiconductor, with electrical conductivity and thermopower values of 350 S/cm and -53 μV/K at 300 K. Interestingly, the compound exhibits a moderately low thermal conductivity, ∼1.1 W/mK, in the whole temperature range, owing to its complex crystal structure, which enables strong phonon scattering at the twin boundaries between adjacent NaCl-type layers A and B. The dimensionless figure of merit, ZT, increases with temperature to 0.25 at 673 K.

  4. The equation of state of Bi and cross-checking of Au and Pt scales to megabar pressure

    CERN Document Server

    Akahama, Y; Singh, A K

    2002-01-01

    By means of x-ray diffraction experiments using a synchrotron radiation source, the equation of state (EOS) of body-centred cubic Bi has been investigated over a range of multimegabar pressure up to 222 GPa on the basis of the Pt pressure scale and it is proposed as an internal pressure standard over a range of megabar pressures. Pressure scales of the EOS of Au and Pt were cross-checked and the accuracy of the scales is discussed.

  5. Fission fragment angular distributions in proton-induced fission of 209 Bi(p,t and 197 Au(p,f

    Directory of Open Access Journals (Sweden)

    S. S.

    2001-12-01

    Full Text Available   The fission fragment angular distributions have been measured for proton-induced fission of 209Bi and 197Au nuclei using surface barrier detectors at several energies between 25 MeV and 30 MeV. The experimental anisotropies are found to be in agreement with the predictions of the Standard Saddle-Point Statistical Model (SSPSM. The fission cross sections of 209Bi 197Au nuclei were also measured and compared with the previous works.

  6. Determination of Te, Bi, Ni, Sb and Au by X-ray fluorescence spectrometry following electroenrichment on a copper cathode

    Science.gov (United States)

    Zawisza, Beata; Sitko, Rafał

    2007-10-01

    The electrodepositons of Te, Bi, Ni, Sb and Au from aqueous solution of pH = 1 on the cathode surface have been studied for X-ray fluorescence analysis (XRF). A special holder for a copper electrode has been constructed to perform the electrodeposition process on only one side of the electrode. After electrolysis, the copper electrode can be easily removed from the holder; after rinsing it with water and drying it can be analyzed by XRF. The proposed method of sample preparation and preconcentration of Te, Bi, Ni, Sb, Au provides suitable samples which are devoid of the negative and undesirable effects of XRF analysis, such as particle size and matrix effects. The influence of time on the deposition yield has been examined. The method of preconcentration is efficient. The inhomogeneity of the prepared specimens has been studied using internal standard method. The calibration is based on using synthetic standards, certified reference materials and standard addition method. The best results are achieved by the standard addition method. The agreement between results obtained with XRF analysis and certified values is satisfactory and indicates the usefulness of the proposed method for determination of Te, Bi, Ni, Sb and Au in anode slime.

  7. Interaction of Au, Ag, and Bi ions with Ba2YCu3O(7-y) - Implications for superconductor applications

    Science.gov (United States)

    Hepp, A. F.; Gaier, J. R.; Pouch, J. J.; Hambourger, P. D.

    1988-01-01

    Results are presented on the reactions of Au, Ag, and Bi ions with Ba2YCu3O(7-y) oxides and on the properties of the resultant materials. The results indicate that Au(3+) structural chemistry makes gold an excellent candidate for multiphase structures of the Ba2Y(Cu/1-x/Au/x/)3O(7-y)-type substituted superconductors. Silver is structurally and chemically compatible with the perovskite structure, but when it forms a second phase, it does so without the destruction of the superconducting phase, making silver a useful metal for metal/ceramic applications. On the other hand, bismuth was shown to degrade Tc phase or to form other phases, indicating that it may not be useful in applications with rare-earth-based superconductors.

  8. Formation of recent Pb-Ag-Au mineralization by potential sub-surface microbial activity.

    Science.gov (United States)

    Tornos, Fernando; Velasco, Francisco; Menor-Salván, César; Delgado, Antonio; Slack, John F; Escobar, Juan Manuel

    2014-08-06

    Las Cruces is a base-metal deposit in the Iberian Pyrite Belt, one of the world's best-known ore provinces. Here we report the occurrence of major Pb-Ag-Au mineralization resulting from recent sub-surface replacement of supergene oxyhydroxides by carbonate and sulphide minerals. This is probably the largest documented occurrence of recent microbial activity producing an ore assemblage previously unknown in supergene mineralizing environments. The presence of microbial features in the sulphides suggests that these may be the first-described natural bacteriomorphs of galena. The low δ(13)C values of the carbonate minerals indicate formation by deep anaerobic microbial processes. Sulphur isotope values of sulphides are interpreted here as reflecting microbial reduction in a system impoverished in sulphate. We suggest that biogenic activity has produced around 3.1 × 10(9) moles of reduced sulphur and 10(10) moles of CO2, promoting the formation of ca. 1.19 Mt of carbonates, 114,000 t of galena, 638 t of silver sulphides and 6.5 t of gold.

  9. Heavy-flavour production in high-energy d-Au and p-Pb collisions

    CERN Document Server

    Beraudo, Andrea; Monteno, Marco; Nardi, Marzia; Prino, Francesco

    2015-01-01

    Soft-hadron measurements in high-energy collisions of small systems like p-Pb and d-Au show peculiar qualitative features (long-range rapidity correlations, flattening of the $p_T$-spectra with increasing hadron mass and centrality, non-vanishing Fourier harmonics in the azimuthal particle distributions) suggestive of the formation of a strongly-interacting medium displaying a collective behaviour, with a hydrodynamic flow as a response to the pressure gradients in the initial conditions. Hard observables (high-$p_T$ jet and hadron spectra) on the other hand, within the current large systematic uncertainties, appear only midly modified with the respect to the benchmark case of minimum-bias p-p collisions. What should one expect for heavy-flavour particles, initially produced in hard processes but tending, in the nucleus-nucleus case, to approach kinetic equilibrium with the rest of the medium? This is the issue we address in the present study, showing how the current experimental findings are compatible with ...

  10. Electron-Pair Production in 158 AGeV/c Pb-Au Collisions from CERES

    CERN Document Server

    Yurevich, Sergey

    2006-01-01

    The CERES experiment is devoted to the measurement of low-mass electron pairs in proton and ion-induced collisions at the Super Proton Synchrotron accelerator. The main goal of the CERES experiment is to investigate modifications of hadron properties in hot and dense nuclear matter. A significant enhancement of dilepton pair yield with respect to expectations based on hadron decays was observed in the mass range 0.25 m 0.7 GeV/c. This fascinating result can only be described by models invoking in-medium modifications of the meson. To distinguish between different theoretical explanations of the enhancement the experiment was upgraded in 1998 by the addition of a radial TPC to improve the mass resolution in the vector meson region. In this thesis, the analysis of the data sample taken in 2000 in 158 A GeV/c Pb-Au collisions with the upgraded experimental setup is presented. The observed enhancement of the pairs confirms previous results of CERES. The data, compared to the theoretical calculations based on drop...

  11. Lambda Produktion in Pb-Au Kollisionen bei 40-A-GeV

    CERN Document Server

    Schmitz, Wolfgang

    2001-01-01

    The CERES-experiment at the CERN-SPS investigates the production of electron-positron pairs in ultrarelativistic nuclear collisions. The CERES spectrometer was upgraded during 1998 by the addition of a Time Projection Chamber (TPC) with a radial electric drift field and two coils of a warm magnet to provide a momentum analysis. This thesis deals with the design and construction of the CERES TPC and a first $Lambda$-analysis in 40 A,GeV Pb+Au collisions. The relative momentum resolution $sigma (dp/p)^2$ = $0.027^2+(0.024 ~ p)^2$ (in GeV/c) was determined using the measured width of the $Lambda$ invariant mass spectrum ($sigma$ = 12 MeV/c$^2$) and comparing it to a TPC simulation containing all measured distortions of a trajectory. The resolution is about a factor of 2.5 worse compared to its design value due to the still incomplete calibration. Analysing the fully corrected $Lambda$ transverse momentum spectra in a rapidity interval 2.0 $<$ $y_{m {Lambda}}$ $<$ 2.4 close to midrapidity for centralities $...

  12. Measurement of open charm in 158-AGeV/c Pb - Au collisions

    CERN Document Server

    Ludolphs, Wilrid

    This thesis presents a measurement of an upper limit for the open charm yield in 158 AGeV/c Pb-Au collisions with the CERES spectrometer at 7% centrality. A secondary particle reconstruction scheme, based on the reconstruction of the decay vertex, is developed and tested using the decay K0short -> Pi+ Pi- as a reference measurement. An integrated K0short rapidity density of dN/dy = 19.75 +- 0.23(stat) +- 1.70(syst) is measured in the rapidity region 2.0 K+ Pi- requires careful study of the combinatorial background and resonances contributing to the invariant mass spectrum. An open charm enhancement of more than a factor 22 can be excluded at 98% confidence level. The enhancement is calculated with respect to the expected open charm yield in nucleus-nucleus collisions of = 0.21 per event, obtained by scaling the charm cross-section in proton-proton collisions with the number of binary collisions. The first part of this thesis is devoted to the development of a hit finding algorithm for the CERES TPC. Further...

  13. Au 2PbP 2, Au 2TlP 2, and Au 2HgP 2: Ternary Gold Polyphosphides with Lead, Thallium, and Mercury in the Oxidation State Zero

    Science.gov (United States)

    Eschen, Marcus; Jeitschko, Wolfgang

    2002-05-01

    The polyphosphide Au2PbP2 was prepared by reaction of the elemental components using liquid lead as a reaction medium. Well-developed crystals were obtained after dissolving the matrix in hydrochloric acid. Their crystal structure was determined from four-circle X-ray diffractometer data: Cmcm, a=323.6(1) pm, b=1137.1(2) pm, c=1121.8(1) pm, Z=4, R=0.023 for 478 structure factors and 20 variable parameters. The structure contains zigzag chains of phosphorus atoms with a typical single-bond distance of 219.4(2) pm. The two different kinds of gold atoms are both in linear phosphorus coordination with typical single-bond distances of 232.6(2) and 234.2(2) pm, and the lead atoms have only metal neighbors (7 Au and 2 Pb). Accordingly, chemical bonding of the compound may be expressed by the formula (Au+1)2Pb±0(P-1)2. The corresponding thallium and mercury polyphosphides Au2TlP2 (a=324.1(1) pm, b=1136.1(1) pm, c=1122.1(1) pm) and Au2HgP2 (a=322.1(1) pm, b=1131.4(2) pm, c=1122.6(1) pm) were found to be almost isotypic with Au2PbP2. Their crystal structures were refined from single-crystal X-ray data to R=0.036 (682 F values, 25 variables) and R=0.026 (539 F values, 35 variables), respectively. The structure of these compounds may also be described as consisting of a three-dimensional network of condensed 8- and 10-membered Au2P6 and Au4P6 rings forming parallel channels, which are filled by the lead, thallium, and mercury atoms. The lead atoms are well localized in these channels, while the thallium and even more the mercury atoms occupy additional positions within these channels. Freshly prepared samples of Au2HgP2 show reproducibly slightly different axial ratios and larger cell volumes (ΔV=0.5%) than those after exposure of the samples to air for several days.

  14. Creep Behavior of a Sn-Ag-Bi Pb-Free Solder

    Directory of Open Access Journals (Sweden)

    Alice Kilgo

    2012-11-01

    Full Text Available Compression creep tests were performed on the ternary 91.84Sn-3.33Ag-4.83Bi (wt.%, abbreviated Sn-Ag-Bi Pb-free alloy. The test temperatures were: −25 °C, 25 °C, 75 °C, 125 °C, and 160 °C (± 0.5 °C. Four loads were used at the two lowest temperatures and five at the higher temperatures. The specimens were tested in the as-fabricated condition or after having been subjected to one of two air aging conditions: 24 hours at either 125 °C or 150 °C. The strain-time curves exhibited frequent occurrences of negative creep and small-scale fluctuations, particularly at the slower strain rates, that were indicative of dynamic recrystallization (DRX activity. The source of tertiary creep behavior at faster strain rates was likely to also be DRX rather than a damage accumulation mechanism. Overall, the strain-time curves did not display a consistent trend that could be directly attributed to the aging condition. The sinh law equation satisfactorily represented the minimum strain rate as a function of stress and temperature so as to investigate the deformation rate kinetics: dε/dtmin = Asinhn (ασ exp (−ΔH/RT. The values of α, n, and  ΔH were in the following ranges (±95% confidence interval: α, 0.010–0.015 (±0.005 1/MPa; n, 2.2–3.1 (±0.5; and ΔH, 54–66 (±8 kJ/mol. The rate kinetics analysis indicated that short-circuit diffusion was a contributing mechanism to dislocation motion during creep. The rate kinetics analysis also determined that a minimum creep rate trend could not be developed between the as-fabricated versus aged conditions. This study showed that the elevated temperature aging treatments introduced multiple changes to the Sn-Ag-Bi microstructure that did not result in a simple loss (“softening” of its mechanical strength.

  15. Analysis of shower particle pseudorapidity spectra in interactions of relativistic Au and Pb ions with emulsion nuclei

    Institute of Scientific and Technical Information of China (English)

    B. Z. Belashev; M. K. Suleymanov; S. Vokál; J. Vrláková; M. Ajaz; Ali Zaman; K. H. Khan; Z. Wazir

    2011-01-01

    The pseudorapidity spectra of fast particles (with β > 0.7) produced in Au (at 11.6 A GeV) and Pb (at 158 A GeV) induced collisions with emulsion (Em) nuclei contain some visual plateaus and shoulders.The plateau is wider for Pb+Em reactions compared with the Au+Em ones.The existence of a plateau is expected for parton models.The Fourier transformation and maximum entropy methods were used to get additional information about the plateaus.The dependence of the plateaus on the centrality of the collisions was also studied using the number of g-particles to fix centrality.It shows that the maximum entropy method could confirm the existence of the plateau and the shoulder on distributions.

  16. Oxidation mechanism of a Fe-9Cr-1Mo steel by liquid Pb-Bi eutectic alloy (Part I)

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, L. [CEA, DEN, Service de la Corrosion et du Comportement des Materiaux dans leur Environnement, F-91191 Gif sur Yvette (France)], E-mail: laure.martinelli@cea.fr; Balbaud-Celerier, F.; Terlain, A. [CEA, DEN, Service de la Corrosion et du Comportement des Materiaux dans leur Environnement, F-91191 Gif sur Yvette (France); Delpech, S. [CNRS, UMR 7575 Ecole Nationale superieure de Chimie de Paris, Laboratoire d' Electrochimie et de Chimie Analytique, 11 rue Pierre et Marie Curie 75231 Paris (France); Santarini, G. [CEA, Cabinet du Haut-Commisaire, F-91191 Gif sur Yvette (France); Favergeon, J.; Moulin, G. [CNRS, centre de recherche de Royallieu FRE CNRS 2833, Laboratoire Roberval, 20529-60205 Compiegne (France); Tabarant, M. [CEA, DEN, Service de Chimie Physique, F- 91191 Gif sur Yvette (France); Picard, G. [CNRS, UMR 7575 Ecole Nationale superieure de Chimie de Paris, Laboratoire d' Electrochimie et de Chimie Analytique, 11 rue Pierre et Marie Curie 75231 Paris (France)

    2008-09-15

    This paper is the first part of a global study on the oxidation process of a Fe-9Cr-1Mo martensitic steel (T91) in static liquid Pb-Bi. It focuses on the oxygen transport mode across the oxide scale. The oxide layer has a duplex structure composed of an internal Fe-Cr spinel layer and an external magnetite layer. Oxygen 18 tracer experiments are performed: they show that the magnetite layer grows at the Pb-Bi/ oxide interface whereas the Fe-Cr spinel layer grows at the metal/oxide interface. Oxygen seems to diffuse across the oxide scale dissolved inside nanometric lead penetrations called nano-channels. Specific experiments are performed to characterize the nano-channels.

  17. Results of steel corrosion tests in flowing liquid Pb/Bi at 420-600 deg. C after 2000 h

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, G. E-mail: georg.mueller@ihm.fzk.de; Heinzel, A.; Konys, J.; Schumacher, G.; Weisenburger, A.; Zimmermann, F.; Engelko, V.; Rusanov, A.; Markov, V

    2002-02-01

    Corrosion tests were carried out on austenitic AISI 316L and 1.4970 steels and on MANET steel up to 2000 h of exposure to flowing (up to 2 m/s) Pb/Bi. The concentration of oxygen in the liquid alloy was controlled at 10{sup -6} wt%. Specimens consisted of tube and rod sections in original state and after alloying of Al into the surface. After 2000 h of exposure at 420 and 550 deg. C the specimen surfaces were covered with an intact oxide layer which provided a good protection against corrosion attack of the liquid Pb/Bi alloy. After the same time corrosion attack at 600 deg. C was severe at the original AISI 316L steel specimens. The alloyed specimens containing FeAl on the surface of the alloyed layer still maintained an intact oxide layer with good corrosion protection up to 600 deg. C.

  18. Formation of the 110-K superconducting phase in Pb-doped Bi-Sr-Ca-Cu-O thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kula, W.; Sobolewski, R.; Gorecka, J.; Lewandowski, S.J. (Instytut Fizyki, Polska Akademia Nauk, Al. Lotnikow 32/46, PL-02668 Warszawa (Poland))

    1991-09-15

    Investigation of the 110-K Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub {ital x}} phase formation in superconducting thin films of Bi-based cuprates is reported. The films were dc magnetron sputtered from single Bi(Pb)-Sr-Ca-Cu-O targets of various stoichiometries, and subsequently annealed in air at high temperatures. The influence of the initial Pb content, annealing conditions, as well as the substrate material on the growth of the 110-K phase was investigated. We found that the films, fully superconducting above 100 K could be reproducibly fabricated on various dielectric substrates from Pb-rich targets by optimizing annealing conditions for each initial Pb/Bi ratio. Heavy Pb doping considerably accelerated formation of the 110-K phase, reducing the film annealing time to less than 1 h. Films containing, according to the x-ray measurement, more than 90% of the 110-K phase were obtained on MgO substrates, after sputtering from the Bi{sub 2}Pb{sub 2.5}Sr{sub 2}Ca{sub 2.15}Cu{sub 3.3}O{sub {ital x}} target and annealing in air for 1 h at 870 {degree}C. The films were {ital c}-axis oriented, with 4.5-K-wide superconducting transition, and zero resistivity at 106 K. Their critical current density was 2 {times} 10{sup 2} A/cm{sup 2} at 90 K, and above 10{sup 4} A/cm{sup 2} below 60 K. The growth of the 110-K phase on epitaxial substrates, such as CaNdAlO{sub 4} and SrTiO{sub 3}, was considerably deteriorated, and the presence of the 80- and 10-K phases was detected. Nevertheless, the best films deposited on these substrates were fully superconducting at 104 K and exhibited critical current densities above 2 {times} 10{sup 5} A/cm{sup 2} below 60 K{minus}one order of magnitude greater than the films deposited on MgO.

  19. sup 119 Sn-Moessbauer spectroscopic study of the single phase of Bi(Pb)-Sr-Ca-Cu(Sn)-O

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Y. (Dept. of Electrical Engineering, Fukuoka Univ. (Japan)); Nishida, T. (Dept. of Chemistry, Kyushu Univ., Fukuoka (Japan)); Katada, M. (Dept. of Chemistry, Tokyo Metropolitan Univ. (Japan)); Deshimaru, Y.; Miura, N.; Yamazoe, N. (Dept. of Materials Science and Tech., Graduate School of Engineering Sciences, Kyushu Univ., Fukuoka (Japan))

    1991-12-01

    Tin-doped samples of the high-Tc (2223) phase of Bi-Pb-Sr-Ca-Cu-O superconductor have been prepared by a conventional sintering method. Sintering conditions were carefully selected to obtain the single high-Tc phase. {sup 119}Sn-Moessbauer spectra have been measured in the temperature range from 4.2 to 300 K. The temperature dependence of the recoilless fraction (f) is well understood by the temperature dependence of the normal phonon. (orig.).

  20. Power generation by the transverse Seebeck effect in Pb-Bi{sub 2}Te{sub 3} multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Reitmaier, C.; Walther, F.; Lengfellner, H. [Universitaet Regensburg, Institut fuer Experimentelle und Angewandte Physik, Regensburg (Germany)

    2011-11-15

    The transverse Seebeck effect in tilted metal-semiconductor multilayer structures has been exploited for electric power generation. In tilted Pb-Bi{sub 2}Te{sub 3} multilayer samples, coefficients of performance for transverse thermoelectric power generation have been determined, in dependence of temperature difference between hot and cold sample surfaces. The results can be described well by modeling calculations of transverse thermoelectric power generation. (orig.)

  1. A Study on the Effect of Ni Dopping on Bi-Pb-Sr-Ca-Cu-O System

    OpenAIRE

    ABUKAY, Mustafa TEPE and Doğan

    1998-01-01

    The effect of Ni doping on superconductivity properties of the Bi1.7Pb0.3Sr2Ca2(Cu1-xNix)3Oy system has been investigated by means of x-ray diffraction, ac electrical resistance, ac magnetic susceptibility and critical current measurements. The volume fraction of the 2223 phase decreases with increasing Ni concentration. The zero-resistance temperature and the critical current density are suppressed with Ni substitution.

  2. A Study on the Effect of Ni Dopping on Bi-Pb-Sr-Ca-Cu-O System

    OpenAIRE

    ABUKAY, Mustafa TEPE and Doğan

    2014-01-01

    The effect of Ni doping on superconductivity properties of the Bi1.7Pb0.3Sr2Ca2(Cu1-xNix)3Oy system has been investigated by means of x-ray diffraction, ac electrical resistance, ac magnetic susceptibility and critical current measurements. The volume fraction of the 2223 phase decreases with increasing Ni concentration. The zero-resistance temperature and the critical current density are suppressed with Ni substitution.

  3. Doping of BiScO3-PbTiO3 Ceramics for Enhanced Properties

    Science.gov (United States)

    Sehirlioglu, Alp; Sayir, Ali; Dynys, Fred

    2008-01-01

    High-temperature piezoelectrics are a key technology for aeronautics and aerospace applications such as fuel modulation to increase the engine efficiency and decrease emissions. The principal challenge for the insertion of piezoelectric materials is the limitation on upper use temperature which is due to low Curie-Temperature (T(sub c) and increasing electrical conductivity. BiScO3 -PbTiO3 (BS-PT) system is a promising candidate for improving the operating temperature for piezoelectric actuators due to its high TC (>400 C). Effects of Zr and Mn doping of the BS-PT ceramics have been studied and all electrical and electromechanical properties for Sc-deficient and Ti-deficient BS- PT ceramics are reported as a function of electrical field and temperature. Donor doping with Zr and Mn (in Sc deficient compositions) increased the DC-resistivity and decreased tan at all temperatures. Resulting ceramics exhibited saturated hysteresis loops with low losses and showed no dependence on the applied field (above twice the coercive field) and measurement frequency.

  4. Design Study of Small Pb-Bi Cooled Modified Candle Reactors

    Science.gov (United States)

    Su'ud, Zaki; Sekimoto, H.

    2010-06-01

    In this study application of modified CANDLE burnup scheme based long life Pb-Bi Cooled Fast Reactors for small long life reactors with natural Uranium as Fuel Cycle Input has been performed. The reactor cores are subdivided into several parts with the same volume in the axial directions. The natural uranium is initially put in region 1, after one cycle of 10 years of burn-up it is shifted to region 2, and 10 years after that it is shifted to region 3. This concept is applied to all regions, i.e. shifted the core of I'th region into I+1 region after the end of 10 years burn-up cycle. The first region 1 is filled by fresh natural uranium fuel. Compared to the previous works, in a smaller reactor core the criticality need to be considered more carefully especially at the beginning of life. As an optimized design, a core of 85 cm radius and 150 cm height with 300 MWt power are selected. This core can be operated 10 years without refueling or fuel shuffling. The average discharge burn-up is 350 GWd/ton HM.

  5. Synthesis and evaluation of tetraphosphonates labelled with {sup 212}Bi, {sup 212}Pb and {sup 165}Er

    Energy Technology Data Exchange (ETDEWEB)

    Hassfjell, S.P

    1997-08-01

    The main goal of this work has been to achieve a synthesis of radiolabelled phosphonates for the improvement of diagnostic and therapy of osteoblastic osteosarcoma and sclerotic bone metastases. {sup 212}Bi-DOTMP is shown to be an in vivo stable bone seeking radiopharmaceutical with a potential for a {alpha}-particle therapy of the above mentioned diseases. It has biodistribution characteristics similar to {sup 153}Sm-EDTMP, which is now formally approved in several countries, most recently in the US. {sup 212}Pb-DOTMP is also a promising candidate having the advantage of increasing the effective half life of the {alpha}-emitter, although loss of some of the in vivo generated {sup 212}Bi may be a problem. A generator has been developed for the production of the {alpha}-emitting radionuclide {sup 212}Bi and its parent nuclide {sup 212}Pb. The generator is based on the emanation of {sup 220}Rn from ({sup 228}Th)barium stearate. The decay product of {sup 220}Rn, {sup 212}Pb deposits on the walls of a polyethylene bottle, and can be wasted off with distilled water. The generator shows no leakage of any long-lived parent nuclides, is easy to operate and has a high degree of radiation safety.

  6. Hydrothermal Synthesis Au-Bi2Te3 Nanocomposite Thermoelectric Film with a Hierarchical Sub-Micron Antireflection Quasi-Periodic Structure

    Directory of Open Access Journals (Sweden)

    Junlong Tian

    2015-06-01

    Full Text Available In this work, Au-Bi2Te3 nanocomposite thermoelectric film with a hierarchical sub-micron antireflection quasi-periodic structure was synthesized via a low-temperature chemical route using Troides helena (Linnaeus forewing (T_FW as the biomimetic template. This method combines chemosynthesis with biomimetic techniques, without the requirement of expensive equipment and energy intensive processes. The microstructure and the morphology of the Au-Bi2Te3 nanocomposite thermoelectric film was analyzed by X-ray diffraction (XRD, field-emission scanning-electron microscopy (FESEM, and transmission electron microscopy (TEM. Coupled the plasmon resonances of the Au nanoparticles with the hierarchical sub-micron antireflection quasi-periodic structure, the Au-Bi2Te3 nanocomposite thermoelectric film possesses an effective infrared absorption and infrared photothermal conversion performance. Based on the finite difference time domain method and the Joule effect, the heat generation and the heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film were studied. The heterogeneity of heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film opens up a novel promising technique for generating thermoelectric power under illumination.

  7. Sr-Nd-Pb-Hf isotope systematics of the Hugo Dummett Cu-Au porphyry deposit (Oyu Tolgoi, Mongolia)

    Science.gov (United States)

    Dolgopolova, A.; Seltmann, R.; Armstrong, R.; Belousova, E.; Pankhurst, R. J.; Kavalieris, I.

    2013-04-01

    Major and trace element geochemistry including Sr-Nd-Pb-Hf isotopic data are presented for a representative sample suite of Late Devonian to Early Carboniferous plutonic and volcanic rocks from the Hugo Dummett deposit of the giant Oyu Tolgoi porphyry Cu-Au district in South Gobi, Mongolia. Sr and Nd isotopes (whole-rock) show restricted ranges of initial compositions, with positive ɛNdt mainly between + 3.4 and + 7.4 and (87Sr/86Sr)t predominantly between 0.7037 and 0.7045 reflecting magma generation from a relatively uniform juvenile lithophile-element depleted source. Previously dated zircons from the plutonic rocks exhibit a sample-averaged range of ɛHft values of + 11.6 to + 14.5. Depleted-mantle model ages of 420-830 (Nd) and 320-730 Ma (zircon Hf) limit the involvement of pre-Neoproterozoic crust in the petrogenesis of the intermediate to felsic calc-alkaline magmas to, at most, a minor role. Pb isotopes (whole-rock) show a narrow range of unradiogenic initial compositions: 206Pb/204Pb 17.40-17.94, 207Pb/204Pb 15.43-15.49 and 208Pb/204Pb 37.25-37.64, in agreement with Sr-Nd-Hf isotopes indicating the dominance of a mantle component. All four isotopic systems suggest that the magmas from which the large Oyu Tolgoi porphyry system was generated originated predominantly from juvenile material within the subduction-related setting of the Gurvansayhan terrane.

  8. Production of neutral pions Pb+Au collisions at 158 AGeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Soualah, Rachik

    2009-06-24

    The direct photons are a particularly useful probe to search for an evidence of the Quark-Gluon Plasma formation in ultra-relativistic heavy-ion collisions. Direct photons can be extracted experimentally by measuring the large background from {pi}{sup 0} and {eta} meson decays. This thesis work represents the production of the neutral pion mesons measured with the CERES/NA45 experiment at the top SPS energy in 158 AGeV/c Pb-Au collisions. The {pi}{sup 0} {yields} {gamma}{gamma} (98.8%) is the decay channel used in the reconstruction scheme. The {pi}{sup 0} measurement is based on the data taken in the year 2000. The CERES experiment can measure the photons that convert shortly before the TPC by measuring the e{sup +}e{sup -} pairs in the TPC. The RICH2 mirror is the main converter used for this analysis. The presented analysis method describes in more details the selection of the e{sup +} and e{sup -} tracks using only the TPC information to reconstruct the converted photon. A Secondary vertex technique was developed and used to select the photons converted in the RICH2 mirror area. The extraction of the {pi}{sup 0} needs a careful study of the combinatorial background determined using the mixed event technique. The obtained invariant mass distribution of the two photons defined well the {pi}{sup 0} peak. The neutral pion transverse spectra compared to phenomenological models and other experiments validate our analysis method. (orig.)

  9. Distribution of electron density in BaPb{sub 1-x}Bi{sub x}O{sub 3} evidenced by {sup 207}Pb and {sup 17}O NMR

    Energy Technology Data Exchange (ETDEWEB)

    Trokiner, Arlette; Piskunov, Yuri; Gerashenko, Alexander; Pogudin, Anton; Mikhalev, Konstantin; Yakubovsky, Andrey; Verkhovskii, Stanislav

    2004-08-01

    The inhomogeneous magnetic broadening of the {sup 17}O and {sup 207}Pb NMR spectra resulting from a distribution of the Knight shifts was studied in the metallic phase of BaPb{sub 1-x}Bi{sub x}O{sub 3} oxides (0{<=}x{<=}0.33). It was shown that Bi atoms, which are randomly incorporated in the parent BaPbO{sub 3}, give rise to an increased spin density of carriers within the two first cation shells. The percolative overlap of these areas is expected for superconducting compositions (x>0.1)

  10. Colorimetric Detection of Pb2+ Using Au Nanoparticles Cofunctionalized with L-cystine and Diethylphosphatoethyltriethoxysilane%L-胱氨酸功能化的Au@SiO2-DPTS比色检测Pb2+

    Institute of Scientific and Technical Information of China (English)

    杨倩; 曹小红; 张志宾; 刘云海

    2015-01-01

    以具有核-壳结构的Au@SiO2纳米颗粒为基底,用二乙基磷酰乙基三乙氧基硅烷(DPTS)和L-胱氨酸(L-Cystine)对其进行功能化修饰制备得二乙基磷酰乙基三乙氧基硅烷和L-胱氨酸功能化纳米金粒子(L-Cys-Au@SiO2-DPTS),利用羧酸根及磷酸根与铅离子形成金属螯合物后,引起纳米粒子的聚集,导致溶液由酒红色变为蓝色,这种颜色的转变可通过肉眼直接识别,从而建立起一种简单,快速且的可用于现场实时检测pb2+的可视化比色检测的方法.通过优化pH、底物浓度和反应时间等条件后,相较于Ni2+,Co2,Mn2+等9种金属离子,L-Cys-Au@SiO2-DPTS对pb2+显示出了极高的选择性.在最优实验条件下,检测pb2+时,浓度在10-5~10-4 mol/L范围内呈现出良好的线性关系(R2=0.9983),最低检测限为3.43×10-8 mol/L.

  11. Effects of Dopant on Depoling Temperature in Modified BiScO3 - PbTiO3

    Science.gov (United States)

    Kowalski, Benjamin; Sehirlioglu, Alp

    2014-01-01

    In recent years there has been a renewed interest for high temperature piezoelectrics for both terrestrial and aerospace applications. These applications are limited in part by the operating temperature, which is usually taken as one half of the Curie temperature (Tc), and is 200C for one of the most widely used commercial piezoelectrics, Pb(Zr,Ti)O3 (PZT). In an effort to increase Tc, subsequent research into high temperature Bi(BB)O3 PbTiO3 piezoelectrics led to the discovery of the morphotropic phase boundary (MPB) in the high-Tc BiScO3 PbTiO3 (BS-PT) system with a Tc of 460C and a d33 of 460 pmV. The Tc marks the ferroelectric to paraelectric phase transformation and while, in general, a phase transformation leads to thermal depoling in piezoelectrics with low or moderate Tcs, for high Tc piezoelectrics thermally assisted dipole rotation can lead to randomization of domains at temperatures below Tc. It becomes necessary to determine the depoling temperature (Td) which dictates the actual working temperature range. By doping for Sc and Ti the Td can be shifted while maintaining similar electromechanical properties as a function of temperature. The effect of this B-site doping on depoling temperature has been explored through the characterization of microstructure and weakhigh field measurements.

  12. Separation of 210Pb, 210Bi and 210Po by ion exchange and their Iiquid scintillation standardization; Separacion del 210Pb, 210Bi y 2I0Po mediante columna de cambio ionico y su calibracion por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.; Jimenez, A.; Grau, A.

    1996-07-01

    We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''TM II, HiSafe''TM III, Ultima-Gold''TM, Ultima-Gold''TM XR, Ultima-Gold''TM AB, Insta-Gel''R and e Insta-Gel''R lI. Also we analyzed the disequilibrium of the radioactive chain 210Pb+210Bi+210Po, achieving an excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs.

  13. Energy release, beam attenuation radiation damage, gas production and accumulation of long-lived activity in Pb, Pb-Bi and Hg targets

    Energy Technology Data Exchange (ETDEWEB)

    Shubin, Yu.N. [IPPE, Obninsk (Russian Federation)

    1996-06-01

    The calculation and analysis of the nuclei concentrations and long-lived residual radioactivity accumulated in Pb, Pb-Bi and Hg targets irradiated by 800 MeV, 30 mA proton beam have been performed. The dominating components to the total radioactivity of radionuclides resulting from fission and spallation reactions and radiative capture by both target nuclei and accumulated radioactive nuclei for various irradiation and cooling times were analyzed. The estimations of spectral component contributions of neutron and proton fluxes to the accumulated activity were carried out. The contributions of fission products to the targets activity and partial activities of main long-lived fission products to the targets activity and partial activities of main long-lived fission products were evaluated. The accumulation of Po isotopes due to reactions induced by secondary alpha-particles were found to be important for the Pb target as compared with two-step radiative capture. The production of Tritium in the targets and its contribution to the total targets activity was considered in detail. It is found that total activities of both targets are close to one another.

  14. Residue excitation functions from complete fusion of [sup 16]O with [sup 197]Au and [sup 208]Pb

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, K.; Caraley, A.L.; Fineman, B.J.; Gan, N.; Velkovska, J.; McGrath, R.L. (Physics Department, State University of New York at Stony Brook, Stony Brook, New York 11794 (United States))

    1994-07-01

    Evaporation residue excitation functions and [alpha]-multiplicities from complete fusion of [sup 16]O with [sup 197]Au and [sup 208]Pb have been measured from the fusion threshold up to 140 MeV incident energy. The data allow the conclusion that strongly overdamped motion cannot be dominant at energies in the vicinity of the fusion barrier below [ital E][sup *][approx]50 MeV. At excitation energies above 50 MeV the residue cross section for [sup 16]O+[sup 208]Pb is much greater than predicted from the statistical model with conventional parametrizations. The enhancement is not explained by incorporating dynamical effects into the analysis. An alternative suggestion based on deexcitation-chain dependent fission barriers is discussed.

  15. Long range absorption in the scattering of He-6 on Pb-208 and Au-197 at 27-MeV

    OpenAIRE

    Kakuee, O. R.; Alvarez, M. A. G.; Andres, M. V.; Cherubini, S.; Davinson, T.; Di Pietro, A.; Galster, W.; Gomez-Camacho, J.; Laird, A M; Lamehi-Rachti, M.; Martel, I.; Moro, A. M.; Rahighi, J.; Sanchez-Benitez, A M; Shotter, A.C.

    2005-01-01

    Quasi-elastic scattering of 6He at E_lab=27 MeV from 197Au has been measured in the angular range of 6-72 degrees in the laboratory system employing LEDA and LAMP detection systems. These data, along with previously analysed data of 6He + 208Pb at the same energy, are analyzed using Optical Model calculations. The role of Coulomb dipole polarizability has been investigated. Large imaginary diffuseness parameters are required to fit the data. This result is an evidence for lo...

  16. Long range absorption in the scattering of 6He on 208Pb and 197Au at 27 MeV

    CERN Document Server

    Kakuee, O R; Andrés, M V; Cherubini, S; Davinson, T; Pietro, A D; Galster, W; Gómez-Camacho, J; Laird, A M; Lamehi-Rachti, M; Martel, I; Moro, A M; Rahighi, J; Sanchez-Benitez, A M; Shotter, A C; Smith, W B; Vervier, J; Woods, P J

    2006-01-01

    Quasi-elastic scattering of 6He at E_lab=27 MeV from 197Au has been measured in the angular range of 6-72 degrees in the laboratory system employing LEDA and LAMP detection systems. These data, along with previously analysed data of 6He + 208Pb at the same energy, are analyzed using Optical Model calculations. The role of Coulomb dipole polarizability has been investigated. Large imaginary diffuseness parameters are required to fit the data. This result is an evidence for long range absorption mechanisms in 6He induced reactions.

  17. Spectroscopic properties of B2O3-PbO-Bi2O3-GeO2 glass doped with Sm3+ and gold nanoparticles

    Science.gov (United States)

    Herrera, A.; Buchner, S.; Camerini, R. V.; Jacinto, C.; Balzaretti, N. M.

    2016-02-01

    Heavy metal oxide B2O3-PbO-Bi2O3-GeO2 transparent glass doped with Sm3+ was synthesized and implanted with Au+ using energy of 300 keV and fluence of 1 × 1016 cm-2. The annealing of the implanted glass at moderate temperature below the glass transition temperature induced the nucleation of gold nanoparticles, confirmed by the characteristic absorption band in the visible range and by transmission electron microscopy. Using Miés and Doylés theories for the surface plasmon resonance, the average size of the gold nanoparticles was about 4.6 nm, similar to the values observed by transmission electron microscopy. It was also observed the crystallization of a thin layer of the glass at the implanted surface after annealing, detected by X-ray diffraction and scanning electron microscope. Visible and near-infrared emission of Sm3+ was enhanced after annealing of the glass implanted with gold. Judd-Ofelt parameters and radiative parameters were calculated for the glass doped with Sm3+ with and without gold nanoparticles.

  18. Coordination chemistry of the {sup 212}Pb/{sup 212}Bi nuclear transformation: Alpha-emitting radiopharmaceuticals. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Parks, N.J.; Harris, W.R.; Keen, C.L.; Cooper, S.R.

    1992-07-01

    Subdivisions of this project are: (a) the synthesis of prototypical thiolate and dithiocarbamate based hexacoordinate complexes, (b) radiochemical engineering for generation of no-carrier-added lead and bismuth radioelements, (c) the first isolation of bismuth-binding proteins from in vivo studies with cyclotron produced {sup 205/206}Bi tracer, and (d) initial development of transport mechanisms for the intracellular radiobiological study of alpha emitting bismuth, and (e) the initiation of chemical equilibrium studies and biochemical pathways with cyclotron-produced, no-carrier-added, {sup 203}Pb (T{sub 1/2} = 51 hr).

  19. Seebeck effect in superconducting BaPb sub(1-x)Bi sub(x) O/sub 3/ system

    Energy Technology Data Exchange (ETDEWEB)

    Tani, T.; Itoh, T.; Tanaka, S. (Tokyo Univ. (Japan). Faculty of Engineering)

    1980-01-01

    Seebeck effect was observed on superconducting BaPb sub(1-x)Bi sub(x)O/sub 3/ system in x = 0 -- 0.4 from 4.2K or T sub(c) to 300K. Seebeck coefficient seems to consist of two contributions; one from the dominant metallic electrons and the other from additional unidentified carriers with fairly low mobility. The calculated epsilon sub(F), N(epsilon sub(F)) and m* from the metallic contribution tend to increase with x to maxima around x = 0.2, where T sub(c) also becomes maximum.

  20. x-T phase diagram of La-substituted BiFeO3-PbTiO3

    Directory of Open Access Journals (Sweden)

    K. K. Mishra

    2011-09-01

    Full Text Available Single-phase polycrystalline powders of 0.5(Bi1-xLaxFeO3-0.5PbTiO3 solid-solution were synthesized for x ≤ 0.3 using solid-state reaction method. The mixed crystals exhibit a tetragonal structure at ambient and the c/a ratio decreases with x. In-situ X-ray diffraction measurements at elevated temperatures show a structural transition to a cubic phase. The transition temperatures have been obtained for different x and a x-T phase diagram has been proposed.

  1. Analysis of different modeling approach at determining of backward extrusion force on AlCu5PbBi material

    Directory of Open Access Journals (Sweden)

    B. Barišić

    2008-10-01

    Full Text Available The goal of the paper is to present an outline of different modeling approach at determining of backward extrusion force on AlCu5PbBi material and to compare them with experimental obtained results. Stochastic modeling in the paper is based on the statistic processing of central composite experimental design i.e. in this investigations central composite circumscribed (CCC design. The numerical modeling is based on the finite element method (FEM using ABAQUS 6.4.1. Explicit software.

  2. The age of Au-Cu-Pb-bearing veins in the poly-orogenic Ubendian Belt (Tanzania): U-Th-total Pb dating of hydrothermally altered monazite

    Science.gov (United States)

    Kazimoto, Emmanuel Owden; Schenk, Volker; Appel, Peter

    2015-01-01

    The age of gold-copper-lead mineralization in the Katuma Block of the Ubendian Belt remains controversial because of the lack of radiometric ages that correlate with the age of tectonothermal events of this poly-orogenic belt. Previous studies reported whole rock and mineral Pb-Pb ages ranging between 1,660 and 720 Ma. In this study, we report U-Th-total Pb ages of monazite from hydrothermally altered metapelites that host the Au-Cu-Pb-bearing veins. Three types of chemically and texturally distinct types of monazite grains or zones of grains were identified: monazite cores, which yielded a metamorphic age of 1,938 ± 11 Ma ( n = 40), corresponding to known ages of a regional metamorphic event, deformation and granitic plutonism in the belt; metamorphic overgrowths that date a subsequent metamorphic event at 1,827 ± 10 Ma ( n = 44) that postdates known eclogite metamorphism (at ca. 1,880 Ma) in the belt; hydrothermally altered poikilitic monazite, formed by dissolution-precipitation processes, representing the third type of monazite, constrain the age of a hydrothermal alteration event at 1,171 ± 17 Ma ( n = 19). This Mesoproterozoic age of the hydrothermal alteration coincides with the first amphibolite grade metamorphism of metasediments in the Wakole Block, which adjoins with a tectonic contact the vein-bearing Katuma Block to the southwest. The obtained distinct monazite ages not only constrain the ages of metamorphic events in the Ubendian Belt, but also provide a link between the metamorphism of the Wakole metasediments and the generation of the hydrothermal fluids responsible for the formation of the gold-copper-lead veins in the Katuma Block.

  3. Excitation functions of parameters extracted from three-source (net-)proton rapidity distributions in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Li-Na; Liu, Fu-Hu [Shanxi University, Institute of Theoretical Physics, Taiyuan, Shanxi (China); Sun, Yan; Sun, Zhu [Shanxi Datong University, Department of Physics, Datong, Shanxi (China); Lacey, Roy A. [Stony Brook University, Departments of Chemistry and Physics, Stony Brook, NY (United States)

    2017-03-15

    Experimental results of the rapidity spectra of protons and net-protons (protons minus antiprotons) emitted in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions, measured by a few collaborations at the alternating gradient synchrotron (AGS), super proton synchrotron (SPS), and relativistic heavy ion collider (RHIC), are described by a three-source distribution. The values of the distribution width σ{sub C} and fraction k{sub C} of the central rapidity region, and the distribution width σ{sub F} and rapidity shift Δy of the forward/backward rapidity regions, are then obtained. The excitation function of σ{sub C} increases generally with increase of the center-of-mass energy per nucleon pair √(s{sub NN}). The excitation function of σ{sub F} shows a saturation at √(s{sub NN}) = 8.8 GeV. The excitation function of k{sub C} shows a minimum at √(s{sub NN}) = 8.8 GeV and a saturation at √(s{sub NN}) ∼ 17 GeV. The excitation function of Δy increases linearly with ln(√(s{sub NN})) in the considered energy range. (orig.)

  4. Mechanical Properties of (Bi,Pb)-2223 Multifilament Tapes with Ag-Alloy Sheath

    Institute of Scientific and Technical Information of China (English)

    LIANG Ting; QU Ti-Ming; LI Pei; HAN Zheng-He

    2006-01-01

    @@ Ag-Mg-V alloy is prepared and investigated to develop a new sheath alloy used for BSCCO tapes. Bi-2223 Ag/AgMgV and Bi-2223 AgMgV/AgMgV tapes are studied with the help of stress-strain measurement, optical microstructure and critical current Ic.

  5. Effect of elastic stress on the resistivity and Tc of (Bi,Pb) sub 2 Sr sub 2 Ca sub n-1 Cu sub n O sub x. [BiPbSrCaCuO

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xinfen; Tessema, G.X.; Skove, M.J. (Dept. of Physics and Astronomy, Clemson Univ., SC (United States))

    1991-10-10

    We have measured the effect of elastic uniaxial stress {sigma} in the a direction on the superconducting transition temperature Tc of (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 1}Ca{sub 2}O{sub x} (2212) and (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (2223). We find dT/d{sigma}{sub 11}=-10{+-}2 K/GPa for 2212 and -6{+-}2K/GPa for the 2223 compound. Combining these results with those of others on dTc/dP we find that dTc/d{sigma}{sub 33}=+18K/GPa. An estimate of the elastic constants of these compounds from the work of others together with these results implies that the change in Tc with a fractional change in the c-axis spacing is probably positive, although the uncertainties in the elastic constants make this estimate subject to a large uncertainty. The resistance changes by less than 1 part in 12000 for strains up to 0.5%, implying that dln {rho}/d{sigma}{sub 11}=-76x10{sup -3} GPa{sup -1}. (orig.).

  6. Detailed analysis of two particle correlations in central Pb-Au collisions at 158 GeV per nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Antonczyk, D.

    2006-07-01

    This thesis presents a two-particle correlation analysis of the fully calibrated high statistics CERES Pb+Au collision data at the top SPS energy, with the emphasis on the pion-proton correlations and the event-plane dependence of the correlation radii. CERES is a dilepton spectrometer at CERN SPS. After the upgrade, which improved the momentum resolution and extended the detector capabilities to hadrons, CERES collected 30 million Pb+Au events at 158 AGeV in the year 2000. A previous Hanbury-Brown-Twiss (HBT) analysis of pion pairs in a subset of these data, together with the results obtained at other beam energies, lead to a new freeze-out criterion [AAA+03]. In this work, the detailed transverse momentum and event-plane dependence of the pion correlation radii, as well as the pion-proton correlations, are discussed in the framework of the blast wave model of the expanding fireball. Furthermore, development of an electron drift velocity gas monitor for the ALICE TPC sub-detector is presented. The new method of the gas composition monitoring is based on the simultaneous measurement of the electron drift velocity and the gas gain and is sensitive to even small variations of the gas mixture composition. Several modifications of the apparatus were performed resulting in the final drift velocity resolution of 0.3 permille. (orig.)

  7. Study on borate glass system containing with Bi 2O 3 and BaO for gamma-rays shielding materials: Comparison with PbO

    Science.gov (United States)

    Kaewkhao, J.; Pokaipisit, A.; Limsuwan, P.

    2010-04-01

    In this work, the mass attenuation coefficients and shielding parameters of borate glass matrices containing with Bi 2O 3 and BaO have been investigated at 662 keV, and compare with PbO in same glass structure. The theoretical values were calculated by WinXCom software and compare with experiential data. The results found that the mass attenuation coefficients were increased with increasing of Bi 2O 3, BaO and PbO concentration, due to increase photoelectric absorption of all glass samples. However, Compton scattering gives dominant contribution to the total mass attenuation coefficients for studied glass samples. Moreover the half value layers (HVL) of glass samples were also better than ordinary concretes and commercial window glass. These results reflecting that the Bi-based glass can use replace Pb in radiation shielding glass. In the case of Ba, may be can use at appropriate energy such as X-rays or lower.

  8. Infrared study of Er(3+)/Yb(3+) Co-Doped GeO(2)-PbO-Bi(2)O(3) glass.

    Science.gov (United States)

    Bahari, Hamid-Reza; Sidek, Hj A A; Adikan, Faisal Rafiq M; Yunus, Wan M M; Halimah, Mohamed K

    2012-01-01

    Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE) doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO(2)-PbO-Bi(2)O(3) glass host doped with Er(3+)/Yb(3+) ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR) results showed that PbO and Bi(2)O(3) participate with PbO(4) tetragonal pyramids and strongly distort BiO(6) octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.

  9. The energy spectrum of PbBi4Te7 on evidence derived from light reflection and absorption coefficients

    Directory of Open Access Journals (Sweden)

    Alexander N. Veis

    2015-10-01

    The compound under study was established to exhibit a narrow direct forbidden gap. It was found that its optical band gap Egopt=0.31eV, an energy gap parameter Eg0 between absolute extremums of the valence and conduction bands in the sample with the Hall electron concentration of 5.45 × 1020 cm–3 was equal to 0.08–0.12 eV, and a mdn/mdp ratio (effective masses of electron and hole states densities was equal to about unity. No other subbands located near the absolute extremum of conduction band were revealed in PbBi4Te7. The electron dispersion law was also found to be non-parabolic in this matter. The law involved can be described in the context of Kane non-parabolisity model taking into account an exchange interaction of free electrons. It was shown that the most probable value of the Eg0 parameter fell within the range from 0.16 to 0.24 eV for PbBi4Te7 with nondegenerate free electron gas.

  10. Tl-208, Pb-212, Bi-212, Ra-226 and Ac-228 adsorption onto polyhydroxyethylmethacrylate-bentonite composite

    Energy Technology Data Exchange (ETDEWEB)

    Akkaya, Recep [Cumhuriyet University, Chemistry Department, 58140 Sivas (Turkey); Ulusoy, Ulvi, E-mail: ulusoy@cumhuriyet.edu.tr [Cumhuriyet University, Chemistry Department, 58140 Sivas (Turkey)

    2012-02-01

    The adsorption of naturally occurring radionuclides ({sup 208}Tl{sup +}, {sup 212}Pb{sup 2+}, {sup 226}Ra{sup 2+}, {sup 212}Bi{sup 3+} and {sup 228}Ac{sup 3+}) onto Polyhydroxyethylmethacrylate-bentonite (PHEMA-B) composite was investigated. Experimentally obtained isotherms were evaluated with reference to Langmuir, Freundlich and Dubinin-Radushkevich (DR) models. The adsorption isotherms were L type of Giles classification proving that PHEMA-B had a high affinity adsorbent for the studied radionuclides. The Langmuir adsorption capacities (X{sub L}) were in the order of {sup 226}Ra (2.8 MBq kg{sup -1})>{sup 212}Bi (0.4 MBq kg{sup -1})>{sup 212}Pb (0.3 MBq kg{sup -1})>{sup 228}Ac and {sup 208}Tl (0.2 MBq kg{sup -1}). The adsorption process was physical via complex formation after proton exchanger for which the adsorption energies obtained from DR model was evidence. The enthalpy and entropy changes were positive and the negative free enthalpy change was proof for the spontaneity of adsorption. The reusability tests for PHEMA-B for five uses demonstrated that the adsorbent could be reused after complete recovery of the loaded radionuclide ions by 1 M HCl. The chemical structure of the composite did not change after the reuses and storage foregoing.

  11. Electronic and Optical Properties of Ca3MN (M = Ge, Sn, Pb, P, As, Sb and Bi) Antiperovskite Compounds

    Science.gov (United States)

    Iqbal, Samad; Murtaza, G.; Khenata, R.; Mahmood, Asif; Yar, Abdullah; Muzammil, M.; Khan, Matiullah

    2016-08-01

    The electronic and optical properties of cubic antiperovskites Ca3MN (M = Ge, Sn, Pb, P, As, Sb and Bi) were investigated by applying the full potential linearized augmented plane wave plus local orbitals (FP-LAPW + lo) scheme based on density functional theory. Different exchange correlation potentials were adopted for the calculations. The results of band structure and density of states show that, by changing the central anion of Ca3MN, the nature of the materials change from metallic (Ca3GeN, Ca3SnN, Ca3PbN) to semiconducting with small band gaps (Ca3SbN and Ca3BiN) to insulating (Ca3PN and Ca3AsN). The optical properties such as dielectric function, absorption coefficient, optical conductivity, reflectivity and refractive indices have also been calculated. The results reveal that all the studied compounds are optically active in the visible and ultraviolet energy regions, and therefore can be effectively utilized for optoelectronic devices.

  12. Microstructure and electrical properties of pure 110K phase in the BiPbSrCaCuO system

    Science.gov (United States)

    Holguin, E.; Berger, H.; Lévy, F.; Dwir, B.; Pavuna, D.; Burri, G.

    1991-01-01

    The temperature dependence of the d.c. resistivity and a.c. magnetic susceptibility was investigated in bulk ceramics of the BiPbSrCaCuO system with 2212 - free (2223) phase. The temperature domain needed to synthesize this phase was small and, according to the actual temperature used, the superconducting properties of the samples were strongly modified. The corresponding X-ray diffraction lines of the 110K phase can be indexed in the pseudo-orthorhombic unit cell with parameters 5.40x5.41x37Å 3. SEM microprobe study revealed the presence of several non-superconducting phases and a composition 2.1:0.1:2:2:3 for the cation ratio Bi:Pb:Sr:Ca:Cu of the 110K phase. Electrical measurements (d.c. resistivity and a.c. susceptibility) confirmed the existence of a 2212 - free (2223) phase. A low temperature "tail" in the d.c. electrical resistivity marks the low value of critical current in the samples.

  13. Tl-208, Pb-212, Bi-212, Ra-226 and Ac-228 adsorption onto polyhydroxyethylmethacrylate-bentonite composite

    Science.gov (United States)

    Akkaya, Recep; Ulusoy, Ulvi

    2012-02-01

    The adsorption of naturally occurring radionuclides ( 208Tl +, 212Pb 2+, 226Ra 2+, 212Bi 3+ and 228Ac 3+) onto Polyhydroxyethylmethacrylate-bentonite (PHEMA-B) composite was investigated. Experimentally obtained isotherms were evaluated with reference to Langmuir, Freundlich and Dubinin-Radushkevich (DR) models. The adsorption isotherms were L type of Giles classification proving that PHEMA-B had a high affinity adsorbent for the studied radionuclides. The Langmuir adsorption capacities ( XL) were in the order of 226Ra (2.8 MBq kg -1)> 212Bi (0.4 MBq kg -1)> 212Pb (0.3 MBq kg -1)> 228Ac and 208Tl (0.2 MBq kg -1). The adsorption process was physical via complex formation after proton exchanger for which the adsorption energies obtained from DR model was evidence. The enthalpy and entropy changes were positive and the negative free enthalpy change was proof for the spontaneity of adsorption. The reusability tests for PHEMA-B for five uses demonstrated that the adsorbent could be reused after complete recovery of the loaded radionuclide ions by 1 M HCl. The chemical structure of the composite did not change after the reuses and storage foregoing.

  14. Overpotential deposition of Ag monolayer and bilayer on Au(1 1 1) mediated by Pb adlayer underpotential deposition/stripping cycles

    Science.gov (United States)

    Wang, J. X.; Ocko, B. M.; Adzic, R. R.

    2003-08-01

    Ultra-thin Ag films on the Au(1 1 1) surface were prepared via overpotential deposition (OPD) in the presence of Pb 2+ ions. By carrying out repetitive Pb adlayer underpotential deposition (UPD) and stripping cycles during Ag bulk deposition, the two-dimensional growth of Ag films was significantly enhanced in high OPD. The Ag monolayer sample was made by comparing the voltammetry curves, in which the signatures for Pb adlayer UPD on Au(1 1 1) changed to that on Ag(1 1 1). As demonstrated by the X-ray specular reflectivity measurements, nearly complete monolayer and bilayer films can be made with optimized deposition procedures. On subatomic scale, however, we found that these films have significant higher root-mean-square displacement amplitudes than those underpotentially deposited Ag monolayer and bilayer on either Au(1 1 1) or Pt(1 1 1).

  15. Structures and ionic conductivities in two fluorite type families: Pb{sub 5}Bi{sub 17}X{sub 5}O{sub 43} and Pb{sub 5}Bi{sub 18}X{sub 4}O{sub 42} (X = P, V and As)

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, S.; Obbade, S.; Wignacourt, J.P. [Ecole Nationale Superieure de Chimie de Lille, Lab. de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012, 59 - Villeneuve d' Ascq (France); Giraud, S. [University of Texas, Texas Materials Institute and Dept. of Chemical Engineering, Austin, TX (United States); Suard, E.; Steinfink, H. [Institut Laue-Langevin - ILL, 38 - Grenoble (France)

    2003-02-01

    The phases Pb{sub 5}Bi{sub 17}P{sub 5}O{sub 43} and Pb{sub 5}Bi{sub 18}P{sub 4}O{sub 42} are among many recent new oxy-phosphates discovered in the ternary system PbO-Bi{sub 2}O{sub 3}-P{sub 2}O{sub 5}. The syntheses of the vanadates and arsenates led to isostructural compounds. Both series display a distorted 3 x 3 x 3 superstructure of the tetragonal {delta}-Bi{sub 2}O{sub 3} polymorph. These types of phases display interesting anion conductivities and measurements were performed from 300 deg. C to 800 deg. C on the phosphates, arsenates and vanadates of the two families. The Pb{sub 5}Bi{sub 18}X{sub 4}O{sub 42} phases have higher conductivity values than those of Pb{sub 5}Bi{sub 17}X{sub 5}O{sub 43}. Of the three homologues the vanadates always have the highest conductivities, i.e., at 800 deg. C: 1.6 x 10{sup -2} Siemens.cm{sup -1} for Pb{sub 5}Bi{sub 18}V{sub 4}O{sub 42} and 1.6 x 10{sup -3} Siemens.cm{sup -1} for Pb{sub 5}Bi{sub 17}V{sub 5}O{sub 43}. An increase of the volume of the unit cell due to the increasing radius of the pentavalent cations from P, As to V, 0.34 Angstrom, 0.47 Angstrom, 0.59 Angstrom respectively, helps the anion migration through the structure. (authors)

  16. Trace- and rare-earth element geochemistry and Pb-Pb dating of black shales and intercalated Ni-Mo-PGE-Au sulfide ores in Lower Cambrian strata, Yangtze Platform, South China

    Science.gov (United States)

    Jiang, Shao-Yong; Chen, Yong-Quan; Ling, Hong-Fei; Yang, Jing-Hong; Feng, Hong-Zhen; Ni, Pei

    2006-08-01

    The Lower Cambrian black shale sequence of the Niutitang Formation in the Yangtze Platform, South China, hosts an extreme metal-enriched sulfide ore bed that shows >10,000 times enrichment in Mo, Ni, Se, Re, Os, As, Hg, and Sb and >1,000 times enrichment in Ag, Au, Pt, and Pd, when compared to average upper continental crust. We report in this paper trace- and rare-earth-element concentrations and Pb-Pb isotope dating for the Ni-Mo-PGE-Au sulfide ores and their host black shales. Both the sulfide ores and their host black shales show similar trace-element distribution patterns with pronounced depletion in Th, Nb, Hf, Zr, and Ti, and extreme enrichment in U, Ni, Mo, and V compared to average upper crust. The high-field-strength elements, such as Zr, Hf, Nb, Ta, Sc, Th, rare-earth elements, Rb, and Ga, show significant inter-element correlations and may have been derived mainly from terrigenous sources. The redox sensitive elements, such as V, Ni, Mo, U, and Mn; base metals, such as Cu, Zn, and Pb; and Sr and Ba may have been derived from mixing of seawater and venting hydrothermal sources. The chondrite-normalized REE patterns, positive Eu and Y anomalies, and high Y/Ho ratios for the Ni-Mo-PGE-Au sulfide ores are also suggestive for their submarine hydrothermal-exhalative origin. A stepwise acid-leaching Pb-Pb isotope analytical technique has been employed for the Niutitang black shales and the Ni-Mo-PGE-Au sulfide ores, and two Pb-Pb isochron ages have been obtained for the black shales (531±24 Ma) and for the Ni-Mo-PGE-Au sulfide ores (521±54 Ma), respectively, which are identical and overlap within uncertainty, and are in good agreement with previously obtained ages for presumed age-equivalent strata.

  17. Nuclear level densities in 208Bi and 209Po from the neutron spectra in the ( p, n) reactions on 208Pb and 209Bi nuclei

    Science.gov (United States)

    Zhuravlev, B. V.; Lychagin, A. A.; Titarenko, N. N.; Demenkov, V. G.; Trykova, V. I.

    2010-07-01

    The spectra of neutrons from the ( p, n) reactions on the 208Pb and 209Bi nuclei were measured in the proton-energy range 8-11 MeV. These measurements were performed by using a time-of-flight spectrometer of fast neutrons on the basis of the pulsed tandem accelerator EGP-15 of the Institute of Physics and Power Engineering (Obninsk, Russian Federation). A high resolution and stability of the time-of-flight spectrometermade it possible to identify reliably low-lying discrete levels alongwith the continuum section of the neutron spectra. The measured data were analyzed on the basis of the statistical equilibrium and preequilibrium models of nuclear reactions. The respective calculations were performed by using the precise formalism of Hauser-Feshbach statistical theory together with the generalizedmodel of a superfluid nucleus and the back-shifted Fermi gas model for the nuclear-level density. The nuclear-level densities in 208Bi and 209Po were determined along with their energy dependences and model parameters. Our results are discussed together with available experimental data and recommendations of model systematics.

  18. The Polypyrrole/Multiwalled Carbon Nanotube Modified Au Microelectrode for Sensitive Electrochemical Detection of Trace Levels of Pb2+

    Directory of Open Access Journals (Sweden)

    Xuxing Zhu

    2017-03-01

    Full Text Available The sensitive detection of trace levels of heavy metal ions such as Pb2+ is of significant importance due to the health hazard they pose. In this paper, we present a polypyrrole (PPy/multiwalled carbon nanotube (MWCNT-modified Au microelectrode. The PPy/MWCNT composite film was electrochemically deposited on the microelectrode by cyclic voltammetry (CV. The composite film was investigated by scanning electron microscope (SEM, CV, and electrochemical impedance spectroscopy (EIS, and the results show that this film presents a uniformly distributed and web-like entangled structure and good conductivity. Differential pulse stripping voltammetry (DPSV was applied to determine trace levels of Pb2+. Experimental conditions including accumulation time and deposition potential were optimized. In optimal conditions, the PPy/MWCNT-modified microelectrode performed sensitive detection of Pb2+ within a concentration range from 1 to 100 μg·L−1, and the limit of detection was 0.65 μg·L−1 at the signal-to-noise ratio of three.

  19. Thermodynamic assessment of the Mg-Pb and Mg-Bi systems using substitutional solution and associate models for the liquid phase

    Directory of Open Access Journals (Sweden)

    Zhang F.

    2014-01-01

    Full Text Available By means of CALPHAD approach, thermodynamic assessments of the Mg-Pb and Mg-Bi systems were carried out based on the available experimental data including thermodynamic properties and phase equilibrium data. The liquid phase was described with both the substitutional solution model and the associate model, and two sets of self-consistent thermodynamic parameters for the Mg-Pb and Mg-Bi systems were obtained, respectively. It was found that the associate model can account for the experimental data more satisfactorily than the substitutional solution one, especially for the liquid phase with the short-range order behavior.

  20. Point Defects in Pb-, Bi-, and In-Doped CdZnTe Detectors: Deep-Level Transient Spectroscopy (DLTS) Measurements

    Science.gov (United States)

    Gul, R.; Keeter, K.; Rodriguez, R.; Bolotnikov, A. E.; Hossain, A.; Camarda, G. S.; Kim, K. H.; Yang, G.; Cui, Y.; Carcelen, V.; Franc, J.; Li, Z.; James, R. B.

    2012-03-01

    We studied, by current deep-level transient spectroscopy (I-DLTS), point defects induced in CdZnTe detectors by three dopants: Pb, Bi, and In. Pb-doped CdZnTe detectors have a new acceptor trap at around 0.48 eV. The absence of a VCd trap suggests that all Cd vacancies are compensated by Pb interstitials after they form a deep-acceptor complex [[PbCd]+-V{Cd/2-}]-. Bi-doped CdZnTe detectors had two distinct traps: a shallow trap at around 36 meV and a deep donor trap at around 0.82 eV. In detectors doped with In, we noted three well-known traps: two acceptor levels at around 0.18 eV (A-centers) and 0.31 eV (VCd), and a deep trap at around 1.1 eV.

  1. Improved ferroelectric and pyroelectric properties of Pb-doped SrBi{sub 4}Ti{sub 4}O{sub 15} ceramics for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Venkata Ramana, E., E-mail: venkataramanaesk@rediffmail.com [I3N-Aveiro, Department of Physics, University of Aveiro, Aveiro 3810 193 (Portugal); Graça, M.P.F.; Valente, M.A. [I3N-Aveiro, Department of Physics, University of Aveiro, Aveiro 3810 193 (Portugal); Bhima Sankaram, T. [Materials Research Laboratory, Department of Physics, Osmania University, Hyderabad 500 007 (India)

    2014-01-15

    Highlights: • Sr{sub 1−x}Pb{sub x}Bi{sub 4}Ti{sub 4}O{sub 15} (SPBT, x = 0 − 0.4) ceramics were synthesized by soft chemical method. • X-ray diffraction analysis confirmed the formation of bismuth layered structure. • SEM images showed plate like grain morphology with random orientation of plate faces. • Pb-doping resulted in improved ferroelectricity of SrBi{sub 4}Ti{sub 4}O{sub 15} ceramics. • Pb-doped SrBi{sub 4}Ti{sub 4}O{sub 15} exhibited improved pyroelectric properties with high T{sub C}. -- Abstract: Ferroelectric properties of Pb-modified strontium bismuth titanate ceramics with chemical formula Sr{sub 1−x}Pb{sub x}Bi{sub 4}Ti{sub 4}O{sub 15} (x = 0–0.4) were investigated. Polycrystalline ceramics were synthesized by soft chemical method to study the effect of Pb-doping on its physical properties. X-ray diffraction analysis revealed a bismuth layered structure for all the compounds. The doping resulted in an increased tetragonal strain and improved ferroelectric properties. Scanning electron microscope images showed plate like grain morphology with random orientation of platelets. The ferroelectric transition temperature of the ceramics increased systematically from 525 °C to 560 °C with the increase of doping concentration. The piezoelectric coefficient (d{sub 33}) of the ceramics was enhanced significantly with Pb doping, exhibiting a maximum value of 21.8 pC/N for 40 mol.% Pb-doped SBT. Pyroelectric studies carried out using the Byer–Roundy method indicated that the modified SBT ceramics are promising candidates for high temperature pyroelectric applications.

  2. Influence of Length of Opposing bi-Au Cone-Tips and Different Environment on Field Enhancement in Feed Gap

    Institute of Scientific and Technical Information of China (English)

    LI Xu-Feng; WU Shi-Fa

    2007-01-01

    Electric field enhancement distributions encountered in feed gap of opposing bi-Au cone-tips is studied using a frequency-domain three-dimensional finite element method to solve Maxwell's equations of electric field distributions. Both the influences of cone-tip length and surrounding medium on electric field enhancement are investigated. The maximal enhancement value is discussed in terms of a simple physical model based on a standing wave on the tip surface associated with the antenna effect and surface plasmon. Simulated results demonstrate the enhancement is sensitive to the tip length. By selecting a suitably matched scale according to the incident wavelength, a large enhancement value can be observed within a small focused spot between the opposing tips permitting a high spatial resolution. The relative position of the opposing tips is also found for the optimum enhancement. All of the results suggest that our configuration is suitable for the site-specific Raman spectroscopic analysis at nanoscale.

  3. Photovoltaic applications of Cu(Sb,Bi)SM (M = Ag, Pb, Pt)

    Science.gov (United States)

    Tablero, C.

    2017-04-01

    Ternary Cu-(Sb,Bi)-S compounds are great absorbents of the solar radiation with a variety of applications including optoelectronic and photovoltaic applications. The analyses of several quaternary semiconductors derived from Cu-(Sb,Bi)-S materials is carried out using first-principles density-functional theory with orbital-dependent one-electron potentials. These analyses focus on the optoelectronic properties and the potential for solar cells. The optical properties are obtained from first-principles calculations, and split into inter- and intra-shell-species contributions in order to quantify the optical transitions responsible for the absorption. The absorption coefficients are then used as criteria to evaluate the efficiencies of these materials under several sunlight concentrations. The results indicate high energy photovoltaic conversion efficiency because of the large intra shell s-p absorption of the S and Sb or Bi atomic species.

  4. The atomic size effect on hybrid inorganic-organic perovskite CH3NH3BI3 (B = Pb, Sn) from first-principles study

    Science.gov (United States)

    Chen, Qing-Yuan; Liu, Ming-Yang; Huang, Yang; Cao, Chao; He, Yao

    2017-04-01

    The inorganic-organic perovskite CH3NH3PbI3 is a hot research material owing to its outstanding performances as one light absorbing layer of solid-state dye-sensitized solar cells. In this study, we focused on the atomic size effect on CH3NH3BI3 (B = Sn, Pb), provided the best atomic size with which CH3NH3BI3 absorbs widest range of different wavelengths of light, by first-principles calculation. We found that the halogen I-p states are mainly composed of the valence band maximum (VBM) of CH3NH3BI3, and the cation B-p states are primarily composed of the conduction band minimum (CBM). Besides, the bandgap of CH3NH3BI3 decreases and absorptive capacities of different wavelengths of light expand when we reduced the size of the atom and changed B atom from Pb to Sn during the change of suitable range. From all of the above, it is discovered that when the atomic size is 20% less than the normal size, CH3NH3PbI3 has the best optical properties, and its light-absorption range is the widest among all sizes of CH3NH3BI3 compounds. All these results reveal that the stress and strain on CH3NH3BI3 change the atomic size which leads to alteration of bandgap and optical properties in high-efficiency solar cells among all CH3NH3BI3 compounds, namely we can enhance the efficiency of the inorganic-organic perovskite solar cells by setting up suitable pressure on the material in future.

  5. Seasonal variations of residence time and upper atmospheric contribution of aerosols studied with Pb-210, Bi-210, Po-210 and Be-7

    Science.gov (United States)

    Tokieda, Takayuki; Yamanaka, Kenji; Harada, Koh; Tsunogai, Shizuo

    1996-11-01

    All daily precipitation samples amounting to 196 in total were collected during the period from January 1990 to June 1991 at a station in Hakodate, Japan, and precisely analyzed for radon daughters, Pb-210, Bi-210 and Po-210. The samples collected after July 1990 were also determined for Be-7. The mean concentration and deposition rate of Pb-210 in 1990 were 0.20 Bq/1 as a mean and 288 Bq/m2/ yr, respectively, and they were a few times greater in winter due to the northwest winter monsoon. The total mean activity ratios with 95% confidence limits were 0.467±0.024 and 0.0624±0.0133 for Bi-210/Pb-210 and Po-210/Pb-210, respectively. The residence time of aerosols calculated from the Po-210/Pb-210 ratio was always longer than that calculated from the Bi-210/Pb-210 ratio. The difference is chiefly due to old aerosols derived from the upper atmosphere (probably the stratosphere), of which contribution for Pb-210 has been estimated to be 6% as a mean, or 12% in spring and 2% in early winter. Subtracting the upper atmospheric component, we have obtained the residence time of tropospheric aerosols carrying Pb-210 to be 4.8±0.3days for a whole year or 5.9±0.7days and 3.6±0.5days for the periods from February to April and from May to June, respectively. The deposition rate of Be-7 was correlated well with the upper atmospheric component of Pb-210. The larger deposition rate of Be-7 suggests that the study area is extremely effective for the removal of aerosols of stratospheric origin.

  6. Seasonal variations of residence time and upper atmospheric contribution of aerosols studied with Pb-210, Bi-210, Po-210 and Be-7

    Energy Technology Data Exchange (ETDEWEB)

    Tokieda, Takayuki; Yamanaka, Kenji; Harada, Koh; Tsunogai, Shizuo [Hokkaido Univ., Hakodate (Japan). Dept. of Chemistry

    1996-11-01

    All daily precipitation samples amounting to 196 in total were collected during the period from January 1990 to June 1991 at a station in Hakodate, Japan, and precisely analyzed for radon daughters, Pb-210, Bi-210 and Po-210. The samples collected after July 1990 were also determined for Be-7. The mean concentration and deposition rate of Pb-210 in 1990 were 0.20 Bq/l as a mean and 288 Bq/m{sup 2}/yr, respectively, and they were a few times greater in winter due to the northwest winter monsoon. The total mean activity ratios with 95% confidence limits were 0.467{+-}0.024 and 0.0624{+-}0.0133 for Bi-210/Pb-210 and Po-210/Pb-210, respectively. The residence time of aerosols calculated from the Po-210/Pb-210 ratio was always longer than that calculated from the Bi-210/Pb-210 ratio. The difference is chiefly due to old aerosols derived from the upper atmosphere (probably the stratosphere), of which contribution for Pb-210 has been estimated to be 6% as a mean, or 12% in spring and 2% in early winter. Subtracting the upper atmospheric component, we have obtained the residence time of tropospheric aerosols carrying Pb-210 to be 4.8{+-}0.3 days for a whole year or 5.9{+-}0.7 days and 3.6{+-}0.5 days for the periods from February to April and from May to June, respectively. The deposition rate of Be-7 was correlated well with the upper atmospheric component of Pb-210. The larger deposition rate of Be-7 suggests that the study area is extremely effective for the removal of aerosols of stratospheric origin. 36 refs, 7 figs, 3 tabs

  7. Low-mass lepton pair production in Pb-Au collisions at 40 A center dot GeV

    CERN Document Server

    Adamova, D; Appelshäuser, H; Belaga, V; Braun-Munzinger, P; Cherlin, A; Damjanovic, S; Dietel, T; Dietrich, L; Drees, A; Esumi, S I; Filimonov, K; Fomenko, K; Fraenkel, Zeev; Garabatos, C; Glässel, P; Hering, G; Holeczek, J; Kushpil, V; Lenkeit, B C; Maas, A; Marin, A; Milosevic, J; Milov, A; Miskowiec, D; Panebratsev, Yu A; Petchenova, O Yu; Petrácek, V; Pfeiffer, A; Rak, J; Ravinovich, I; Rehak, P; Richter, M; Sako, H; Schmitz, W; Schükraft, Jürgen; Sedykh, S; Seipp, W; Shimansky, S S; Slívova, J; Specht, H J; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Wessels, J P; Wienold, T; Windelband, B; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V

    2003-01-01

    The CERES/NA45 experiment at the CERN SPS has previously measured e **+e**- pair production in 160 A center dot GeV Pb-Au collisions. In the mass region m greater than 0.2 GeV/c**2, an enhancement of 2.7 plus or minus 0.4(stat.) plus or minus 0.5(syst.) compared to the expectation from known hadronic decay sources was observed. In the 40 A center dot GeV data taken in 1999, an enhancement is again found; a preliminary analysis gives an even larger value of 5.0 plus or minus 1.3(stat.). The results are compared to theoretical model calculations based on pi**+ pi**- annihilation with a modified rho- propagator; they may be related to chiral symmetry restoration. 17 Refs.

  8. Evaporation residue cross sections from complete fusion of {sup 16}O with {sup 197}Au, {sup 208}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, K.T.; Caraley, A.L.; Fineman, B.J. [and others

    1993-04-01

    Fusion-evaporation excitation functions for complete fusion of {sup 16}O with {sup 197}Au and {sup 208}Pb have been measured from the barrier up to excitation energies of about 100 MeV. Using the pulsed {sup 16}O beam from the Stony Brook LINAC, the very slow evaporation residues (ER`s) were separated in an electrostatic deflector system and identified in an array of three surface barrier detectors by their time of flight and energy. While the ER cross sections in the vicinity of the fusion barrier allow the extraction of important statistical model parameters such as fission barrier heights, data at higher excitation energies can yield insight into processes beyond the statistical model regime. The results will be discussed with respect to both aspects.

  9. Scale-dependence of transverse momentum correlations in Pb-Au collisions at 158A GeV/c

    CERN Document Server

    Adamová, D; Antonczyk, D; Appelshäuser, H; Belaga, V; Bielcikova, S; Braun-Munzinger, P; Busch, O; Cherlin, A; Damjanovic, S; Dietel, T; Dietrich, L; Drees, A; Dubitzky, W; Esumi, S I; Filimonov, K; Fomenko, K; Fraenkel, Zeev; Garabatos, C; Glässel, P; Holeczek, J; Kushpil, V; Maas, A; Marín, A; Milosevic, J; Milov, A; Miskowiec, D; Panebratsev, Yu A; Petchenova, O; Petracek, V; Pfeiffer, A; Ploskon, M; Radomski, S; Rak, acn J; Ravinovich, I; Rehak, P; Sako, H; Schmitz, W; Sedykh, S; Shimansky, S; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Tsiledakis, G; Wessels, J P; Wienold, T; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V

    2008-01-01

    We present results on transverse momentum correlations of charged particle pairs produced in Pb-Au collisions at 158$A$ GeV/$c$ at the Super Proton Synchrotron. The transverse momentum correlations have been studied as a function of collision centrality, angular separation of the particle pairs, transverse momentum and charge sign. We demonstrate that the results are in agreement with previous findings in scale-independent analyses at the same beam energy. Employing the two-particle momentum correlator $$ and the cumulative $p_t$ variable $x(p_t)$, we identify, using the scale-dependent approach presented in this paper, different sources contributing to the measured correlations, such as quantum and Coulomb correlations, elliptic flow and mini-jet fragmentation.

  10. Antiproton Production in 11.5A GeV/c Au+Pb Nucleus-Nucleus Collisions

    Energy Technology Data Exchange (ETDEWEB)

    De Cataldo, G.; Giglietto, N.; Raino, A.; Spinelli, P. [University of Bari/INFN, Bari (Italy); Dover, C.B. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Huang, H.Z. [University of California at Los Angeles, Los Angeles, California 90024 (United States); Hill, J.C.; Libby, B.; Wohn, F.K. [Iowa State University, Ames, Iowa 50011 (United States); Rabin, M.S. [University of Massachusetts, Amherst, Massachusetts 01003 (United States); Haridas, P.; Pless, I.A.; Van Buren, G. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Armstrong, T.A.; Lewis, R.A.; Reid, J.D.; Smith, G.A.; Toothacker, W.S. [Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Davies, R.; Hirsch, A.S.; Porile, N.T.; Rimai, A.; Scharenberg, R.P.; Srivastava, B.K.; Tincknell, M.L. [Purdue University, West Lafayette, Indiana 47907 (United States); Greene, S.V. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Bennett, S.J.; Cormier, T.M.; Dee, P.; Fachini, P.; Kim, B.; Li, Q.; Li, Y.; Munhoz, M.G.; Pruneau, C.A.; Wilson, W.K.; Zhao, K. [Wayne State University, Detroit, Michigan 48201 (United States); Barish, K.N.; Bennett, M.J.; Chikanian, A.; Coe, S.D.; Diebold, G.E.; Finch, L.E.; George, N.K.; Kumar, B.S.; Lajoie, J.G.; Majka, R.D.; Nagle, J.L.; Pope, J.K.; Rotondo, F.S.; Sandweiss, J.; Slaughter, A.J.; Wolin, E.J. [Yale University, New Haven, Connecticut 06520 (United States)

    1997-11-01

    We present the first results from the E864 Collaboration on the production of antiprotons in 10{percent} central 11.5A GeV /c Au+Pb nucleus collisions at the Brookhaven Alternating Gradient Synchrotron. We report invariant multiplicities for antiproton production in the kinematic region 1.4{lt}y{lt}2.2 and 50{lt} p{sub T}{lt} 300 MeV/c , and compare our data with a first collision scaling model and previously published results from the E878 Collaboration. The differences between the E864 and E878 antiproton measurements and the implications for antihyperon production are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  11. Oxidation and reduction kinetics of eutectic SnPb, InSn, and AuSn: a knowledge base for fluxless solder bonding applications

    DEFF Research Database (Denmark)

    Kuhmann, Jochen Friedrich; Preuss, A.; Adolphi, B.;

    1998-01-01

    For microelectronics and especially for upcoming new packaging technologies in micromechanics and photonics fluxless, reliable and economic soldering technologies are needed. In this article, we consequently focus on the oxidation and reduction kinetics of three commonly used eutectic solder allo...... and reflowed AuSn(80/20) and SnPb(60/40) after the introduction of H2...

  12. Oxygen Adsorption-Desorption Behavior and Superconducting Properties of High-Tc Bi(Pb)-Sr-Ca-Cu-O

    Science.gov (United States)

    Miura, Norio; Suzuta, Hiroki; Deshimaru, Yuichi; Shimizu, Youichi; Sakashita, Hirofumi; Yamazoe, Noboru

    1989-07-01

    Temperature-programmed desorption (TPD) chromatograms revealed that a small amount of oxygen was desorbed from high-Tc Bi(Pb)-Sr-Ca-Cu-O (BPSCCO) in the temperature range from ca. 350 to ca. 650°C prior to a steep increase of oxygen desorption in the higher temperature range. The Tc of BPSCCO was significantly lowered with the progress of oxygen desorption especially in the former temperature range, and was restored to the original level when the desorbed oxygen was recovered. With no corresponding changes in X-ray powder diffraction pattern being detected, the oxygen desorbed below ca. 650°C was concluded to have strong relevance to the superconductivity of BPSCCO.

  13. Dielectric properties of BiFeO3-PbTiO3 thin films prepared by PLD

    Institute of Scientific and Technical Information of China (English)

    CHEN Rui; YU Sheng-wen; ZHANG Guan-jun; CHENG Jin-rong; MENG Zhong-yan

    2006-01-01

    BiFeO3-PbTiO3 (BFO-PT) thin films were prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition (PLD) technique under different oxygen pressures. The structures of the films were characterized by means of XRD. The current densities were performed to check the conductivity of the films. The dielectric constant and loss factor (tanδ) of the films were measured. The results show that the BFO-PT layers are mainly perovskite structured:the film deposited under 6.665 Pa exhibits low leakage current,low dielectric loss (0.017-0.041) and saturated hysteresis loop with polarization (Pr) value and coercive field (Ec) of 3 μC/cm2 and 109 kV/cm.

  14. Mineralogical data on angelaite, Cu2AgPbBiS4, from the Los Manantiales District, Chubut, Argentina

    DEFF Research Database (Denmark)

    Topa, D.; Paar, W.H.; Putz, H.

    2010-01-01

    , native gold and galena; less common associates are aikinite, wittichenite, miharaite and cervelleite. Angelaite forms subhedral, commonly oriented inclusions in galena; these may attain a size of up to 200 3 50 mm. The mineral is grey in color with a brownish tint, opaque, and lacks internal reflections...... is strongly anisotropic, with rotation tints in shades of pale grey, deep green and deep blue. We provide the measured values of reflectance in air and oil. The average of 23 electron-microprobe analyses is: Cu 16.7(3), Ag 13.4(2), Pb 27.8(6), Bi 26.6(5), S 16.0(2), total 100.5(5) wt.%, equivalent to Cu2.07Ag...

  15. Investigation of evaporation characteristics of polonium and its lighter homologues selenium and tellurium from liquid Pb-Bi-eutecticum

    CERN Document Server

    Neuhausen, J; Eichler, B

    2004-01-01

    The evaporation behaviour of polonium and its lighter homologues selenium and tellurium dissolved in liquid Pb-Bi-eutecticum (LBE) has been studied at various temperatures in the range from 482 K up to 1330 K under Ar/H2 and Ar/H2O-atmospheres using γ-ray spectroscopy. Polonium release in the temperature range of interest for technical applications is slow. Within short term (1h) experiments measurable amounts of polonium are evaporated only at temperatures above 973 K. Long term experiments reveal that a slow evaporation of polonium occurs at temperatures around 873 K resulting in a fractional polonium loss of the melt around 1% per day. Evaporation rates of selenium and tellurium are smaller than those of polonium. The presence of H2O does not enhance the evaporation within the error limits of our experiments. The thermodynamics and possible reaction pathways involved in polonium release from LBE are discussed.

  16. Preliminary safety analysis of Pb-Bi cooled 800 MWt modified CANDLE burn-up scheme based fast reactors

    Science.gov (United States)

    Su'ud, Zaki; Sekimoto, H.

    2014-09-01

    Pb-Bi Cooled fast reactors with modified CANDLE burn-up scheme with 10 regions and 10 years cycle length has been investigated from neutronic aspects. In this study the safety aspect of such reactors have been investigated and discussed. Several condition of unprotected loss of flow (ULOF) and unprotected rod run-out transient over power (UTOP) have been simulated and the results show that the reactors excellent safety performance. At 80 seconds after unprotected loss of flow condition, the core flow rate drop to about 25% of its initial flow and slowly move toward its natural circulation level. The maximum fuel temperature can be managed below 1000°C and the maximum cladding temperature can be managed below 700°C. The dominant reactivity feedback is radial core expansion and Doppler effect, followed by coolant density effect and fuel axial expansion effect.

  17. Peltier-effect in the mixed state of (Bi, Pb)2Sr2Ca2Cu3O

    Science.gov (United States)

    Galffy, M.; Hohn, Ch.; Freimuth, A.

    We present measurements of the Peltier-effect in the mixed state of Bi1.76Pb0.24Sr2Ca2Cu3O. The Peltier-coefficient broadens in a magnetic field quite similar to the resistivity and the thermopower. Comparison with the thermopower shows that Onsagers relation holds well. The occurrence of the Peltier-heat in the mixed state well below Tc implies that the electric current is accompanied by a large heat current. We show that the vortex contribution to the Peltier-heat is negligibly small. Therefore the heat current has to be attributed to normal quasiparticle excitations. Our results indicate that this quasiparticle contribution to the heat current remains large even at temperatures far below Tc.

  18. A study of the heat treatment time, temperature and ramp rate on the transport current properties and Bi-2223 grain growth in (Bi,Pb)2223/Ag superconducting tapes

    CERN Document Server

    Young, E A

    2002-01-01

    The Bi-2223 phase formation in (Bi,Pb)2223/Ag tapes is known to be via a Pb rich liquid phase, the control of the wetting properties and the phase volume of liquid phase in the early hours of sintering can substantially improve the transport current of the final sintered tape. The phase volume of liquid phase, characterised by the formation of the Bi sub 2 (Sr sub 1 sub . sub 6 Ca sub 0 sub . sub 4)CuO sub 6 , (Bi-2201), phase, was observed to depend on the heat treatment temperature and atmosphere. The volume of secondary phases, (Cu sub 2 O, Cu-free phase, and Bi sub 2 (Sr sub 1 sub . sub 6 Ca sub 0 sub . sub 4)CuO sub 6), in the sintered Bi-2223 microstructure is shown to be sensitive to the sintering heating rate, and this is thought to be related to the wetting properties of the liquid phase. For an optimum transport critical current, (77K, self field), the heat treatment temperature and the heating rate are inter-dependent parameters, the heating rate only increasing the transport current of tapes heat ...

  19. Ag doped (Bi1.6Pb0.4Sr2CaCu2O8+δ textured rods

    Directory of Open Access Journals (Sweden)

    Díez, J. C.

    2008-06-01

    Full Text Available In this work, superconducting samples of (Bi1.6Pb0.4Sr2CaCu2O8+δ with Ag additions have been studied. (Bi1.6Pb0.4Sr2CaCu2O8+δ + x wt.% Ag (with x = 0, 1 and 3 powders were synthesized using a sol-gel method. The obtained powders were used as precursors to fabricate long textured cylindrical bars through a floating zone melting method. A drastic change on the microstructure has been found when comparing with undoped Bi2Sr2CaCu2O8+δ samples. The results showed that electrical resistivity at room temperature, critical current as well as flexural strength are improved when Ag is added to these Pb doped samples, while critical temperature does not change. On the other hand, it has been found that samples with composition (Bi1.6Pb0.4Sr2CaCu2O8+δ + Ag shown E-I curves with very high sharpness values on the zone of the superconducting to normal transition, reaching n-values (E∼In as high as 45 at 65K.Se han preparado polvos cerámicos de composición (Bi1.6Pb0.4Sr2CaCu2O8+δ + x % Ag en peso (con x = 0, 1 y 3 mediante un proceso sol-gel. Estos polvos se han utilizado para fabricar precursores que se texturaron por medio del método de fusión zonal flotante. Se ha encontrado un gran cambio en la microestructura cuando se compara con muestras de composición pura Bi2Sr2CaCu2O8+δ. Tanto la resistividad eléctrica a temperatura ambiente, como la corriente crítica, así como la resistencia a flexión se mejoran cuando la Ag se adiciona a estas muestras dopadas con Pb, mientras que no se observa cambio en la temperatura crítica. Por otra parte, se ha encontrado que las muestras de composición (Bi1.6Pb0.4Sr2CaCu2O8+δ + Ag presentan una gran pendiente de la curva E-I en la zona de transición entre el estado superconductor y el estado normal. Con estas composiciones, se han encontrado valores de n (E∼In de hasta 45 a 65K.

  20. Superconducting and mechanical properties of the bulk Bi(pb)SCCO system prepared via solid state and ammonium nitrate precipitation methods

    Science.gov (United States)

    Safran, S.; Kılıçarslan, E.; Ozturk, H.; Alp, M.; Akdogan, M.; Asikuzun, E.; Ozturk, O.; Kılıç, A.

    2015-09-01

    We have investigated the effect of preparation method on superconducting and mechanical properties of Bi(Pb)-2223 bulk samples using Bi1.85Pb0.35Sr2Ca2Cu3O10±y stoichiometry. Solid-state reaction and ammonium nitrate precipitation methods have been used for fabrication of the bulk samples. In addition, the effect of annealing time on BSCCO samples have been studied. Structural, electrical, magnetic and microhardness analyses of samples are performed by the X-ray powder diffraction (XRD), the Scanning Electron Microscopy (SEM), DC resistivity, AC susceptibility and Vickers microhardness test. The critical transition temperature, phase purity, surface morphology and crystallinity of the prepared bulk samples are compared with each other. Elasticity (E), brittleness (Bi), fracture toughness (KIC) and yield strength (Y) values are also determined according to annealing time, applied load and production parameters of materials.

  1. Variation of Piezoelectric properties and mechanisms across the relaxor-like/Ferroelectric continuum in BiFeO3- (K0.5Bi0.5)TiO3-PbTiO3 ceramics.

    Science.gov (United States)

    Bennett, James; Shrout, Thomas R; Zhang, Shujun; Owston, Heather E; Stevenson, Tim J; Esat, Faye; Bell, Andrew J; Comyn, T P

    2015-01-01

    1- x - y)BiFeO3-x(K0.5Bi0.5)TiO3-yPbTiO3 (BFKBT- PT) piezoelectric ceramics were investigated across the compositional space and contrasted against the xBiFeO3- (1-x)(K0.5Bi0.5)TiO3 (BF-KBT) system, whereby a range of relaxor-like/ferroelectric behavior was observed. Structural and piezoelectric properties were closely related to the PbTiO3 concentration; below a critical concentration, relaxor-like behavior was identified. The mechanisms governing the piezoelectric behavior were investigated with structural, electrical, and imaging techniques. X-ray diffraction established that longrange non-centrosymmetric crystallographic order was evident above a critical PbTiO3 concentration, y > 0.1125. Commensurate with the structural analysis, electric-field-induced strain responses showed electrostrictive behavior in the PbTiO3-reduced compositions, with increased piezoelectric switching in PbTiO3-rich compositions. Positive-up-negative-down (PUND) analysis was used to confirm electric-field-induced polarization measurements, elucidating that the addition of PbTiO3 increased the switchable polarization and ferroelectric ordering. Piezoresponse force microscopy (PFM) of the BF-KBT-PT system exhibited typical domain patterns above a critical PbTiO3 threshold, with no ferroelectric domains observed in the BF-KBT system in the pseudocubic region. Doping of BiFeO3-PbTiO3 has been unsuccessful in the search for hightemperature materials that offer satisfactory piezoelectric properties; however, this system demonstrates that the partial substitution of alternative end-members can be an effective method. The partial substitution of PbTiO3 into BF-KBT enables long-range non-centrosymmetric crystallographic order, resulting in increased polar order and TC, compared with the pseudocubic region. The search for novel high-temperature piezoelectric ceramics can therefore exploit the accommodating nature of the perovskite family, which allows significant variance in chemical and physical

  2. Transport Phenomena in the Vapor-phase PbTe-Bi2Te3 Condensates on Sital

    Directory of Open Access Journals (Sweden)

    D.M. Freik

    2013-10-01

    Full Text Available Dependences of the structural characteristics and electrical properties of thin films of PbTe-Bi2Te3 solid solutions with compositions of 1,3,5 ml. % of Bi2Te3 deposited in an open vacuum on the sital substrates on their thickness d  (0,2-2 microns were studied. The effective mean free path  of charge carriers is defined and the dominant mechanism of scattering is found. The values of thermoelectric parameters of the near-surface layers are estimated within the two-layer Petritz model. It is stablished that condensate is characterized by a stable n-type conductivity, and there is a diffuse scattering on the surface that conditions a significant decrease in the magnitude of mobility (s, conductivity (s, and increase in the Seebeck coefficient (Ss with respect to the film volume. The obtained results are explained by acceptor influence of atmospheric oxygen and throttling of charge carriers on potential barriers of the interfaces.

  3. Enhanced High Temperature Piezoelectrics Based on BiScO3-PbTiO3 Ceramics

    Science.gov (United States)

    Sehirlioglu, Alp; Sayir, Ali; Dynys, Fred

    2009-01-01

    High-temperature piezoelectrics are a key technology for aeronautics and aerospace applications such as fuel modulation to increase the engine efficiency and decrease emissions. The principal challenge for the insertion of piezoelectric materials is the limitation on upper use temperature which is due to low Curie-Temperature (TC) and increasing electrical conductivity. BiScO3-PbTiO3 (BS-PT) system is a promising candidate for improving the operating temperature for piezoelectric actuators due to its high TC (greater than 400 C). Bi2O3 was shown to be a good sintering aid for liquid phase sintering resulting in reduced grain size and increased resistivity. Zr doped and liquid phase sintered BS-PT ceramics exhibited saturated and square hysteresis loops with enhanced remenant polarization (37 microC per square centimeter) and coercive field (14 kV/cm). BS-PT doped with Mn showed enhanced field induced strain (0.27% at 50kV/cm). All the numbers indicated in parenthesis were collected at 100 C.

  4. EFFECT OF LASER INPUT ENERGY ON AuSnx INTERMETALLIC COMPOUNDS FORMATION IN SOLDER JOINTS WITH DIFFERENT THICKNESS OF Au SURFACE FINISH ON PADS

    Institute of Scientific and Technical Information of China (English)

    W.Liu; C.Q.Wang; Y.H.Tian; M.Y.Li

    2008-01-01

    Formation of AuSnx intermetallic compounds (IMCs) in laser reflowed solder joints was investigated. The results showed that few IMCs formed at the solder/0.1 μm Au interface. Needlelike AuSn4 IMCs were observed at the solder/0.5 μm Au interface.In Sn-2.0Ag-0.75Cu-3.0Bi and Sn-3.5Ag-O.75Cu solder joints, when the laser input energy was increased, AuSn4 IMCs changed from a layer to needlelike or dendritic distribution at the solder/0.9 μm Au interface. As for the solder joints with 4.0 μm thickness of Au surface finish on pads, AuSn4 , AuSn2, AuSn IMCs, and Au2 Sn phases formed at the interface. Moreover, the content of AuSnx IMCs, such as, AuSn4 and AuSn2, which contained high Sn concentration, would become larger as the laser input energy increased. In the Sn-37Pb solder joints with 0.9 μm or 4.0 μm thickness of the Au surface finish on pads, AuSn4 IMCs were in netlike distribution. The interspaces between them were filled with Pb-rich phases.

  5. Two-proton correlations from 14.6{ital A} GeV/{ital c} Si+Pb and 11.5{ital A} GeV/{ital c} Au+Au central collisions

    Energy Technology Data Exchange (ETDEWEB)

    David, G.; Ludlam, T.W.; McCorkle, S.; OBrien, E.; Takai, H.; Woody, C.L. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Braun-Munzinger, P.; Herrmann, N.; Hong, B.; Miskowiec, D. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany); Cole, J.; Drigert, M.; Reber, E. [Idaho National Engineering Laboratory, Idaho Falls, Idaho 83402 (United States); Barrette, J.; Dai, Y.; Filimonov, K.; Gilbert, S.; Lacasse, R.; Mark, S.K.; Rosati, M.; Wang, G. [McGill University, Montreal (Canada); Cleland, W.E.; Clemen, M.; Sonnadara, U.; Voloshin, S.; Zhang, Z. [University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Bersch, R.; Chang, W.C.; Dee, J.; Johnson, S.C.; Hemmick, T.K.; Jiang, C.L.; Kwon, Y.; Panitkin, S.Y.; Pantuev, V.S.; Piazza, T.; Pollack, M.; Rao, M.N.; Sedykh, S.; Vongpaseuth, T.; Xu, N.; Zhang, Y.; Zou, C. [State University of New York at Stony Brook, Stony Brook, New York 11794 (United States); Dietzsch, O.; daSilva, N.C.; Takagui, E.M. [University of Sao Paulo, Sao Paulo (Brazil); Bellwied, R.; Bennett, S.; Cormier, T.M.; Hall, J.R.; Li, Q.; Matheus, R.; Murgatroyd, J.T.; Pruneau, C.; Sheen, J. [Wayne State University, Detroit, Michigan 48202 (United States); Stachel, J.; Voloshin, S.; Wessels, J.P. [Physikalisches Institut der Universitaet Heidelberg, Heidelberg (Germany)

    1999-11-01

    Two-proton correlation functions have been measured in Si+Pb collisions at 14.6A GeV/c and Au+Au collisions at 11.5{ital A} GeV/{ital c} by the E814/E877 Collaboration. Data are compared with predictions of the transport model RQMD and the source size is inferred from this comparison. Our analysis shows that, for both reactions, the characteristic size of the system at freeze-out exceeds the size of the projectile, suggesting that the fireball created in the collision has expanded. For Au+Au reactions, the observed centrality dependence of the two-proton correlation function implies that more central collisions lead to larger source sizes. {copyright} {ital 1999} {ital The American Physical Society}

  6. Strong electronic consequences of intercalation in cuprate superconductors: the case of a trigonal planar AuI(3) complex stabilized in the Bi(2)Sr(2)CaCu(2)O(y) lattice.

    Science.gov (United States)

    Munzarová, Markéta L; Hoffmann, Roald

    2002-05-15

    Recently, a molecular AuI(3) complex was stabilized in the interlayer space of the Bi(2)Sr(2)CaCu(2)O(y) (Bi2212) high-T(c) superconducting phase, adopting an exceptional D(3)(h) structure (Choy, J.-H.; et al. J. Phys.Chem. B 2000, 104, 7273). If the gold were formally Au(III), a strong Jahn-Teller distortion to T- and Y-shaped structures would be expected. In this work, we try to understand the structural preferences of AuI(3) in both the gas phase and the Bi2212 lattice, as well as the influence of the AuI(3) intercalation on the superconductor lattice. What we think actually happens is that there is an effective electron transfer from the s-type Bi lone pair to the gold, increasing the formal oxidation state of Bi from +3 to +5 and decreasing that of Au from +3 to +1. A trigonal Au(I) trihalide is just fine. The DFT results confirm in the Bi-rich regions the same kind of electron transfer as encountered on the EHT level of theory, but they reveal additional complexities of the problem. The effect of the Bi to intercalating molecule electron transfer on the cuprate layer may be important, quite apart from this specific example, in tuning superconductivity in the cuprates.

  7. Cap effect of (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} thick films during post-annealing process

    Energy Technology Data Exchange (ETDEWEB)

    Tokuda, T. [Department of Electrical and Electronic Engineering, Tottori University, 4-101, Koyama-Minami, Tottori 680-8552 (Japan); Honda, S., E-mail: b03t3052@faradayele.tottori-u.ac.j [Department of Electrical and Electronic Engineering, Tottori University, 4-101, Koyama-Minami, Tottori 680-8552 (Japan); Kinoshita, K.; Kishida, S. [Department of Electrical and Electronic Engineering, Tottori University, 4-101, Koyama-Minami, Tottori 680-8552 (Japan)

    2009-10-15

    We prepared (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} (BiPb-2223) thick films on MgO substrates by a spin coating method and investigated their superconducting property. The surface of BiPb-2223 thick films was capped with MgO, Ag or BiPb-2223/MgO during sintering process. From the results of X-ray diffraction patterns and resistance-temperature characteristics, we found that the caps of MgO and Ag were useful for obtaining the 30 mum-BiPb-2223 thick films with the T{sub c} above 100 K. Although the T{sub c} of the thick films with the thickness less than 5 mum decreased, the T{sub c} of the BiPb-2223 films with the thickness less than 5 mum was improved by use of the BiPb-2223/MgO cap.

  8. Effect of Substitutional Pb Doping on Bipolar and Lattice Thermal Conductivity in p-Type Bi0.48Sb1.52Te3

    Directory of Open Access Journals (Sweden)

    Hyun-sik Kim

    2017-07-01

    Full Text Available Cation substitutional doping is an effective approach to modifying the electronic and thermal transports in Bi2Te3-based thermoelectric alloys. Here we present a comprehensive analysis of the electrical and thermal conductivities of polycrystalline Pb-doped p-type bulk Bi0.48Sb1.52Te3. Pb doping significantly increased the electrical conductivity up to ~2700 S/cm at x = 0.02 in Bi0.48-xPbxSb1.52Te3 due to the increase in hole carrier concentration. Even though the total thermal conductivity increased as Pb was added, due to the increased hole carrier concentration, the thermal conductivity was reduced by 14–22% if the contribution of the increased hole carrier concentration was excluded. To further understand the origin of reduction in the thermal conductivity, we first estimated the contribution of bipolar conduction to thermal conductivity from a two-parabolic band model, which is an extension of the single parabolic band model. Thereafter, the contribution of additional point defect scattering caused by Pb substitution (Pb in the cation site was analyzed using the Debye–Callaway model. We found that Pb doping significantly suppressed both the bipolar thermal conduction and lattice thermal conductivity simultaneously, while the bipolar contribution to the total thermal conductivity reduction increased at high temperatures. At Pb doping of x = 0.02, the bipolar thermal conductivity decreased by ~30% from 0.47 W/mK to 0.33 W/mK at 480 K, which accounts for 70% of the total reduction.

  9. Quantification of the {sup 214} Pb and {sup 214} Bi decay products before and after to reach the secular equilibria with the {sup 226} Ra; Cuantificacion de los productos de decaimiento {sup 214} Pb y {sup 214} Bi antes y despues de alcanzar el equilibrio secular con el {sup 226} Ra

    Energy Technology Data Exchange (ETDEWEB)

    Quintero P, E.; Rojas M, V.P.; Cervantes N, M.L.; Gaso P, M.I. [Gerencia de Seguridad Radiologica, ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    In this work a comparison between the {sup 226} Ra concentration and its decay products ({sup 214} Pb and {sup 214} Bi) in soil samples is presented before and after that the decay mentioned products reach the equilibria with the radium. Moreover, the obtained daughter/father ratio is presented; and the correction factor for the calculus of the {sup 214} Pb and {sup 214} Bi quantification without being necessary to wait until that the secular equilibria has been established. For the quantification of the concentration of the three radionuclides the gamma spectrometry technique was used. (Author)

  10. Pb-Sr-Nd isotopes in surficial materials at the Pebble Porphyry Cu-Au-Mo Deposit, Southwestern Alaska: can the mineralizing fingerprint be detected through cover?

    Science.gov (United States)

    Ayuso, Robert A.; Kelley, Karen D.; Eppinger, Robert G.; Forni, Francesca

    2013-01-01

    The Cretaceous Pebble porphyry Cu-Au-Mo deposit is covered by tundra and glacigenic sediments. Pb-Sr-Nd measurements were done on sediments and soils to establish baseline conditions prior to the onset of mining operations and contribute to the development of exploration methods for concealed base metal deposits of this type. Pebble rocks have a moderate range for 206Pb/204Pb = 18.574 to 18.874, 207Pb/204Pb = 15.484 to 15.526, and 208,Pb/204Pb = 38.053 to 38.266. Mineralized granodiorite shows a modest spread in 87Sr/86Sr (0.704354–0.707621) and 143Nd/144Nd (0.512639–0.512750). Age-corrected (89 Ma) values for the granodiorite yield relatively unradiogenic Pb (e.g., 207Pb/204Pb 87Sr/86Sr, and positive values of ɛNd (1.00–4.52) that attest to a major contribution of mantle-derived source rocks. Pond sediments and soils have similar Pb isotope signatures and 87Sr/86Sr and 143Nd/144Nd values that resemble the mineralized granodiorites. Glacial events have obscured the recognition of isotope signatures of mineralized rocks in the sediments and soils. Baseline radiogenic isotope compositions, prior to the onset of mining operations, reflect natural erosion, transport and deposition of heterogeneous till sheets that included debris from barren rocks, mineralized granodiorite and sulfides from the Pebble deposit, and other country rocks that pre- and postdate the mineralization events. Isotopic variations suggest that natural weathering of the deposit is generally reflected in these surficial materials. The isotope data provide geochemical constraints to glimpse through the extensive cover and together with other geochemical observations provide a vector to concealed mineralized rocks genetically linked with the Pebble deposit.

  11. Manufacture of Bi, Pb-Sr-Ca-Cu-O pellet disc using wet method

    Science.gov (United States)

    Hendrik, Sebleku, Pius; Yudanto, Sigit Dwi; Siswayanti, Bintoro; Pramono, Andika Widya; Imaduddin, Agung

    2016-04-01

    A confirmation of favorable properties of pellet disc of HTSBPSCCO is required in order to optimally do subsequent process of powder-in-tube (PIT) fabricated intosuperconductor wires. Wet method is a simple method in fabricating superconductor wire when it comes to mass production. In order to optimize this method, temperature parameter holds a decisive role in the formation of the 2223 phase of BPSCCO. We have synthesized two samples using wet method with the sintering temperature of 855°C and 865°C for 90 hours in air atmosphere.XRD analysis points out the formation of Bi-2223 phase of the sample with the sintering temperature of 855°C, whereas Bi-2212 phase is detected in the one with the sintering temperature of 865°C. The surface morphology of both samples are layers-like. According to temperature dependence of resistivity measurement results, both samples have superconductivity behavior below critical temperature (Tc). The former one (Tsintering = 855°C) has conductive-like behavior above Tcof whichits resistivity starts to drop at 112K and reaches zero resistivity at 78K, and the latter one (Tsintering = 865°C)has semiconductor-like behavior of whichits resistivity starts to drop at 82K and then reaches zero resistivity at 48K.

  12. Crystal and electronic structure of BiTeI, AuTeI, and PdTeI compounds: A dispersion-corrected density-functional study

    OpenAIRE

    Güler-Kılıç, Sümeyra; Kılıç, Çetin

    2015-01-01

    Semilocal and dispersion-corrected density-functional calculations have been performed to study the crystal structure, equation of state, and electronic structure of metal tellurohalides with chemical formula MeTeI where Me=Bi, Au, or Pd. A comparative investigation of the results of these calculations is conducted which reveals the role of van der Waals attraction. It is shown that the prediction of crystal structure of metal tellurohalides is systematically improved thanks to the inclusion ...

  13. Influence of gold diffusion-doped on phase formation, superconducting and microstructure properties of Bi1.8Pb0.35Sr1.9Ca2.1Cu3Oy superconductors

    Science.gov (United States)

    Ozturk, O.; Akdogan, M.; Terzioglu, C.; Gencer, A.

    2009-03-01

    We report on low-field magnetic properties of gold diffusion-doped Bi1.8Pb0.35Sr1.9Ca2.1Cu3Oy superconducting bulk samples by performing ac susceptibility measurements. The undoped samples were prepared by the standard solid-state reaction method. Doping of Bi1.8Pb0.35Sr1.9Ca2.1Cu3Oy was carried out by means of Au-diffusion during sintering from an evaporated gold film on pellets. To investigate the effect of gold-diffusion and diffusion-annealing duration on transport, magnetic and microstructure properties of the superconducting samples we performed magnetoresistivity, scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. The ac susceptibility as a function of temperature measurements were carried out at different values of the ac magnetic field amplitudes (Hac) in the range between 20A/m and 320 A/m for 211 Hz. The imaginary part of ac susceptibility measurements is used to calculate intergranular critical current density Jc(Tp) using the Bean Model. Jc(Tp) is seen to increase from 60 A cm-2 to 90 A cm-2 with increasing diffusion-annealing time from 10 h to 50 h. The peak temperature, Tp, in the imaginary part of the ac susceptibility is shifted to a lower temperature with decreasing diffusion-annealing duration as well as increasing ac magnetic fields. The force pinning density (αjj (0)) increased with increasing diffusion annealing time. The value of Tc in gold-diffused samples, in comparison with the undoped samples, increased from 100 ± 0.2 K to 104 ± 0.2 K. It was observed that the value of Tc-offset of the gold-doped samples enhanced with further increasing diffusion-annealing duration. XRD patterns and SEM micrographs are used to obtain information about Bi-2223 phase ratio, lattice parameters and grain size of the samples. Gold doping enhanced the formation high-Tc phase and increased the grain size. The possible reasons for the observed improvements in transport, microstructure and magnetic properties due to Au diffusion and

  14. Charge exchange and X-ray emission in 70 MeV/u Bi-Au collisions

    Energy Technology Data Exchange (ETDEWEB)

    Verma, P. [GSI, D-64291 Darmstadt (Germany) and Vaish College, Rohtak 124 001 (India) and J. Liebig University, D-35392 Giessen (Germany)]. E-mail: P.Verma@gsi.de; Mokler, P.H. [GSI, D-64291 Darmstadt (Germany); JMI University, New Delhi 110 025 (India); Braeuning-Demian, A. [GSI, D-64291 Darmstadt (Germany); Braeuning, H. [JMI University, New Delhi 110 025 (India); Berdermann, E. [GSI, D-64291 Darmstadt (Germany); Chatterjee, S. [GSI, D-64291 Darmstadt (Germany); Gumberidze, A. [GSI, D-64291 Darmstadt (Germany); Hagmann, S. [J.W. Goethe University, D-60486 Frankfurt (Germany); Kozhuharov, C. [GSI, D-64291 Darmstadt (Germany); Orsic-Muthig, A. [GSI, D-64291 Darmstadt (Germany); Reuschl, R. [J.W. Goethe University, D-60486 Frankfurt (Germany); Schoeffler, M. [J.W. Goethe University, D-60486 Frankfurt (Germany); Spillmann, U. [GSI, D-64291 Darmstadt (Germany); Stoehlker, Th. [GSI, D-64291 Darmstadt (Germany); Stachura, Z. [Institute for Nuclear Physics, PL-31-342 Cracow (Poland); Tashenov, S. [GSI, D-64291 Darmstadt (Germany); Wahab, M.A. [Vaish College, Rohtak 124 001 (India)

    2005-07-01

    Charge exchange and X-ray emission for 70 MeV/u highly charged ions of Bi {sup q+} [77 q 82] colliding with thin Au targets [21 t in {mu}g/cm{sup 2} 225] were measured at the heavy ion synchrotron SIS at GSI. For the innermost shells this beam energy implies a quasiadiabatic collision regime. The charge state distribution of the emerging ions was measured by a position sensitive CVD-diamond detector after being analyzed by a magnet spectrometer. Charge exchange cross sections have been deduced from the target thickness dependence of the charge state distribution. Electron capture at distant collision dominates completely over ionization at close collision. The X-ray emission from the collision partners were measured by solid state detectors, Ge(i). The K X-ray emission for closed and open incoming projectile K vacancies gives access to vacancy transfer in the superheavy quasi-molecule transiently formed during collision for the innermost shells.

  15. Tailoring the structure and piezoelectric properties of BiFeO3-(K0.5Bi0.5)TiO3-PbTiO3 ceramics for high temperature applications

    Science.gov (United States)

    Bennett, J.; Bell, A. J.; Stevenson, T. J.; Comyn, T. P.

    2013-10-01

    There is a growing requirement for piezoelectric materials and systems which can operate in extreme environments, for example, oil & gas, and aerospace. Here, we present the high temperature BiFeO3-K0.5Bi0.5TiO3-PbTiO3 (BF-KBT-PT) polycrystalline perovskite system. X-ray diffraction, impedance analysis, and Berlincourt measurements reveal a large region of phase coexistence, which can be tailored to optimise performance; Tc and the tetragonal spontaneous strain correlate strongly with the PbTiO3 concentration. The highest temperature composition has a d33 of 140 pmV-1 with a Tc = 542 °C, occupying previously unchartered territory on the classical d33-TC plot.

  16. The crystal structure of Kirkiite, Pb10Bi3As3S19

    DEFF Research Database (Denmark)

    Makovicky, Emil; Balic Zunic, Tonci; Karanovic, Ljiljana;

    2006-01-01

    The crystal structure of kirkiite has been solved using single-crystal data (MoKa X-ray diffraction, CCD area detector) to the conventional R-factor R1 = 0.069. It crystallizes in space group P21/m, with a 8.621(4), b 26.03(1), c 8.810(4) Å, ß 119.21(1)° and Z = 2. A crystal-structure determination....... The crystal structure of kirkiite can be described as (010) slabs of octahedra, three octahedra thick and related mutually by a refl ection plane situated in the intervening prismatic layer. In another interpretation, it is composed of slabs based on a transitional PbS-SnS archetype, with tightly bonded...

  17. Origin of epithermal Ag-Au-Cu-Pb-Zn mineralization in Guanajuato, Mexico

    Science.gov (United States)

    Mango, Helen; Arehart, Greg; Oreskes, Naomi; Zantop, Half

    2014-01-01

    The Guanajuato epithermal district is one of the largest silver producers in Mexico. Mineralization occurs along three main vein systems trending dominantly northwest-southeast: the central Veta Madre, the La Luz system to the northwest, and the Sierra system to the east. Mineralization consists dominantly of silver sulfides and sulfosalts, base metal sulfides (mostly chalcopyrite, galena, sphalerite, and pyrite), and electrum. There is a broad zonation of metal distribution, with up to 10 % Cu+Pb+Zn in the deeper mines along the northern and central portions of the Veta Madre. Ore occurs in banded veins and breccias and as stockworks, with gangue composed dominantly of quartz and calcite. Host rocks are Mesozoic sedimentary and intrusive igneous rocks and Tertiary volcanic rocks. Most fluid inclusion homogenization temperatures are between 200 and 300 °C, with salinities below 4 wt.% NaCl equivalent. Fluid temperature and salinity decreased with time, from 290 to 240 °C and from 2.5 to 1.1 wt.% NaCl equivalent. Relatively constant fluid inclusion liquid-to-vapor ratios and a trend of decreasing salinity with decreasing temperature and with increasing time suggest dilution of the hydrothermal solutions. However, evidence of boiling (such as quartz and calcite textures and the presence of adularia) is noted along the Veta Madre, particularly at higher elevations. Fluid inclusion and mineralogical evidence for boiling of metal-bearing solutions is found in gold-rich portions of the eastern Sierra system; this part of the system is interpreted as the least eroded part of the district. Oxygen, carbon, and sulfur isotope analysis of host rocks, ore, and gangue minerals and fluid inclusion contents indicate a hydrothermal fluid, with an initial magmatic component that mixed over time with infiltrating meteoric water and underwent exchange with host rocks. Mineral deposition was a result of decreasing activities of sulfur and oxygen, decreasing temperature, increasing p

  18. U-Pb (zircon) and geochemical constraints on the age, origin, and evolution of Paleozoic arc magmas in the Oyu Tolgoi porphyry Cu-Au district, southern Mongolia

    Science.gov (United States)

    Wainwright, A.J.; Tosdal, R.M.; Wooden, J.L.; Mazdab, F.K.; Friedman, R.M.

    2011-01-01

    Uranium-Pb (zircon) ages are linked with geochemical data for porphyry intrusions associated with giant porphyry Cu-Au systems at Oyu Tolgoi to place those rocks within the petrochemical framework of Devonian and Carboniferous rocks of southern Mongolia. In this part of the Gurvansayhan terrane within the Central Asian Orogenic Belt, the transition from Devonian tholeiitic marine rocks to unconformably overlying Carboniferous calc-alkaline subaerial to shallow marine volcanic rocks reflects volcanic arc thickening and maturation. Radiogenic Nd and Pb isotopic compositions (??Nd(t) range from +3.1 to +7.5 and 206Pb/204Pb values for feldspars range from 17.97 to 18.72), as well as low high-field strength element (HFSE) contents of most rocks (mafic rocks typically have rocks are dominantly medium- to high-K calc-alkaline and characterized by a decrease in Sr/Y ratios through time, with the Carboniferous rocks being more felsic than those of Devonian age. Porphyry Cu-Au related intrusions were emplaced in the Late Devonian during the transition from tholeiitic to calc-alkaline arc magmatism. Uranium-Pb (zircon) geochronology indicates that the Late Devonian pre- to syn-mineral quartz monzodiorite intrusions associated with the porphyry Cu-Au deposits are ~372Ma, whereas granodiorite intrusions that post-date major shortening and are associated with less well-developed porphyry Cu-Au mineralization are ~366Ma. Trace element geochemistry of zircons in the Late Devonian intrusions associated with the porphyry Cu-Au systems contain distinct Th/U and Yb/Gd ratios, as well as Hf and Y concentrations that reflect mixing of magma of distinct compositions. These characteristics are missing in the unmineralized Carboniferous intrusions. High Sr/Y and evidence for magma mixing in syn- to late-mineral intrusions distinguish the Late Devonian rocks associated with giant Cu-Au deposits from younger magmatic suites in the district. ?? 2010 Elsevier B.V.

  19. Enhanced production of low-mass electron-positron pairs in 40-AGeV Pb-Au collisions at the CERN SPS

    CERN Document Server

    Adamova, D; Appelshäuser, H; Belaga, V; Braun-Munzinger, P; Cherlin, A; Damjanovic, S; Dietel, T; Dietrich, L; Drees, A; Esumi, S I; Filimonov, K; Fomenko, K; Fraenkel, Zeev; Garabatos, C; Glässel, P; Hering, G; Holeczek, J; Kushpil, V; Lenkeit, B C; Maas, A; Marin, A; Milosevic, J; Milov, A; Miskowiec, D; Panebratsev, Yu A; Petchenova, O Yu; Petracek, V; Pfeiffer, A; Rak, J; Ravinovich, I; Rehak, P; Richter, M; Sako, H; Schmitz, W; Sedykh, S; Seipp, W; Sharma, A; Shimansky, S S; Slivova, J; Specht, H J; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Wessels, J P; Wienold, T; Windelband, B; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V I

    2003-01-01

    We report on first measurements of low-mass electron pairs in Pb-Au collisions at the lower SPS beam energy of 40 AGeV. The pair yield integrated over the range of invariant masses 0.2 e+ e- annihilation with a modified rho-propagator. They may be linked to chiral symmetry restoration and support the notion that the in-medium modifications of the rho are more driven by baryon density than by temperature.

  20. Enhanced production of low-mass electron-positron pairs in 40-AGeV Pb-Au collisions at the CERN SPS.

    Science.gov (United States)

    Adamová, D; Agakichiev, G; Appelshäuser, H; Belaga, V; Braun-Munzinger, P; Cherlin, A; Damjanović, S; Dietel, T; Dietrich, L; Drees, A; Esumi, S I; Filimonov, K; Fomenko, K; Fraenkel, Z; Garabatos, C; Glässel, P; Hering, G; Holeczek, J; Kushpil, V; Lenkeit, B; Maas, A; Marín, A; Milosević, J; Milov, A; Miśkowiec, D; Panebrattsev, Yu; Petchenova, O; Petrácek, V; Pfeiffer, A; Rak, J; Ravinovich, I; Rehak, P; Richter, M; Sako, H; Schmitz, W; Sedykh, S; Seipp, W; Sharma, A; Shimansky, S; Slívová, J; Specht, H J; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, I; Wessels, J P; Wienold, T; Windelband, B; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V

    2003-07-25

    We report on first measurements of low-mass electron-positron pairs in Pb-Au collisions at the CERN SPS beam energy of 40 AGeV. The observed pair yield integrated over the range of invariant masses 0.2e(+)e(-) annihilation with a modified rho propagator. They may be linked to chiral symmetry restoration and support the notion that the in-medium modifications of the rho are more driven by baryon density than by temperature.

  1. 119Sn-Mössbauer spectroscopic study of the single phase of Bi(Pb) sbnd Sr sbnd Ca sbnd Cu(Sn) sbnd O

    Science.gov (United States)

    Matsumoto, Y.; Nishida, T.; Katada, M.; Deshimaru, Y.; Miura, N.; Yamazoe, N.

    Tin-doped samples of the high- Tc (2223) phase of Bi sbnd Pb sbnd Sr sbnd Ca sbnd Cu sbnd O superconductor have been prepared by a conventional sintering method. Sintering conditions were carefully selected to obtain the single high- Tc phase. 119Sn-Mössbauer spectra have been measured in the temperature range from 4.2 to 300 K. The temperature dependence of the recoilless fraction ( f) is well understood by the temperature dependence of the normal phonon.

  2. Application of the annexation principle to the study of thermodynamic properties of ternary metallic melts In-Pb-Ag and In-Bi-Sb

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the phase diagrams, measured activities and the annexation principle, the calculating models of mass action concentrations for In-Pb-Ag and In-Bi-Sb ternary metallic melts have been formulated. The results of calculation both agree with practice, and obey the law of mass action, showing that the models formulated can reflect the structural reality of the corresponding melts and the annexation principle is applicable to the them.

  3. Friction and wear behavior of the superconducting compound oxide of Ag/Bi_(1. 6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x)%超导Ag/Bi_(1.6)Pb_(0.4)Sr_2Ca_2Cu_3O_(10-x)复合氧化物摩擦磨损性能

    Institute of Scientific and Technical Information of China (English)

    彭义; 李长生; 董丽荣; 丁巧党; 王昊璐

    2009-01-01

    The superconducting Bi_(1.6)Pb_(0.4)Sr_2Ca_2Cu_3O_(10-x) samples were prepared by the solid-state synthesismethod. The tribological properties were measured on the friction and wear tester from ambient temperature toliquid nitrogen temperature. The results indicate that the friction coefficient of Bi_(1.6)Pb_(0.4)Srz_2Ca_2Cu_30_(10-x) againststainless steel is about 0.35 at the ambient temperature and decreases abruptly to half of the normal state value whenthe temperature is below the superconducting transition temperature of Bi_(1.6)Pb_(0. 4_Srz_2Ca_2Cu_30_(10-x). Themeasurements prove directly the effect of electronic excitation on friction. Moreover, the Ag/Bi_(1.6) Pb_(0.4)Sr_2Ca_2Cu_3O_(10-x) composite samples were prepared by sintering Bi_(1.6)Pb_(0.4)Sr_2Ca_2Cu_3O_(10-x) with Ag at different mass fractions to improve the tribological properties of Bi_(1.6)Pb_(0.4)Sr_2Ca_2Cu_3O_(10-x) at room temperature. The experimental results show that the friction coefficient of 10 Wt%Ag/Bi_(1. 6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x) is about 0. 2~O. 3 and the wear rate is 4. 57×10~(-4)mm~3·(N·m)~(-1), and the superconductivity of 10 Wt% Ag/Bi_(1. 6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x) is not degenerated.%为适应20℃~-200℃温度的适用范围, 采用固相法制备了Bi_(1.6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x)超导材料, 用摩擦磨损试验机测试了Bi_(1.6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x)从液氮温度至室温的摩擦学性能. 结果表明: 在室温20℃下, Bi_(1. 6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x)与对偶件轴承钢盘对摩时, 摩擦系数约为0. 35, 当温度降到超导转变温度以下时(液氮温度-170℃)摩擦系数大幅度降低, Bi_(1. 6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x)超导态摩擦系数为正常态值的一半, 实验证明了电子激励对摩擦能量耗散的作用. 为改善室温下Bi_(1. 6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x)摩擦学性能, 掺杂不同质量分数Ag作为润滑组元, 制备了Ag/Bi_(1. 6) Pb_(0. 4)Sr_2Ca_2Cu_3O_(10-x)

  4. Study on core radius minimization for long life Pb-Bi cooled CANDLE burnup scheme based fast reactor

    Science.gov (United States)

    Afifah, Maryam; Miura, Ryosuke; Su'ud, Zaki; Takaki, Naoyuki; Sekimoto, H.

    2015-09-01

    Fast Breeder Reactor had been interested to be developed over the world because it inexhaustible source energy, one of those is CANDLE reactor which is have strategy in burn-up scheme, need not control roads for control burn-up, have a constant core characteristics during energy production and don't need fuel shuffling. The calculation was made by basic reactor analysis which use Sodium coolant geometry core parameter as a reference core to study on minimum core reactor radius of CANDLE for long life Pb-Bi cooled, also want to perform pure coolant effect comparison between LBE and sodium in a same geometry design. The result show that the minimum core radius of Lead Bismuth cooled CANDLE is 100 cm and 500 MWth thermal output. Lead-Bismuth coolant for CANDLE reactor enable to reduce much reactor size and have a better void coefficient than Sodium cooled as the most coolant for FBR, then we will have a good point in safety analysis.

  5. CONTRIBUTIONS TO THE STUDY OF HEAVY METALS DISTRIBUTION (Zn, Pb, Cd, Bi, Cu IN SOME SOILS FROM GIURGEU MOUNTAINS

    Directory of Open Access Journals (Sweden)

    D. Bulgariu

    2005-10-01

    Full Text Available In this paper are presented the results of mineralogical and geochemical studies, realized for few soils from Giurgeu Mountains, which have as main purpose the distribution and mobility interpretation of minor elements (Cd, Cu, Pb, Zn, Bi in studied soil samples. The determination of fixed fractions and mobile fractions weight, at total contents of studied elements, and relative association of these elements with main mineral and organic components of soil samples, was realized on the basis of results obtained by sequential solid/ liquid extraction. The same, we try to use the correlation establish between metallic ions contents, as indicators of mineral paragenesis (the genetic type and formation conditions. The obtained results are agree with the results of similar studies from literature and they, underline of some interesting aspects about of distribution and migration of heavy metals in soils: (1 exist of some selectivity in heavy metals distribution in mineral components from soils, correlated with reciprocals geochemical affinities between speciation forms of metals and mineral components, in a given pedogeochemical context; (2 the heavy metals distribution between solid phases and soil solution are realized in competitive regime, and the inter-phases equilibrium evolution are thermodynamic and kinetics controlled by the solid/ liquid interfaces processes; (3 the fast elementary processes and local fluctuations of physic-chemical parameters are the main factors which controlled the inter-phases transfer ratio and the evolution direction of equilibriums of heavy metals distribution.

  6. Study Neutronic of Small Pb-Bi Cooled Non-Refuelling Nuclear Power Plant Reactor (SPINNOR) with Hexagonal Geometry Calculation

    Science.gov (United States)

    Nur Krisna, Dwita; Su'ud, Zaki

    2017-01-01

    Nuclear reactor technology is growing rapidly, especially in developing Nuclear Power Plant (NPP). The utilization of nuclear energy in power generation systems has been progressing phase of the first generation to the fourth generation. This final project paper discusses the analysis neutronic one-cooled fast reactor type Pb-Bi, which is capable of operating up to 20 years without refueling. This reactor uses Thorium Uranium Nitride as fuel and operating on power range 100-500MWtNPPs. The method of calculation used a computer simulation program utilizing the SRAC. SPINNOR reactor is designed with the geometry of hexagonal shaped terrace that radially divided into three regions, namely the outermost regions with highest percentage of fuel, the middle regions with medium percentage of fuel, and most in the area with the lowest percentage. SPINNOR fast reactor operated for 20 years with variations in the percentage of Uranium-233 by 7%, 7.75%, and 8.5%. The neutronic calculation and analysis show that the design can be optimized in a fast reactor for thermal power output SPINNOR 300MWt with a fuel fraction 60% and variations of Uranium-233 enrichment of 7%-8.5%.

  7. Doping dependent metal to insulator transition in the (Bi,Pb)-2212 system: The evolution of structural and electronic properties with europium substitution

    Institute of Scientific and Technical Information of China (English)

    Shabna Razia; Sarun Pallian Murikoli; Vinu Surendran; Syamaprasad Upendrant

    2009-01-01

    The present work investigates the effect of europium substitution on the (Bi,Pb)-2212 system in the concentration range 0.5≤χ≤ 1.0. Phase analysis and lattice parameter calculations on the powder diffraction data and the elemental analysis of EDX show that the Eu atoms are successfully substituted into the (Bi,Pb)-2212 system. Resistivity measurements (64-300 K) reveal that the system exhibits superconductivity at χ≤ 0.5 and semiconductivity at χ>0.5.With the complete suppression of superconductivity which is known to be a quasi-two dimensional phenomenon in these materials,a metal to insulator transition takes place at χ= 0.6 and the predominant conduction mechanism is found to be variable range hopping between localized states,resulting in macroscopic semiconducting behaviour. The results of electrical and structural properties of the doped (Bi,Pb)-2212 compounds suggest that the decrease of charge carrier concentration and the induced structural disorder are the more effective and dominant mechanisms in the origin of the metal to insulator transition and suppression of superconductivity due to Eu substitution at its Sr site.

  8. Effect of Ag2O addition on the intergranular properties of the superconducting Bi-(Pb)-Sr-Ca-Cu-O system

    Science.gov (United States)

    Karaca, I.; Çelebi, S.; Varilci, A.; Malik, A. I.

    2003-01-01

    The effect of Ag2O addition on the Bi-(Pb)-Sr-Ca-Cu-O system has been investigated in terms of ac susceptibility, phase evolution, critical current density and critical temperature. It was found that as the amount of Ag2O addition increases, the intergranular critical current density decreases in our samples (Bi1.84Pb0.34Sr1.91Ca2.03Cu3.06O10) fabricated by ammonium nitrate technique. The analysis for comparison is based on the suppression degree of the diamagnetic behaviour with respect to fields, rapid or slow shift of the summit in chi'(T) to lower temperature with increasing field amplitude and the sharpness of the transition of chi'(T) for intergranular component for the same field amplitude. We also qualitatively discuss experimental results in the framework of the critical state model. The room temperature XRD diagram indicates the presence of large amount of high-Tc (2223) phase. The percentage of Bi-2223 phase in the phase mixture was estimated from the intensities of high-Tc (2223) and low-Tc (2212) phase peaks as 78% for the pure BSCCO sample. Among the Ag2O-added BSCCO samples studied, the one in which 5 wt%Ag2O was added shows the highest rate of Bi-2223 formation as 92%. The SEM analysis reveals some morphological changes induced by silver addition.

  9. Effects of K doping on structural and superconducting properties of Bi{sub 1.5}Pb{sub 0.5}Sr{sub 1.8}CaCu{sub 2}O{sub 8+δ} compounds

    Energy Technology Data Exchange (ETDEWEB)

    Belala, K; Mosbah, M. F. [Material Sciences and Applications Research Unit, Physics Department, Constantine 1 University, B.P. 325 Route d' Ain El Bey, 25017 Constantine (Algeria)

    2013-12-16

    Two kinds of potassium doped Bi(Pb)2212 samples are used to investigate the effect of doping the Bi(Pb)2212 ((Bi,Pb){sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}) phase by potassium (K): In the first one K is substituted on the Sr site; In the second one K is added. Using the solid state method reaction samples of Bi{sub 1.5}Pb{sub 0.5}(Sr{sub 1.8−x}K{sub x})CaCu{sub 2}O{sub 8+d} and Bi{sub 1.5}Pb{sub 0.5}Sr{sub 1.8}CaCu{sub 2}O{sub 8+d}K{sub x} (0 ≤ x≤ 0.05) have been prepared from powders of carbonates and primary oxides having purity over 99%. The samples have been characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and resistivity versus temperature measurements. Results show how the kind and the rate of doping by potassium affects the structural and transport properties of Bi(Pb)2212 phase.

  10. Intermetallic compounds of the heaviest elements and their homologs: The electronic structure and bonding of MM', where M =Ge, Sn, Pb, and element 114, and M'=Ni, Pd, Pt, Cu, Ag, Au, Sn, Pb, and element 114

    Science.gov (United States)

    Pershina, V.; Anton, J.; Fricke, B.

    2007-10-01

    Fully relativistic (four-component) density-functional theory calculations were performed for intermetallic dimers MM', where M =Ge, Sn, Pb, and element 114, and M'=group 10 elements (Ni, Pd, and Pt) and group 11 elements (Cu, Ag, and Au). PbM and 114M, where M are group 14 elements, were also considered. The results have shown that trends in spectroscopic properties—atomization energies De, vibrational frequencies ωe, and bond lengths Re, as a function of M', are similar for compounds of Ge, Sn, Pb, and element 114, except for De of PbNi and 114Ni. They were shown to be determined by trends in the energies and space distribution of the valence ns(M ') atomic orbitals (AOs). According to the results, element 114 should form the weakest bonding with Ni and Ag, while the strongest with Pt due to the largest involvement of the 5d(Pt) AOs. In turn, trends in the spectroscopic properties of MM' as a function of M were shown to be determined by the behavior of the np1/2(M ) AOs. Overall, De of the element 114 dimers are about 1eV smaller and Re are about 0.2a.u. larger than those of the corresponding Pb compounds. Such a decrease in bonding of the element 114 dimers is caused by the large SO splitting of the 7p orbitals and a decreasing contribution of the relativistically stabilized 7p1/2(114) AO. On the basis of the calculated De for the dimers, adsorption enthalpies of element 114 on the corresponding metal surfaces were estimated: They were shown to be about 100-150kJ/mol smaller than those of Pb.

  11. Point Defects in Pb-, Bi-, and In-Doped CdZnTe Detectors:Deep-Level Transient Spectroscopy (DLTS) Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov A.; GUL, R.; KEETER, K.; RODRIGUEZ, R.; BOLOTNIKOV, A.E.; HOSSAIN, A.; CAMARDA, G.S.; KIM, K.H.; YANG, Y.; CUI, Y.; CARCELEN, V.; FRANC, J.; LI, Z.; JAMES, R.B.

    2012-02-29

    We studied, by current deep-level transient spectroscopy (I-DLTS), point defects induced in CdZnTe detectors by three dopants: Pb, Bi, and In. Pb-doped CdZnTe detectors have a new acceptor trap at around 0.48 eV. The absence of a V{sub Cd} trap suggests that all Cd vacancies are compensated by Pb interstitials after they form a deep-acceptor complex [[Pb{sub Cd}]{sup +}-V{sub Cd}{sup 2-}]{sup -}. Bi-doped CdZnTe detectors had two distinct traps: a shallow trap at around 36 meV and a deep donor trap at around 0.82 eV. In detectors doped with In, we noted three well-known traps: two acceptor levels at around 0.18 eV (A-centers) and 0.31 eV (V{sub Cd}), and a deep trap at around 1.1 eV.

  12. On the analogy between photoluminescence and carrier-type reversal in Bi- and Pb-doped glasses

    National Research Council Canada - National Science Library

    Hughes, Mark A; Gwilliam, Russell M; Homewood, Kevin; Gholipour, Behrad; Hewak, Daniel W; Lee, Tae-Hoon; Elliott, Stephen R; Suzuki, Takenobu; Ohishi, Yasutake; Kohoutek, Tomas; Curry, Richard J

    2013-01-01

    .... Bi-related PL bands have been observed in glasses with very similar compositions to those in which carrier-type reversal has been observed, indicating that these phenomena are related to the same Bi...

  13. Activity of indium in molten In-Pb-Ag and In-Bi-Sb alloys measured by EMF method using zironia electrolyte; Jirukonia kotai denkaishitsu denchiho ni yoru yoyu In-Pb-Ag kei oyobi In-Bi-Sb kei gokin no injiumu no karyo sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Kameda, K.; Yamaguchi, K.; Kon, T. [Iwate Univ., Iwate (Japan). Faculty of Engineering

    1997-05-20

    In, Ag, Bi, Sb and so forth are slight amount of coexisted elements in non iron metal such as Cu, Pb, Zn and so forth. It has been used as a structure element of electronic material or functional material of superconductors, surface terminal element, transparent electrode and so forth. Further, in future, development regarding its use in optical communication, photovoltaic power generation and so forth is expected. Ag, Bi when combined with In, forming low melting point alloy, can be used as a contact material or dental alloy. Demand of Sb as a flame auxiliary retarder has been increased. In this report, as for molten In-Pb-Ag, In-Pb-Ag type alloys which are not reported so far, cell using zirconia solid electrolyte was prepared and electromotive force was measured. From the obtained value of electromotive force, activity of indium in the whole composition region of In-Pb-Ag type at 1100K and 1200K, and In-Bi-Sb alloy at 1000K and 1100K was measured directly, and isoactivity curve of three elemental alloy was determined. 7 refs., 6 figs., 2 tabs.

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

    Science.gov (United States)

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

    2015-07-21

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

  15. Unusual transformation from strong negative to positive thermal expansion in PbTiO3-BiFeO3 perovskite.

    Science.gov (United States)

    Chen, Jun; Fan, Longlong; Ren, Yang; Pan, Zhao; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

    2013-03-15

    Tetragonal PbTiO(3)-BiFeO(3) exhibits a strong negative thermal expansion in the PbTiO(3)-based ferroelectrics that consist of one branch in the family of negative thermal expansion materials. Its strong negative thermal expansion is much weakened, and then unusually transforms into positive thermal expansion as the particle size is slightly reduced. This transformation is a new phenomenon in the negative termal expansion materials. The detailed structure, temperature dependence of unit cell volume, and lattice dynamics of PbTiO(3)-BiFeO(3) samples were studied by means of high-energy synchrotron powder diffraction and Raman spectroscopy. Such unusual transformation from strong negative to positive thermal expansion is highly associated with ferroelectricity weakening. An interesting zero thermal expansion is achieved in a wide temperature range (30-500 °C) by adjusting particle size due to the negative-to-positive transformation character. The present study provides a useful method to control the negative thermal expansion not only for ferroelectrics but also for those functional materials such as magnetics and superconductors.

  16. Thermoelectric properties of p-type (Bi0.15Sb0.85)2Te3-PbTe graded thermoelectric materials with different barriers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The p-type (Bi0.15Sb0.85)2Te3 and PbTe are typical thermoelectric materials used for low and middle temperature range and functional graded materials (FGM) is an inevitable way to widen the working temperature range. Here two segments graded thermoelectric materials (GTM) consisting of (Bi0.15Sb0.85)2Te3, PbTe and different barriers were fabricated by the common hot pressure method. Metals Fe, Mg and Ni were used as barriers between the two segments. The diffusion of different barriers between the barriers and bases were analyzed by electron microprobe analysis (EMA). The phase and crystal structures were determined by X-ray diffraction analysis (XRD). The thermoelectric properties were measured at 303 K along the direction parallel to the pressing direction.The results show that the compositional diffusion occurs when there is no barrier at the interface of the two segments, and the diffusion of Pb is most obvious; as the barrier material, the diffusion of metals Fe, Mg and Ni between different bases is not very obvious,and the thermoelectric properties of GTM is much better than that of the original segment.

  17. Study of nanocrystalline BiMnO3-PbTiO3: synthesis, structural elucidation, and magnetic characterization of the whole solid solution.

    Science.gov (United States)

    Hungría, Teresa; Correas, Covadonga; Houdellier, Florent; Peña, Octavio; Vila, Eladio; Castro, Alicia

    2012-07-16

    In the last ten years, the study and the search for new multiferroic materials have been a major challenge due to their potential applications in electronic technology. In this way, bismuth-containing perovskites (BiMO(3)), and particularly those in which the metal M position is occupied by a magnetically active cation, have been extensively investigated as possible multiferroic materials. From the point of view of synthesis, only a few of the possible bismuth-containing perovskites can be prepared by conventional methods but at high pressures. Herein, the preparation of one of these potential multiferroic systems, the solid solution xBiMnO(3)-(1-x)PbTiO(3) by mechanosynthesis is reported. Note that this synthetic method allows the oxides with high x values, and more particularly the BiMnO(3) phase, to be obtained as nanocrystalline phases, in a single step and at room temperature without the application of external pressure. These results confirm that, in the case of Bi perovskites, mechanosynthesis is a good alternative to high-pressure synthesis. These materials have been studied from the point of view of their structural characteristics by precession electron diffraction and magnetic property measurements.

  18. Stability Limits of the Liquid Phase in the Layered Mo/Pb/Mo, Mo/Bi/Mo and Mo/In/Mo Film Systems

    Directory of Open Access Journals (Sweden)

    S.I. Petrushenko

    2016-12-01

    Full Text Available The results of the study of supercooling of the fusible metals films between the continuous layers of molybdenum during the crystallization are given. Due to an original in situ technique based on the changes of resistance of samples during heating and cooling directly in the vacuum chamber the values of supercooling in Mo/Pb/Mo, Mo/Bi/Mo, Mo/In/Mo films are determined and the influence of the morphological structure of the bismuth inclusions on the temperature and nature of its supercooled melt crystallization has been found. The substrate temperature change during the condensation of samples, accompanied by a corresponding change in their microstructure, allows realizing both avalanche and diffuse crystallization and changing of supercooling value in the range of 60 to 180 K in Mo/Bi/Mo films.

  19. Excitation functions of $^{nat}$Pb(d,x)$^{206,205,204,203,202}$Bi, $^{203cum,202m,201cum}$Pb and $^{202cum,201cum}$Tl reactions up to 50 MeV

    CERN Document Server

    Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2014-01-01

    Cross-sections of deuteron induced nuclear reactions on lead were measured up to 50 MeV using the standard stacked foil irradiation technique and high resolution $\\gamma$-ray spectrometry. Experimental cross-sections and derived integral yields are presented for the $^{nat}$Pb(d,x)$^{206,205,204,203,202}$Bi, $^{203cum,202m,201cum}$Pb and $^{202cum,201cum}$Tl reactions. The experimental data were compared with the results from literature and with the data in the TENDL-2013 library (obtained with TALYS code). The cross-section data were analyzed also with the theoretical results calculated by using the ALICE-IPPPE-D and EMPIRE-D codes.

  20. Long range absorption in the scattering of {sup 6}He on {sup 208}Pb and {sup 197}Au at 27 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kakuee, O.R. [Van De Graaf Laboratory, Nuclear Research Centre, AEOI, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of)]|[Departamento de Fisica Atomica, Molecular y Nuclear, Apartado 1065, Universidad de Sevilla, E-41080 Sevilla (Spain); Alvarez, M.A.G. [Departamento de Fisica Atomica, Molecular y Nuclear, Apartado 1065, Universidad de Sevilla, E-41080 Sevilla (Spain); Andres, M.V. [Departamento de Fisica Atomica, Molecular y Nuclear, Apartado 1065, Universidad de Sevilla, E-41080 Sevilla (Spain); Cherubini, S. [Department de Physique Nucleaire, Universite Catholique, Louvain-la-Neuve (Belgium)]|[Institut fuer Experimentalphysik III, Ruhr-Universitaet Bochum (Germany); Davinson, T.; Di Pietro, A.; Laird, A.M.; Shotter, A.C.; Smith, W.B.; Woods, P.J. [Department of Physics and Astronomy, Edinburgh University, EH9 3JZ (United Kingdom); Galster, W. [Department de Physique Nucleaire, Universite Catholique, Louvain-la-Neuve (Belgium); Gomez-Camacho, J. [Departamento de Fisica Atomica, Molecular y Nuclear, Apartado 1065, Universidad de Sevilla, E-41080 Sevilla (Spain)]. E-mail: gomez@us.es; Lamehi-Rachti, M. [Van De Graaf Laboratory, Nuclear Research Centre, AEOI, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of); Martel, I. [Departamento de Fisica Aplicada, Universidad de Huelva, E-21819 Huelva (Spain); Moro, A.M. [Departamento de Fisica Atomica, Molecular y Nuclear, Apartado 1065, Universidad de Sevilla, E-41080 Sevilla (Spain); Rahighi, J. [Van De Graaf Laboratory, Nuclear Research Centre, AEOI, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of)]|[Department of Physics and Astronomy, Edinburgh University, EH9 3JZ (United Kingdom); Sanchez-Benitez, A.M. [Departamento de Fisica Aplicada, Universidad de Huelva, E-21819 Huelva (Spain); Vervier, J. [Department de Physique Nucleaire, Universite Catholique, Louvain-la-Neuve (Belgium)

    2006-02-06

    Quasi-elastic scattering of {sup 6}He at E{sub lab}=27 MeV from {sup 197}Au has been measured in the angular range of 6{sup o}-72{sup o} in the laboratory system employing LEDA and LAMP detection systems. These data, along previously analysed data of {sup 6}He+{sup 208}Pb at the same energy, are analysed using optical model calculations. The role of Coulomb dipole polarizability has been investigated. Large imaginary diffuseness parameters are required to fit the data. This result is an evidence for long range absorption mechanisms in {sup 6}He induced reactions.

  1. Preparation of (Bi,Pb)2Sr2Ca2Cu3Ox precursor powders by a modified polyethylene glycol based sol-gel process

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Andersen, N.H.

    2002-01-01

    A modified sol-gel process based on polyethylene glycol has been developed for preparing (Bi,Pb)(2)Sr2Ca2Cu3Ox precursor powders in view of Ag-sheeted tape manufacture. A careful control of the pH and concentration temperature yields an amorphous gel, which can be converted to a fine and extremely...... reactive powder. The reactions taking place during the process were studied. Various calcination conditions were used in order to obtain precursor powders having different characteristics (grain size distribution. phase assembly). The influence of precursor preparation parameters on the formation...

  2. Superconducting Bi(1.5)Pb(0.5)Sr2Ca2Cu3O(x) ceramics by rapid melt quenching and glass crystallization

    Science.gov (United States)

    Bansal, Narottam P.

    1990-01-01

    The preparation of superconducting Bi(1.5)Pb(0.5)Sr2Ca2Cu3O(x) in the glassy state is described, and the results of a study of its crystallization kinetics are presented. The annealing parameters for transforming the glass into a superconductor containing a large fraction of the high-Tc phase were determined. It was found that prolonged annealing (longer than 10 days) in air at 840 C, followed by slow cooling, results in the Tc of 107.2 K and a sharp transition of 2 K.

  3. Thickness-dependent retention behaviors and ferroelectric properties of BiFeO3 thin films on BaPbO3 electrodes

    Science.gov (United States)

    Lee, Chia-Ching; Wu, Jenn-Ming

    2007-09-01

    BiFeO3 (BFO) thin films produced with varied film thicknesses ranging from 100to230nm were fabricated on BaPbO3(BPO )/Pt/Ti/SiOx/Si substrates by rf-magnetron sputtering. Saturated polarization-electrical field hysteresis loops, polarization response by pulse measurement, and retention properties were obtained for BFO films with various thicknesses on BPO. The retention behaviors of BFO demonstrate logarithmic time dependence and stretched exponential law. When the thicknesses of BFO films increase, the contribution of logarithmic time dependence to retention, the stretched exponential law becomes dominant. BFO films with thinner thickness exhibit better retention properties but possess smaller remnant polarization.

  4. Effect of CuF2 on the Synthesis and Superconducting Properties of (Bi,Pb)2Sr2Ca2Cu3O10 Bulk Ceramic Samples

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Andersen, Niels Hessel

    2013-01-01

    Bulk polycrystalline samples with Bi1.72Pb0.34Sr1.87Ca1.91Cu3.13O9.83−x F x (0.00≤x≤0.51) were prepared by a solid-state route using CuF2 as a fluorine source. CuF2 was introduced in the precursor powders either by direct mixing with the other starting reagents or by addition to precalcined precu...

  5. Structural and dielectric properties of erbium doped BiFeO{sub 3}−PbTiO{sub 3} solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vandana,, E-mail: anupinders@gmail.com; Singh, Anupinder, E-mail: anupinders@gmail.com; Singh, Lakhwant, E-mail: anupinders@gmail.com; Kaur, Anumeet, E-mail: anupinders@gmail.com [Multifunctional Materials Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar-143005 (India); Dahyia, Sajjan [Department of Physics, Maharshi Dayanand University, Rohtak-124001 (India); Chatterjee, Ratnamala [Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016 (India)

    2014-04-24

    Single phase Er substituted at A-site BiFeO{sub 3}−PbTiO{sub 3} solid solutions were synthesized using solid state reaction route. The calcinations at different temperature reveals that the single and pure tetragonal phase formation has been accomplished at 1000°C. The SEM micrographs did not show any distinguishable change in grain size. The dielectric studies established that the dielectric constant decreases and ferroelectric T{sub c} increases with increase in Er.

  6. The crystal structure of (001) twinned xilingolite, Pb3Bi2S6, from Mittal-Hohtenn, Valais, Switzerland

    DEFF Research Database (Denmark)

    Berlepsch, Peter; Armbruster, Thomas; Makovicky, Emil

    2002-01-01

    geology, xilingolite, crystal structure, twinning, lillianite homologue, electron-microprobe analyses, cannizzarite, Bi-containing galena, Mittal-Hohtenn, Valais, Switzerland......geology, xilingolite, crystal structure, twinning, lillianite homologue, electron-microprobe analyses, cannizzarite, Bi-containing galena, Mittal-Hohtenn, Valais, Switzerland...

  7. Assay methods for U-238, Th-232, and Pb-210 in lead and calibration of Bi-210 bremsstrahlung emission from lead

    CERN Document Server

    Orrell, John L; Arnquist, Isaac J; Eggemeyer, Tere A; Glasgow, Brian D; Hoppe, Eric W; Keillor, Martin E; Morley, Shannon M; Myers, Allan W; Overman, Cory T; Shaff, Sarah M; Thommasson, Kimbrelle S

    2015-01-01

    Assay methods for measuring 238U, 232Th, and 210Pb concentrations in refined lead are presented. The 238U and 232Th concentrations are determined using isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) after anion exchange column separation of dissolved lead samples. The 210Pb concentration is inferred through {\\alpha}-spectroscopy of a daughter isotope, 210Po, after chemical precipitation separation on dissolved lead samples. Subsequent to the 210Po {\\alpha}-spectroscopy assay, a method for evaluating 210Pb concentrations in solid lead samples was developed via measurement of bremsstrahlung radiation from \\b{eta}-decay of a daughter isotope, 210Bi, by employing a 14-crystal array of high purity germanium (HPGe) detectors. Ten sources of refined lead were assayed. The 238U concentrations were <34 microBq/kg and the 232Th concentrations ranged <0.6-15 microBq/kg, as determined by the ICP-MS assay method. The 210Pb concentrations ranged from ~0.1-75 Bq/kg, as inferred by the 210Po ...

  8. Extended x-ray absorption fine structure study of incorporation of Bi and Pb atoms into the crystal structure of Ba{sub 4.5}Nd{sub 9}Ti{sub 18}O{sub 54}

    Energy Technology Data Exchange (ETDEWEB)

    Valant, M.; Arcon, I.; Suvorov, D.; Kodre, A. [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, University of Ljubljana (Slovenia); Negas, T. [Trans-Tech Inc., Adamstown, Maryland 21702 (United States); Frahm, R. [Hambruger Synchrotronstrahlungslabor at Deutsches Elektronen Synchrotron DESY, Hamburg (Germany)

    1997-03-01

    In extended x-ray aborption fine structure (EXAFS) study of local environment of Bi{sup 3+} and Pb{sup 2+} ions incorporated in Ba{sub 4.5}Nd{sub 9}Ti{sub 18}O{sub 54} actual sites of Bi- and Pb-incorporated are determined. Evidences are given that dopant ions are not distributed randomly on all theoretically possible sites: Bi{sup 3+} selectively enters one out of three posible channels, corresponding to the sites x=0.9484, y=0.2500, z=0.2939, and/or x=0.0455, y=0.2500, z=0.6928 previously occupied by Nd{sup 3+}, while Pb{sup 2+} selectively enters site x=0.4940, y=0.2500, z=0.4993 previously shared by Ba{sup 2+} and Nd{sup 3+}. {copyright} {ital 1997 Materials Research Society.}

  9. Infrared Study of Er3+/Yb3+ Co-Doped GeO2-PbO-Bi2O3 Glass

    Directory of Open Access Journals (Sweden)

    Mohamed K. Halimah

    2012-07-01

    Full Text Available Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO2-PbO-Bi2O3 glass host doped with Er3+/Yb3+ ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR results showed that PbO and Bi2O3 participate with PbO4 tetragonal pyramids and strongly distort BiO6 octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.

  10. Mesoscopic-scale structure and dynamics near the morphotropic phase boundary of (1 -x ) PbTiO3-x BiScO3

    Science.gov (United States)

    Datta, K.; Richter, A.; Göbbels, M.; Neder, R. B.; Mihailova, B.

    2015-07-01

    A range of compelling information on the local structure and dynamics of the ferroelectric perovskite-type (ABO3) system (1 -x ) PbTiO3-x BiScO3 has been revealed through analyzing room-temperature x-ray pair distribution functions and temperature-dependent Raman scattering data for compositions ranging across the morphotropic phase boundary (MPB). Raman scattering data have provided exclusive evidence for distinct dynamical responses from the A-site Pb/Bi and the B-site Ti/Sc cations as a function of composition and temperature. Both pair distribution function and Raman scattering analyses indicate improved coherence between the A-site and B-site off-center displacements for x above the MPB composition. The distinguishable dynamical features were spotted between two sets of compositional range from which x =0.34 could be assigned as a critical composition of "local" MPB: the composition at which the pathway of mesoscopic-scale temperature-driven coupling and transformation processes changes. This differs from the previous reports based on the analysis of the average structure, suggesting the response function of a system may not necessarily follow the evolution of the average structure from which however the MPB has so far been ascribed for a particular system. The individual features of the cations revealed here will further help in understanding the structure-property correlations for similar ferroelectric solid solutions.

  11. Superconducting and mechanical properties of the bulk Bi(pb)SCCO system prepared via solid state and ammonium nitrate precipitation methods

    Energy Technology Data Exchange (ETDEWEB)

    Safran, S., E-mail: safran@science.ankara.edu.tr [Ankara University, Faculty of Science, Department of Physics, Tandoğan, Ankara 06100 (Turkey); Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Kılıçarslan, E.; Ozturk, H. [Ankara University, Faculty of Science, Department of Physics, Tandoğan, Ankara 06100 (Turkey); Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Alp, M. [Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Akdogan, M. [Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Abant İzzet Baysal University, Department of Physics, Bolu (Turkey); Asikuzun, E.; Ozturk, O. [Kastamonu University, Department of Physics, Kastamonu (Turkey); Kastamonu University, Research and Application Center, Kastamonu (Turkey); Kılıç, A. [Ankara University, Faculty of Science, Department of Physics, Tandoğan, Ankara 06100 (Turkey); Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey)

    2015-09-01

    We have investigated the effect of preparation method on superconducting and mechanical properties of Bi(Pb)-2223 bulk samples using Bi{sub 1.85}Pb{sub 0.35}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10±y} stoichiometry. Solid-state reaction and ammonium nitrate precipitation methods have been used for fabrication of the bulk samples. In addition, the effect of annealing time on BSCCO samples have been studied. Structural, electrical, magnetic and microhardness analyses of samples are performed by the X-ray powder diffraction (XRD), the Scanning Electron Microscopy (SEM), DC resistivity, AC susceptibility and Vickers microhardness test. The critical transition temperature, phase purity, surface morphology and crystallinity of the prepared bulk samples are compared with each other. Elasticity (E), brittleness (B{sub i}), fracture toughness (K{sub IC}) and yield strength (Y) values are also determined according to annealing time, applied load and production parameters of materials.

  12. Incommensurate Spin Correlations Induced by Magnetic Fe ions Substituted into Overdoped Bi1.75Pb0.35Sr1.90CuO6+z

    Energy Technology Data Exchange (ETDEWEB)

    Hiraka, H.; Tranquada, J.; Hayashi, Y.; Wakimoto, S.; Takeda, M.; Kakurai, K.; Adachi, T.; Koike, Y.; Yamada, I.; Miyazaki, M.; Hiraishi, M.; Takeshita, S.; Kohda, A.; Kadono, R.; Yamada, K.

    2010-04-01

    Spin correlations in the overdoped region of Bi{sub 1.75}Pb{sub 0.35}Sr{sub 1.90}CuO{sub 6+z} have been explored with Fe-doped single crystals characterized by neutron scattering, muon-spin-rotation spectroscopy, and magnetic-susceptibility measurements. Static incommensurate spin correlations induced by the Fe spins are revealed by elastic neutron scattering. The resultant incommensurability {delta} is unexpectedly large (-0.2 r.l.u.), as compared with {delta}-1/8 in overdoped superconductor La{sub 2-x}Sr{sub x}CuO{sub 4}. Intriguingly, the large {delta} in this overdoped region is close to the hole concentration p. This result is reminiscent of the {delta}{approx}p trend observed in underdoped La{sub 2-x}Sr{sub x}CuO{sub 4}; however, it is inconsistent with the saturation of {delta} in the latter compound in the overdoped regime. While our findings in Fe-doped Bi{sub 1.75}Pb{sub 0.35}Sr{sub 1.90}CuO{sub 6+z} support the commonality of incommensurate spin correlations in high-T{sub c} cuprate superconductors, they also suggest that the magnetic response might be dominated by a distinct mechanism in the overdoped region.

  13. Magnetic States of the Co-ions in Ca and Y Doped (Bi,Pb2Sr2Co2O8 Thermoelectric Materials

    Directory of Open Access Journals (Sweden)

    Inge M. Sutjahja

    2012-11-01

    Full Text Available The magnetic states of Cobalt ions in magnetic thermoelectric materials of Bi1.5Pb0.5Ca2-zYzCo2O8 (z = 0, 0.1, 0.2, and 0.3 have been studied from the structural (X-ray diffraction and magnetic susceptibility data. The misfit structure was revealed from refinement of the XRD data, with reduction of the lattice parameters while increasing the Y doping content. Compared with the (Bi,Pb2Sr2Co2O8 parent compound system, the lattice parameter c was reduced significantly, while the misfit degree remained almost the same. The analysis of the magnetic data shows that the Cobalt ions are coupled antiferromagnetically within the CoO2 layers, with the existence of mixed valence states between Co3+ and Co4+ ions. Besides that, the effective magnetic moments of Cobalt ions are almost constant along the Y doping content. Assuming the orbital quenching as commonly found in most transition metal ions, the data are best fitted by taking the low-spin state of Co3+ ions and intermediate spin state of Co4+ ions. We argue qualitatively, that the spin-state transition across the gap are induced by the shrinkage of the charge transfer energy gaps between O 2p and Co levels due to reduction of the ionic spaces between Co and O ions.

  14. PB@Au Core-Satellite Multifunctional Nanotheranostics for Magnetic Resonance and Computed Tomography Imaging in Vivo and Synergetic Photothermal and Radiosensitive Therapy.

    Science.gov (United States)

    Dou, Yan; Li, Xue; Yang, Weitao; Guo, Yanyan; Wu, Menglin; Liu, Yajuan; Li, Xiaodong; Zhang, Xuening; Chang, Jin

    2017-01-18

    To integrate multiple diagnostic and therapeutic strategies on a single particle through simple and effective methods is still challenging for nanotheranostics. Herein, we develop multifunctional nanotheranostic PB@Au core-satellite nanoparticles (CSNPs) based on Prussian blue nanoparticles (PBNPs) and gold nanoparticles (AuNPs), which are two kinds of intrinsic theranostic nanomaterials, for magnetic resonance (MR)-computed tomography (CT) imaging and synergistic photothermal and radiosensitive therapy (PTT-RT). PBNPs as cores enable T1- and T2-weighted MR contrast and strong photothermal effect, while AuNPs as satellites offer CT enhancement and radiosensitization. As revealed by both MR and CT imaging, CSNPs realized efficient tumor localization by passively targeted accumulation after intravenous injection. In vivo studies showed that CSNPs resulted in synergistic PTT-RT action to achieve almost entirely suppression of tumor growth without observable recurrence. Moreover, no obvious systemic toxicity of mice confirmed good biocompatibility of CSNPs. These results raise new possibilities for clinical nanotheranostics with multimodal diagnostic and therapeutic coalescent design.

  15. Production of BiPbSrCaCuO thin films on MgO and Ag/MgO substrates by electron beam deposition techniques

    CERN Document Server

    Varilci, A; Gorur, O; Celebi, S; Karaca, I

    2002-01-01

    Superconducting BiPbSrCaCuO thin films were prepared on MgO(001) and Ag/MgO substrates using an electron beam (e-beam) evaporation technique. The effects of annealing temperature and Ag diffusion on the crystalline structure and some superconducting properties, respectively, were investigated by X-ray diffraction, atomic force microscopy, and by measurements of the critical temperature and the critical current density. It was shown that an annealing of both types of films at 845 or 860 C resulted in the formation of mixed Bi-2223 and Bi-2212 phases with a high degree of preferential orientation with the c-axis perpendicular to the substrates. The slight increase of the critical temperature from 103 K to 105 K, the enhancement of the critical current density from 2 x 10 sup 3 to 6 x 10 sup 4 A/cm sup 2 , and the improved surface smoothness are due to a possible silver doping from the substrate. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  16. Arsenic and heavy metal contamination and their seasonal variation in the paddy field around the Daduk Au-Pb-Zn mine in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Churl-Gyu [Korea Petroleum Association, Seoul(Korea); Chon, Hyo-Taek [Seoul National University, Seoul(Korea); Jung, Myung Chae [Semyung University, Jecheon(Korea)

    2000-02-28

    Arsenic and heavy metal contamination, seasonal variation of the metal contents in soils and plants and their migration characteristics from soils into plants in the vicinity of the abandoned Daduk Au-Pb-Zn mine were studied. Soils collected downstream from the mine show high contents of As and heavy metals due to surface erosion and wind blowing in the tailings. However, their contamination was limited around the old dressing plant and paddy field nearby the polluted stream. Enriched concentrations of Cd and Zn were found in various agricultural crops grown in the paddy fields nearby the mine site, and Zn was accumulated specially in soybean leaves. Elevated level of As was also found in rice stalks and leaves. Biological absorption coefficients of the crop plants for heavy metals decreased in the order of soybean leaves, red peppers, rice stalks and leaves, and rice grain, and were higher for Cd and Cu than Pb and Zn. Seasonal variation of As and heavy metals in paddy fields showed that relatively higher concentrations and biological absorption coefficients were found in rice stalks and leaves grown under oxidizing conditions in September rather than under reducing conditions in August, especially for As, Cd, Pb and Zn. It is suggested that the amount of As and heavy metals absorbed by rice crops might be changed under the different condition of paddy fields throughout the period of growing. (author). 26 refs., 6 tabs., 8 figs.

  17. The crystal structure of Cu1.6Pb1.6Bi6.4S12, a new 44.8 Å derivative of the bismuthinite-aikinite solid-solution series

    DEFF Research Database (Denmark)

    Topa, Dan; Balic-Zunic, Tonci; Makovicky, Emil

    2000-01-01

    Cu1.6Pb1.6Bi6.4S12, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria......Cu1.6Pb1.6Bi6.4S12, aikinite-bismuthinite derivative, crystal structure, Felbertal, scheelite deposit, Austria...

  18. Improvement of Bi-2223/Ag tape performances through the control of the Pb-rich phases present in the precursors powders

    DEFF Research Database (Denmark)

    Chen, X.P.; Grivel, Jean-Claude; Li, M.Y.;

    2004-01-01

    Precursor powders containing different lead-rich phases: (a) Ca2PbO4, (b) Pb-3(Sr,Bi)(3)Ca2CuOy (3321), were prepared by controlling the calcination temperature and atmosphere. Monofilament tapes were fabricated using those two powders. It has been found that both the microstructure and critical...... current depended strongly on the nature of the lead-rich phase. Tapes fabricated using the precursor with the Ca2PbO4 phase (tape T1) had a much lower optimum sintering temperature and a narrower temperature window than tapes fabricated using the precursor with the 3321 phase (tape T2). The critical...... current density J(c), of tape T2 is improved by a factor 1.5-2. SEM results show that a large fraction of secondary phases with big particle size was formed in the fully reacted tape TI, which might degrade the critical current of these tapes. On the contrary, little and small secondary phases were formed...

  19. Radiochemical neutron activation analysis for 36 elements in geological material: Au, Ag, Bi, Br, Cd, Cs, Ge, In, Ir, Ni, Os, Pd, Rb, Re, Sb, Se, Sn, Te, Tl, U, and Zn as well as Sc, Y, and REE

    Energy Technology Data Exchange (ETDEWEB)

    Anders, E; Wolf, R; Morgan, J W; Ebihara, M; Woodrow, A B; Janssens, M J; Hertogen, J

    1988-01-01

    In lunar and terrestrial rocks and in meteorites, the radiochemical neutron activation method decribed here enables determination of the 21 trace and ultratrace elements Ag, Au, Bi, Br, Cd, Cs, Ga, Ge, In, Ir, Ni, Os, Pd, Rb, Re, Sb, Se, Te, Tl, U, Zn, as well as 13 rare earth elements (REE), Sc and Y. Materials, techniques and procedures are discussed. 81 refs.

  20. The effect of multilayered Bi1.8Pb0.4Ca2.2Sr2Cu3Ox/Ag on superconducting and microstructure properties of Bi1.8Pb0.4Ca2.2Sr2Cu3Ox

    Science.gov (United States)

    Akdogan, Mustafa; Terzioglu, Cabir; Belenli, Ibrahim

    2010-03-01

    A precursor powder with a nominal chemical composition of Bi1.8Pb0.4Ca2.2Sr2Cu3Ox was used to fabricate the multilayered Bi1.8Pb0.4Ca2.2Sr2Cu3Ox/Ag samples (number of layers was 2, 4 and 8) using the powder-in-tube method (PIT). The density of powder increases during the drawing procedure and inside the composite wires of the final diameter is 3.54 mm. By an intermediate rolling, pressing and annealing procedure, the wires were rolled to obtain tapes. The rolling process was not effective in obtaining further substantially increase of the powder density, but greatly improved the orientation of ceramic grains inside the silver sheath. The sample is composed of a highly oriented Bi-2223 phase in the region near to the Ag layer. The eight-layered sample exhibits a rather high Ic value of 110 A. Tc and Jc are enhanced by increasing the number of Ag layers. The formation of the dense oriented structure is near the interface between oxide and the Ag layer. This suggests that Ag plays an important role in the improvement of Jc.

  1. Triangular flow of negative pions emitted in PbAu collisions at $\\sqrt{s_{NN}} $= 17.3~GeV

    CERN Document Server

    Adamová, D.

    Differential triangular flow, $v_3(p_T)$, of negative pions is measured at $\\sqrt{s_{NN}}$= 17.3~GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0-30\\% with a mean centrality of 5.5\\%. This is the first measurement of the triangular flow at SPS energies. The $p_T$ range extends from about 0.05~GeV/c to more than 2~GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydro calculation combined with an UrQMD cascade model for the late stages.

  2. The Forming Conditions of and Ore- searching Direction for B, Mg, Pb, Zn and Au Deposits in the Liaoji Proterozoic Rift

    Institute of Scientific and Technical Information of China (English)

    Zhu Yongzheng; Yao Fengliang

    2001-01-01

    The Liaoji Proterozoic rift is an inter- intracontinenatl rift developed from Archean granite- greenstone tectonic regime and contains many important mineral deposits of U, B, magnesite, Pb - Zn, Au, Ag, Co and P. These deposits were formed as the result of late mobilization, transportation and concentration of the previously enriched ore - forming materials in several ore- bearing formations formed during the rift stage. So the metallogeny of these deposits in the rift shows both inheritance and new generation of the ore - forming materials. In future ore - searching practice, attentions should be paid on the studies of the ore - bearing formations in the rift, on the multiple stages of metallogeny and and on multiple derivations of the ore - forming materials.

  3. DISLOCATIONS MOBILITY UNDER THE IMAGE FORCE EFFECT IN BICRYSTALS OF CFC MATERIALS: CU-X, X = PB, AL, AU, AG AND NI

    Directory of Open Access Journals (Sweden)

    A OUCHTATI

    2015-06-01

    Full Text Available The image force undergone by a matrix dislocations close and parallel to an interphase boundary is studied in Cu-X bicrystals (with X = Pb, Al, Au, Ag, Ni for disorientations ranging between 0° and 90°.  Dislocations have a Burgers vector  = a/2 [110]. The elastic energy of dislocation-boundary interaction is calculated within the framework of anisotropic linear elasticity. The elastic energy is related to the difference of the two metals shear moduli. It is about a few hundred pico Joule per meter. The image force can be repulsive or attractive according to the sign and the intensity of shear moduli difference. The isoenergy maps have various symmetries according to the disorientation.

  4. Search for Charged Strange Quark Matter Produced in 11.5{ital A} GeV/{ital c} Au+Pb Collisions

    Energy Technology Data Exchange (ETDEWEB)

    De Cataldo, G.; Giglietto, N.; Raino, A.; Spinelli, P. [University of Bari/INFN, Bari (Italy); Dover, C.B. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Huang, H.Z. [University of California at Los Angeles, Los Angeles, California 90095 (United States); Hill, J.C.; Hoversten, R.A.; Libby, B.; Wohn, F.K. [Iowa State University, Ames, Iowa 50011 (United States); Rabin, M.S. [University of Massachusetts, Amherst, Massachusetts 01003 (United States); Haridas, P.; Pless, I.A.; Van Buren, G. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Armstrong, T.A.; Lewis, R.A.; Reid, J.D.; Smith, G.A.; Toothacker, W.S. [Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Davies, R.; Hirsch, A.S.; Porile, N.T.; Rimai, A.; Scharenberg, R.P.; Srivastava, B.K.; Tincknell, M.L. [Purdue University, West Lafayette, Indiana 47907 (United States); Lainis, T. [United States Military Academy, West Point, New York 10996 (United States); Greene, S.V. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Bennett, S.J.; Cormier, T.M.; Dee, P.; Fachini, P.; Kim, B.; Li, Q.; Munhoz, M.G.; Pruneau, C.A.; Wilson, W.K.; Zhao, K. [Wayne State University, Detroit, Michigan 48201 (United States); Barish, K.N.; Bennett, M.J.; Chikanian, A.; Coe, S.D.; Diebold, G.E.; Finch, L.E.; George, N.K.; Kumar, B.S.; Lajoie, J.G.; Majka, R.D.; Nagle, J.L.; Pope, J.K.; Rotondo, F.S.; Sandweiss, J.; Slaughter, A.J.; Wolin, E.J.; Xu, Z. [Yale University, New Haven, Connecticut 06520 (United States)

    1997-11-01

    We present results of a search for strange quark matter (strangelets) in 11.5A GeV /c Au+Pb collisions from the 1994 and 1995 runs of experiment E864 at Brookhaven{close_quote}s Alternating Gradient Synchrotron. We observe no strangelet candidates and set a 90{percent} confidence level upper limit of approximately 3{times}10{sup {minus}8} per 10{percent} central interaction for the production of {vert_bar}Z{vert_bar}=1 and {vert_bar}Z{vert_bar}=2 strangelets over a large mass range and with metastable lifetimes of about 50ns or more. These results place constraints primarily on quark-gluon plasma based production models for strangelets. {copyright} {ital 1997} {ital The American Physical Society}

  5. Effectively control negative thermal expansion of single-phase ferroelectrics of PbTiO3-(Bi,La)FeO3 over a giant range.

    Science.gov (United States)

    Chen, Jun; Wang, Fangfang; Huang, Qingzhen; Hu, Lei; Song, Xiping; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

    2013-01-01

    Control of negative thermal expansion is a fundamentally interesting topic in the negative thermal expansion materials in order for the future applications. However, it is a challenge to control the negative thermal expansion in individual pure materials over a large scale. Here, we report an effective way to control the coefficient of thermal expansion from a giant negative to a near zero thermal expansion by means of adjusting the spontaneous volume ferroelectrostriction (SVFS) in the system of PbTiO3-(Bi,La)FeO3 ferroelectrics. The adjustable range of thermal expansion contains most negative thermal expansion materials. The abnormal property of negative or zero thermal expansion previously observed in ferroelectrics is well understood according to the present new concept of spontaneous volume ferroelectrostriction. The present studies could be useful to control of thermal expansion of ferroelectrics, and could be extended to multiferroic materials whose properties of both ferroelectricity and magnetism are coupled with thermal expansion.

  6. Piezoelectric properties of low loss and high Curie temperature (Bi, La)FeO_3-Pb(Ti, Mn)O_3 ceramics with Mn doping

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Piezoelectric ceramics of 0.6(Bi0.9La0.1)FeO3-0.4Pb(Ti1-xMnx)O3 (BLF-PTM) for x=0, 0.01, 0.02, and 0.03 were prepared by sol-gel process combined with a solid-state reaction method. The tan? for BLF-PTM of x=0.01 is just 0.006 at 1 kHz, drastically decreasing by using Mn dopants. The TC increases to 490 ℃ for BLF-PTM of x=0.02. Furthermore, Mn modification effectively enhances the poling state and the piezoelectric properties of BLF-PTM. The kp, Qm, d33, and g33 of 0.34, 403, and 124 pC1·N-1 and 37×10-3 Vm·...

  7. Intragrain pinning strength depth dependence of 2223 (Bi,Pb)-based high critical Tc superconducting ceramics made by a vitreous route

    Science.gov (United States)

    Dang, An; Godelaine, P. A.; Vanderbemden, Ph.; Cloots, R.; Ausloos, M.

    1995-04-01

    Campbell's method for measuring the critical current in superconductors has been used to obtain the critical current density and the pinning strength in Bi1.7Pb0.3Sr2Ca2Cu3O10-y ceramics synthesized by a vitreous route. The intragrain critical current is much higher than 105 A/cm2 at 40 K in zero dc magnetic field. A large increase of the pinning strength is observed near the grain surface. The decrease with depth is hyperbolic. The role of the precursors in the synthesis route is emphasized for introducing specific pinning centers. The analysis takes into consideration the ceramics granular nature, i.e., the existence of intergrain and intragrain currents.

  8. Neutron-induced fission cross section of (nat)Pb and (209)Bi from threshold to 1 GeV: An improved parametrization

    CERN Document Server

    Tarrio, D; Audouin, L; Berthier, B; Duran, I; Ferrant, L; Isaev, S; Le Naour, C; Paradela, C; Stephan, C; Trubert, D; Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Badurek, G; Baumann, P; Becvar, F; Belloni, F; Berthoumieux, E; Calvino, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapico, C; Carrillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Eleftheriadis, C; Embid-Segura, M; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Kadi, Y; Kappeler, F; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lederer, C; Lindote, A; Lopes, I; Losito, R; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martinez, T; Massimi, C; Mastinu, P; Mendoza, E; Mengoni, A; Milazzo, P.M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M.T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Sarmento, R; Savvidis, I; Tagliente, G; Tain, J.L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross sections for (nat)Pb and (209)Bi were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n\\_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to (235)U and (238)U in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range.

  9. Quijarroite, Cu6HgPb2Bi4Se12, a New Selenide from the El Dragόn Mine, Bolivia

    Directory of Open Access Journals (Sweden)

    Hans-Jürgen Förster

    2016-11-01

    Full Text Available Quijarroite, ideally Cu6HgPb2Bi4Se12, is a new selenide species from the El Dragόn mine, Department of Potosí, Bolivia. It most frequently occurs as lath-shaped thin plates (up to 150 µm in length and 20 µm in width intimately (subparallel intergrown with hansblockite, forming an angular network-like intersertal texture. Quijarroite is occasionally also present as sub- to anhedral grains up to 200 µm in length and 50 µm in width. It is non-fluorescent, black and opaque with a metallic luster and black streak. It is brittle, with an irregular fracture and no obvious cleavage and parting. In plane-polarized incident light, quijarroite is weakly pleochroic from cream to very slightly more brownish-cream, displaying no internal reflections. Between crossed polars, quijarroite is moderately anisotropic with pale orange-brown to blue rotation tints. Lamellar twinning on {110} is common; parquet twinning occurs rarely. The reflectance values in the air for the COM (Commission on Ore Mineralogy standard wavelengths (R1 and R2 are: 46.7, 46.8 (470 nm, 47.4, 48.2 (546 nm, 47.1, 48.5 (589 nm, and 46.6, 48.7 (650 nm. Electron-microprobe analyses yielded a mean composition of Cu 13.34, Ag 1.02, Hg 7.67, Pb 16.87, Co 0.03, Ni 0.15, Bi 27.65, Se 33.52, total 100.24 wt %. The mean empirical formula, normalized to 25 apfu (atoms per formula unit, is (Cu5.84Ag0.26Σ = 6.10(Hg1.06Ni0.07Co0.01Σ = 1.14Pb2.27Bi3.68Se11.81 (n = 24. The simplified formula is Cu6HgPb2Bi4Se12. Quijarroite is orthorhombic, space group Pmn21, with a = 9.2413(8, b = 9.0206(7, c = 9.6219(8 Å, V = 802.1(1 Å3, Z = 1. The calculated density is 5.771 g·cm−3. The five strongest X-ray powder-diffraction lines (d in Å (I/I0 (hkl are: 5.36 (55 (111, 3.785 (60 (211, 3.291 (90 (022, 3.125 (100 (212, and 2.312 (50 (400. The crystal structure of quijarroite can be considered a galena derivative and could be derived from that of bournonite. It is a primary mineral, deposited from an

  10. Numerical simulation and experimental study of PbWO4/EPDM and Bi2WO6/EPDM for the shielding of {\\gamma}rays

    CERN Document Server

    Song, Chi; Zhang, Quanping; Li, Yintao; Li, Yingjun; Zhou, Yuanlin

    2016-01-01

    The MCNP5 code was employed to simulate the {\\gamma}ray shielding capacity of tungstate composites. The experimental results were applied to verify the applicability of the Monte Carlo program. PbWO4 and Bi2WO6 were prepared and added into ethylene propylene diene monomer (EPDM) to obtain the composites, which were tested in the {\\gamma}ray shielding. Both the theoretical simulation and experiments were carefully chosen and well designed. The results of the two methods were found to be highly consistent. In addition, the conditions during the numerical simulation were optimized and double-layer {\\gamma}ray shielding systems were studied. It was found that the {\\gamma}-ray shielding performance can be influenced not only by the material thickness ratio but also by the arrangement of the composites.

  11. Physiological studies of environmental pollutants. Progress report, September 1, 1975--May 31, 1976. [/sup 210/Po, /sup 203/Pb, /sup 201/Tl, /sup 207/Bi, /sup 65/Zn

    Energy Technology Data Exchange (ETDEWEB)

    Lengemann, F W; Wentworth, R A

    1976-01-01

    In the past year we have looked at the transfer of some members of the actinide decay series into milk of goats. These were /sup 210/Po, /sup 203/Pb, /sup 201/Tl and /sup 207/Bi. All of these appeared in milk after oral ingestion but at levels less than 1 percent per liter. In addition we have looked at the transfer of /sup 65/Zn into milk of goats after oral and I.V. doses; the experiments are incomplete at this time. In controlled temperature studies it was found that 6.6 times as much radioiodine was secreted into milk when goats were at 33/sup 0/ as opposed to 5/sup 0/C. When radioiodine is put into the mammary gland the transfer from milk to body is rapid; more rapid than is the case for /sup 65/Zn. The analysis of these data indicate the need for a model capable of handling expansion of a compartment.

  12. Progress report on neutron beam experiments in Thailand: effects of antimony substitutions on the critical temperature of Bi-Pb-Sr-Ca-Cu-O compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sangariyavanich, A.; Ampornrat, P. [Office of Atomic Energy for Peace, Bangkok (Thailand)

    1998-10-01

    Effects of systematic substitutions of antimony for bismuth in Bi{sub 1.8-x}Pb{sub 0.2}Sb{sub x}Sr{sub 2}Ca{sub 3}Cu{sub 4}O{sub 10} have been investigated. Fabrication of the specimens has been performed by solid state reaction in air. The samples were sintered between 820degC - 843degC for 65 hours and subsequently quenched in liquid nitrogen. The critical temperatures of most specimens as determined by standard four-probe technique was higher than 100 K. Phase identification by X-ray diffraction technique indicated that `2223` and `2234` were the predominant phases in these samples. (author)

  13. Gamma ray shielding and structural properties of Bi2O3-PbO-B2O3-V2O5 glass system

    Science.gov (United States)

    Kaur, Kulwinder; Singh, K. J.; Anand, Vikas

    2014-04-01

    The present work has been undertaken to evaluate the applicability of Bi2O3-PbO-B2O3-V2O5 glass system as gamma ray shielding material. Gamma ray mass attenuation coefficient has been determined theoretically using WinXcom computer software developed by National Institute of Standards and Technology. A meaningful comparison of their radiation shielding properties has been made in terms of their half value layer parameter with standard radiation shielding concrete 'barite'. Structural properties of the prepared glass system have been investigated in terms of XRD and FTIR techniques in order to check the possibility of their commercial utility as alternate to conventional concrete for gamma ray shielding applications.

  14. Highly (110)- and (111)-oriented BiFeO3 films on BaPbO3 electrode with Ru or Pt /Ru barrier layers

    Science.gov (United States)

    Lee, Chia-Ching; Wu, Jenn-Ming; Hsiung, Chang-Po

    2007-04-01

    Highly (110)- and (111)-oriented BiFeO3 (BFO) films were fabricated with BaPbO3 (BPO )/Ru and BPO /Pt/Ru as electrode/barrier on Si substrates by rf-magnetron sputtering. The BPO /Ru and BPO /Pt/Ru stacks both induce oriented BFO films and act as diffusion barriers. The (110)- and (111)-oriented BFO films possess excellent ferroelectric properties with only minor leakage. The values of remnant polarization are almost the same, about 42μC/cm2, for (110)- and (111)-oriented BFO films. However, polarization measured under varying pulse widths demonstrates that the switching polarization in (111)-oriented BFO films is higher than in (110)-oriented films. Additionally, (111)-oriented BFO films exhibit better retention properties than (110)-oriented films.

  15. Highly sensitive photodetection using a microwave-coupled BaPb0.7Bi0.3O3 Josephson junction array

    Science.gov (United States)

    Ito, Minoru; Enomoto, Youichi; Murakami, Toshiaki

    1983-08-01

    The BaPb0.7Bi0.3O3 sputtered film possesses tunnel Josephson junctions at boundary layers [boundary Josephson junction (BJJ)] normal to the film plane in a homogeneous junction array. The film has high efficiency for optical irradiation of the junctions because of the high optical transparency. The letter presents the optical effect on the current-voltage characteristics for this Josephson junction array locked to a microwave field. The microwave-induced hysteresis loop caused by voltage locking among junctions in a microwave field is highly sensitive to optical illumination with as low an incident power as a few nanowatts. This probably can be exploited in a future, highly sensitive photodetector.

  16. The crystal structure of gustavite, PbAgBi3S6. Analysis of twinning and polytypism using the OD approach

    DEFF Research Database (Denmark)

    Makovicky, Emil; Topa, Dan

    2011-01-01

    The crystal structure of gustavite Pb1.06Ag0.95Bi2.80Sb0.20S5.99 from Rotgu¨lden, Lungau, Salzburg Land, Austria, was refined to R1 ¼ 2.76 % using single-crystal X-ray diffraction data. Refined unit-cell parameters are a 7.0567(14), b 19.6905(39), c 8.2219(16) A ° , b 106.961(3) , unit-cell volume...... and the interlayer symmetry elements {(22/n1,1/2) 21/n1/2,2 21/2/ a2}. An alternative OD description uses planar unit layers with the layer symmetry P(2/ b) 21/c 21/m and the interlayer elements 22/n1,–1/2 21/n1/2,2 21/2/a2. The former description adheres closely to the details of coordination of bismuth observed...

  17. Large Electric-Field Modulation of Magnetic Properties in Fe Films on BiScO3-PbTiO3 Ceramics

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2010-01-01

    Full Text Available Based on the magneto-optical Kerr effect, we report the electric-field modulation of the magnetic properties in Fe/BiScO3-PbTiO3 (BSPT film-on-ceramic substrate structure. The Fe films are directly grown on the fully-poled BSPT ceramic substrates by magnetron sputtering. An electric field applied parallel to the prepolarization direction of the piezoelectric BSPT can induce a reversible increase in the coercive field Hc of about 30%, whereas an electric field antiparallel to the prepolarization direction can cause a persistent, tremendous decrease (as large as 97% in Hc, and a small reversal electric field can resume it back. The strain induced by the inverse piezoelectric effect is the primary mechanism behind. This large modulation of the coercive field by the electric field could inspire further exploration of electric-field-controlled magnetic switching in multiferroic heterostructures.

  18. Production cross sections of discrete gamma-ray resulting from interaction of 14. 2 MeV neutron with Pb and Bi

    Energy Technology Data Exchange (ETDEWEB)

    Wu Youngshun; Shen Ronglin; Shi Xiamin; Xing Jinqiang; Ding Dazhao

    1982-11-01

    The differential cross sections of gamma-rays produced in interation of 14.2 MeV neutron with natural lead and bismuth have been measured at 55/sup 0/ (lab). The complete shield Ge (Li) spectrometer with time-of-flight technique gated by associated particle in T(d,n) reaction was used. The gamma-ray spectra from 14.2 MeV neutron interactions with /sup 238/U and natural Tungsten have been measured as well. For Pb and Bi, tens of discrete gamma-rays were identified. Some of thme have not been reported in previous work. The effects of attenuation and multiple scattering of neutron and the gamma-ray self-absorption in sample are corrected by Monte-Carlo method. The experimental results are compared with others.

  19. Composite metallic sheathes: the key to low-cost, high strength (Bi,Pb)2Sr2Ca2Cu3O10-based tapes?

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2007-01-01

    (Bi, Pb)(2)Sr2Ca2Cu3O10-based superconducting tapes were prepared by the powder- in- tube process, using a bimetallic sheath consisting of Ag and Ni. Ag was in contact with the superconducting ceramic core and acted as a protective layer against reaction between the external Ni sheath and the core......(e) of about 11 000 A cm(-2), were achieved in a single heat-treatment. The efficient protection offered by the Ag layer against Ni diffusion into the ceramic core suggests that Ag layers as thin as 5 mu m may be applied, thus reducing the production costs. The superior stiffness of Ni provides a stronger...

  20. Structure and magnetic properties of a new anion-deficient perovskite Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} with crystallographic shear structure

    Energy Technology Data Exchange (ETDEWEB)

    Batuk, Maria, E-mail: Maria.Batuk@ua.ac.be [Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp (Belgium); Tyablikov, Oleg A. [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation); Tsirlin, Alexander A. [National Institute of Chemical Physics and Biophysics, 12618 Tallinn (Estonia); Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden (Germany); Kazakov, Sergey M.; Rozova, Marina G.; Pokholok, Konstantin V.; Filimonov, Dmitry S.; Antipov, Evgeny V. [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation); Abakumov, Artem M. [Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp (Belgium); Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation); Hadermann, Joke [Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp (Belgium)

    2013-09-01

    Graphical abstract: - Highlights: • Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} was obtained by solid state synthesis. • Its structure was refined from combination of XPD and TEM. • It is a new member of the perovskite-related homologous series A{sub n}B{sub n}O{sub 3n−2} with n = 5. • Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} is antiferromagnetically ordered below T{sub N} ≈350 K. - Abstract: Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13}, a new n = 5 member of the oxygen-deficient perovskite-based A{sub n}B{sub n}O{sub 3n−2} homologous series, was synthesized using a solid-state method. The crystal structure of Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} was investigated by a combination of synchrotron X-ray powder diffraction, electron diffraction, high-angle annular dark-field scanning transmission electron microscopy and Mössbauer spectroscopy. At 900 K, it crystallizes in the Ammm space group with the unit cell parameters a = 5.8459(1) Å, b = 4.0426(1) Å, and c = 27.3435(1) Å. In the Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} structure, quasi-two-dimensional perovskite blocks are periodically interleaved with ½[1 1 0] (1{sup ¯}01){sub p} crystallographic shear (CS) planes. At the CS planes, the corner-sharing FeO{sub 6} octahedra are transformed into chains of edge-sharing FeO{sub 5} distorted tetragonal pyramids. B-positions of the perovskite blocks between the CS planes are jointly occupied by Fe{sup 3+} and Sc{sup 3+}. The chains of the FeO{sub 5} pyramids and (Fe,Sc)O{sub 6} octahedra delimit six-sided tunnels that are occupied by double columns of cations with a lone electron pair (Pb{sup 2+}). The remaining A-cations (Bi{sup 3+}, Ba{sup 2+}) occupy positions in the perovskite block. According to the magnetic susceptibility measurements, Pb{sub 2}Ba{sub 2}BiFe{sub 4}ScO{sub 13} is antiferromagnetically ordered below T{sub N} ≈350 K.

  1. Residual tensile stresses and piezoelectric properties in BiFeO3-Bi(Zn1/2Ti1/2O3-PbTiO3 ternary solid solution perovskite ceramics

    Directory of Open Access Journals (Sweden)

    Weilin Zheng

    2016-08-01

    Full Text Available For low dielectric loss perovskite-structured (1-x-yBiFeO3-xBi(Zn1/2Ti1/2O3-yPbTiO3 (BF-BZT-PT (x = 0.04-0.15 and y = 0.15-0.26 ceramics in rhombohedral/tetragonal coexistent phase, structural phase transitions were studied using differential thermal analyzer combined with temperature-dependent dielectric measurement. Two lattice structural phase transitions are disclosed in various BF-BZT-PT perovskites, which is different from its membership of BiFeO3 exhibiting just one lattice structural phase transition at Curie temperature TC= 830oC. Consequently, residual internal tensile stresses were revealed experimentally through XRD measurements on ceramic pellets and counterpart powders, which are reasonably attributed to special structural phase transition sequence of BF-BZT-PT solid solution perovskites. Low piezoresponse was observed and argued extrinsically resulting from residual tensile stresses pinning ferroelectric polarization switching. Post-annealing and subsequent quenching was found effective for eliminating residual internal stresses in those BZT-less ceramics, and good piezoelectric property of d33 ≥ 28 pC/N obtained for 0.70BF-0.08BZT-0.22PT and 0.05 wt% MnO2-doped 0.70BF-0.04BZT-0.26PT ceramics with TC ≥ 640oC, while it seemed no effective for those BZT-rich BF-BZT-PT ceramics with x = 0.14 and 0.15 studied here.

  2. Diffusion coefficients for Tl, Pb, Cd, In, Zn, Bi, As, Mo and Sb in hydrous rhyolite at 100-200 MPa

    Science.gov (United States)

    Berlo, Kim; Brooker, Richard; Wilke, Max

    2014-05-01

    A series of experiments have been conducted to determine the diffusivities of Tl, Pb, Cd, In, Zn, Bi, As, Mo and Sb in hydrous rhyolitic melt. Diffusion experiments used two adjoining glass cylinder of the same hydrous composition, one doped with the elements of interest at ~ 100 ppm. These couples were rapidly heated to 850, 1000 and 1150°C at 100-200 MPa for a few hours. After quenching the sectioned charges were analyzed by both synchrotron XRF (The Diamond Light Source) and LA-ICP-MS (University of Oxford). The data shows excellent correlation between these two techniques. The diffusion profiles were fitted to a 1-D diffusion couple equation to determine the diffusivities and fitting to the different temperature runs defined the Arrhenius parameters. We find that for 850°C the diffusion coefficients follow the trend Tl>Pb>Cd>Zn>In>Bi>As>Sb>Mo. Additional experiments were performed with either S or Cl added (to both sides of the diffusion couple). In general S increases the diffusion rate of all metals except Mo and Sb, which diffuse slower in the presence of S. Chlorine also speeds up the diffusion of metals with the exception of In, Mo and Sb. The systematic change in diffusivities of these metals and their different behaviour in the presence of the ligands that are also observed to be significant in volcanic gases, are important in determining the distribution of these metals during degassing (e.g. MacKenzie and Canil, 2008). This is particularly important in a dynamic environment such as a volcanic conduit. There are also implications for economic exploration and well as hazard mitigation.

  3. Effect of Ag additions on the Bi1.6Pb0.4Sr2Co1.8Ox thermoelectric properties

    Directory of Open Access Journals (Sweden)

    Diez, J. C.

    2013-04-01

    Full Text Available Bi1.6Pb0.4Sr2Co1.8Ox thermoelectric ceramics with small Ag additions (0, 1, and 3 wt.% have been successfully produced by a sol-gel method via nitrates. Microstructure has shown a reduction on the amount of secondary phases and an increase on the bulk density with increasing Ag contents. The microstructural evolution, as a function of Ag content, is confirmed with the electrical resistivity values which show an important decrease for the 3 wt.% Ag samples, leading to maximum power factor values of about 0.025 mW/K2.m at room temperature, which is about two times higher than the obtained for the Ag-free sintered samples.Se han preparado cerámicas termoeléctricas de composición Bi1.6Pb0.4Sr2Co1.8Ox con pequeñas adiciones de Ag (0, 1, y 3 % en peso por medio de un método sol-gel a partir de los nitratos metálicos. La microestructura ha mostrado una reducción de la cantidad de fases secundarias y un aumento de la densidad del material al aumentar la cantidad de Ag. La evolución microestructural, en función del contenido de Ag, se ha confirmado con los valores de la resistividad eléctrica que muestra una reducción importante para las muestras con 3 % en peso de Ag, lo que lleva a alcanzar valores máximos del factor de potencia de alrededor de 0.025 mW/K2.m a temperatura ambiente, que es dos veces mayor que el obtenido para muestras sinterizadas sin Ag.

  4. Evaluation of Bi as internal standard to minimize matrix effects on the direct determination of Pb in vinegar by graphite furnace atomic absorption spectrometry using Ru permanent modifier with co-injection of Pd/Mg(NO 3) 2

    Science.gov (United States)

    de Oliveira, Silvana Ruella; Neto, José Anchieta Gomes

    2007-09-01

    Bismuth was evaluated as an internal standard for the direct determination of Pb in vinegar by graphite furnace atomic absorption spectrometry using Ru as a permanent modifier with co-injection of Pd/Mg(NO 3) 2. The correlation coefficient of the graph plotted from the normalized absorbance signals of Bi versus Pb was r = 0.989. Matrix effects were evaluated by analyzing the slope ratios between the analytical curve obtained from reference solutions prepared in 0.2% (v/v) HNO 3 and analytical curves obtained from Pb additions in red and white wine vinegar samples. The calculated ratios were around 1.04 and 1.02 for analytical curves established applying an internal standard and 1.3 and 1.5 for analytical curves without. Analytical curves in the 2.5-15 μg L - 1 Pb concentration interval were established using the ratio Pb absorbance to Bi absorbance versus analyte concentration, and typical linear correlations of r = 0.999 were obtained. The proposed method was applied for direct determination of Pb in 18 commercial vinegar samples and the Pb concentration varied from 2.6 to 31 μg L - 1 . Results were in agreement at a 95% confidence level (paired t-test) with those obtained for digested samples. Recoveries of Pb added to vinegars varied from 96 to 108% with and from 72 to 86% without an internal standard. Two water standard reference materials diluted in vinegar sample were also analyzed and results were in agreement with certified values at a 95% confidence level. The characteristic mass was 40 pg Pb and the useful lifetime of the tube was around 1600 firings. The limit of detection was 0.3 μg L - 1 and the relative standard deviation was ≤ 3.8% and ≤ 8.3% ( n = 12) for a sample containing 10 μg L - 1 Pb with and without internal standard, respectively.

  5. Piezoresponse Force Microscopy Imaging of Ferroelectric Domains in Bi(Zn1/2Ti1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 Piezoelectric Ceramics

    Institute of Scientific and Technical Information of China (English)

    LIU Li-Ming; ZENG Hua-Bong; CAO Zhen-Zhu; LENG Xue; ZHAO Kun-Yu; LI Guo-Rong; YIN Qing-Rui

    2011-01-01

    @@ Bismuth zinc titanate dopied lead magnesium niobate-lead titanate[Bi(Zn1/2Ti1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (BZT-PMN-PT)]piezoelectric ceramics are synthesized by the conventional solid state reaction method.Ferroelectric domain structures and the evolutionary behavior of BZT-PMN-PT ceramics under an external in-plane electric field are investigated by piezoresponse force microscopy(PFM).It is found that the BZT doping has a significant effect on the domain configurations and the domain kinetic behavior of the piezoelectric BZT-PMN-PT solid solution ceramics.Microdomains embedded in the macrodomains, induced by the BZT dopant in the solid solution ceramics, are clearly observed by PFM and their volume increases with increasing amounts of BZT doping.The microdomains of BZT-PMN-PT piezoelectric ceramics exhibit better domain dynamic behavior stability than macrodomains under an external in-plane electric held.

  6. Ferroelectric, piezoelectric, and dielectric properties of BiScO3-PbTiO3-Pb(Cd1/3Nb2/3)O3 ternary high temperature piezoelectric ceramics

    Science.gov (United States)

    Zhao, Tian-Long; Chen, Jianguo; Wang, Chun-Ming; Yu, Yang; Dong, Shuxiang

    2013-07-01

    (0.95-x)BiScO3-xPbTiO3-0.05Pb(Cd1/3Nb2/3)O3 (BS-xPT-PCN) high temperature piezoelectric ceramics near the morphotropic phase boundary (MPB) have been synthesized by traditional solid-state reaction methods. The microstructural morphology, phase structure, and electrical properties of BS-xPT-PCN ceramics were investigated in detail. X-ray diffraction analysis indicated BS-xPT-PCN ceramics have a pure perovskite structure. The coexistence of rhombohedral and tetragonal phases at MPB composition enhanced the polarizability by the coupling between two dynamically equivalent energy states, resulting in the improved piezoelectric and ferroelectric properties at MPB vicinity. The BS-xPT-PCN (x = 0.60) ceramics possess the optimal piezoelectric and ferroelectric properties with d33 = 505pC/N, kp = 55.9%, kt = 36.5%, strain = 0.23% (under the electric field 37.5 kV/cm), and Pr = 39.7 μC/cm2. High temperature dielectric behaviors showed diffuse phase transition in BS-xPT-PCN ceramics. The Curie temperature Tc was found to increase from 371 °C to 414 °C with x increasing from 0.58 to 0.62. All these results together with the good thermal stabilities make the BS-xPT-PCN ceramics promising candidates for high temperature piezoelectric applications.

  7. Structural and electronic properties of Pb-doped Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}: Comparison of LDA and GGA calculations

    Energy Technology Data Exchange (ETDEWEB)

    Camargo-Martínez, J.A., E-mail: jcamargo@unitropico.edu.co [Grupo de Investigación en Ciencias Básicas, Aplicación e Innovación - CIBAIN, Fundación Universitaria Internacional del Trópico Americano– Unitrópico, Yopal, Casanare (Colombia); Martínez-Pieschacón, D.J. [Departamento de Ciencias Básicas, Universidad Santo Tomás, Tunja, Boyaca (Colombia); Baquero, R. [Departamento de Física, CINVESTAV-IPN, Av. IPN 2508, 07360, México (Mexico)

    2017-04-15

    Highlights: • We present for the first time the effects of Pb doping on structural and electronic properties of Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} (Bi2223) using GGA, compared with LDA results. • We found the Pb concentration for which the Bi–O pockets disappear from the Fermi Surface in the Bi2223 compound using GGA and LDA, respectively. - Abstract: We use Density Functional Theory to study the effects on the crystal structure and the electronic band structure of substituting Pb for Bi in Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}. We further use the Local Density Approximation (LDA) and the Generalized Gradient Approximation (GGA). The Virtual Crystal Approximation (VCA) was used to account for the substitution. We found that GGA reproduces better the lattice parameters although in both cases the internal coordinates were reproduced with some uncertainties. We further looked at the behavior of the so called Bi–O pockets, some electronic states that originate on the Bi–O planes and that appear on the Fermi surface (FS) in contradiction to the experimental evidence. We found that LDA and GGA differ on that subject. With 26% Pb and using LDA, the Bi–O pockets run away from the FS. But when GGA is used, it is needed up to 35% Pb to make the Bi–O pockets disappear from the FS. In the last case, once the Bi–O pockets are removed from the FS, we get a very good agreement with angular resolved photo-emission (ARPES) and nuclear magnetic resonance (NMR) experiments.

  8. Superconducting Bi1.5Pb0.5Sr2Ca2Cu3O(x) ceramics by rapid melt quenching and glass crystallization

    Science.gov (United States)

    Bansal, Narottam P.

    1989-01-01

    A glass of nominal Bi(1.5)Pb(0.5)Sr2Ca2Cu3O(x) composition, prepared by rapid quenching of the melt, showed a glass transition temperature of 383 C, crystallization temperature of 446 C, melting temperature of 855 C, and bulk density of 5.69 g/cu cm in air. The activation energy for crystallization of the glass was estimated to be 292kJ/mol from non-isothermal DSC. On heating in oxygen, the glass showed a slow and continuous weight gain starting at approximately 530 C which reached a plateau at approximately 820 C. The weight gained during heating was retained on cooling to ambient conditions indicating an irreversible oxidation step. The influence of annealing conditions on the formation of various phases in the glass has been investigated. The Bi(2)Sr(2)Ca(0)Cu(1)O(6) phase crystallized out first followed by formation of other phases at higher temperatures. The high-T(sub c) phase, isostructural with Bi(2)Sr(2)Ca(2)Cu(3)O(10) was not detected below 840 C, but its fraction increased with the annealing time at 840 C. A sample annealed at 840 C for 243h in air and furnace cooled showed the highest T(sub c)(R=0) of 107.2K and a narrow transition width, delta T(sub c)(10 to 90 percent), of approximately 2 K. The high T(sub c) phase does not seem to crystallize out directly from the glass but is rather produced at high temperature by reaction between the phases formed at lower temperatures. The kinetics of 110K phase formation was sluggish. It appears that the presence of lead helps in the formation and/or stabilization of the 110 K phase.

  9. 基于PbS量子点和金纳米颗粒的可卡因适体传感器的研究%Preparation of cocaine aptamer sensor based on PbS quantum dots and Au nanoparticles

    Institute of Scientific and Technical Information of China (English)

    李晓飞; 张银烽; 李月婷; 司剑飞; 杨云慧

    2011-01-01

    A novel cocaine aptamer sensor for rapid determination of cocaine in human serum has been developed. The PbS quantum dots were prepared by solvothermal reaction. The aptamer sensor was prepared by immobilizing thiolated complementary DNA onto the surface of glassy carbon electrode modified with PbS quantum dots and chitosan film via the strong bound between PbS and -SH group. Au nanoparticles-labeled cocaine aptamer was used as tracer to detect cocaine. When the aptamer sensor was incubated with cocaine,the specify bound occurred between cocaine and its aptamer,resulting in Au nanoparticles-labeled cocaine aptamer dropping off from the electrode. Then,the reduction current of H2O2 catalyzed by Au NPs decreased,which is proportion to the concentration of cocaine. The electrochemical behavior of aptamer sensor was studied. Other experimental conditions such as Ph, incubation time of cocaine aptamer were studied too. The prepared aptamer sensor offered an amperometric response for cocaine ranging from 1. 0 to 100. 0 nmol · Dm-3 with a detection limit of 0. 3 nmol · Dm-3. The result showed that the aptamer sensor displayed rapid response, high sensitivity, good repeatability and long-term stability.%本文采用水热法合成了硫化铅量子点,将其与壳聚糖混合后修饰在玻碳电极上,利用PbS与巯基之间的强烈的键和作用,直接将所合成的带巯基的与可卡因适体互补的DNA固定到电极上,将金纳米颗粒标记在可卡因适体作为示踪物检测可卡因,研制了一种新型的用于快速测定可卡因的适体传感器.该适体传感器与不同浓度的可卡因培育时,可卡因适体与可卡因发生特异性结合,致使可卡因适体从电极上脱离下来.随着可卡因浓度的增加,脱落的金纳米颗粒的量增加,其催化H2 O2的电流减少,实现对可卡因的检测.考察了适体传感器的电化学特性,同时也研究了测试液pH值、培育时间等实验条件对传感器性能的影

  10. A high temperature piezoelectric ceramic: (1-x)(Bi0.9La0.1)FeO(3-x)PbTiO3 crystalline solutions.

    Science.gov (United States)

    Chen, Jianguo; Qi, Yufa; Shi, Guiyang; Yu, Shengwen; Cheng, Jinrong

    2009-09-01

    (1-x)(Bi(0.9)La(0.1))FeO(3-x)PbTiO(3) (BLF-PT) crystalline solutions for x = 0.35, 0.37, 0.4, 0.43 and 0.45 have been prepared by the solid-state reaction method. The X-ray diffraction analysis shows that BLF-PT has a single perovskite phase with mixed tetragonal and rhombohedral phases between x = 0.4 and 0.43. The Curie temperature of BLF-PT for x = 0.4 attains 460 degrees C, which is about 80 degrees C higher than that of hard Pb(Zr,Ti)O(3) ceramics. The remnant polarization and piezoelectric constant of BLF-PT for x = 0.4 reach 38 microC/cm(2) and 112 pC/N, respectively. The planar coupling factor k(p) of BLF-PT for x = 0.4 remains stable at temperature increases of up to 360 degrees C. The impedance spectroscopy study reveals that the high temperature conduction of BLF-PT may be attributed to the motion of oxygen vacancies within the material. Our results indicate that BLF-PT is a promising candidate for high temperature applications.

  11. Study of dielectric and ferroelectric properties of five-layer Aurivillius oxides: A2Bi4Ti5O18 (A = Ba, Pb and Sr) synthesized by solution combustion route

    Indian Academy of Sciences (India)

    Shivangi Dubey; Rajnish Kurchania

    2015-12-01

    This paper presents the ferroelectric and dielectric properties of five-layer Aurivillius oxides (Ba2Bi4Ti5O18, Pb2Bi4Ti5O18 and Sr2Bi4Ti5O18) prepared by a solution combustion route with glycine as a fuel at low calcination temperature. The phase formation of these materials with pseudo-tetragonal structure was achieved after calcination at 750°C for 3 h; as confirmed by X-ray diffraction studies. Scanning electron microscopy of the sintered ceramics shows that the grains exhibit a plate-like morphology. The ferroelectric to paraelectric transition temperature () for Ba-, Pb- and Sr-based bismuth titanate ceramics was found to be 350, 280 and 260°C, respectively. All three materials show multiple relaxation phenomena and their electrical conductivity was found to be temperature dependent. The Pb2Bi4Ti5O18 ceramic possessed the highest value of activation energy (0.68 eV) and hence shows better ferroelectric properties, as compared to barium and strontium bismuth titanates.

  12. Pull strength evaluation of Sn-Pb solder joints made to Au-Pt-Pd and Au thick film structures on low-temperature co-fired ceramic -final report for the MC4652 crypto-coded switch (W80).

    Energy Technology Data Exchange (ETDEWEB)

    Uribe, Fernando; Vianco, Paul Thomas; Zender, Gary L.

    2006-06-01

    A study was performed that examined the microstructure and mechanical properties of 63Sn-37Pb (wt.%, Sn-Pb) solder joints made to thick film layers on low-temperature co-fired (LTCC) substrates. The thick film layers were combinations of the Dupont{trademark} 4596 (Au-Pt-Pd) conductor and Dupont{trademark} 5742 (Au) conductor, the latter having been deposited between the 4596 layer and LTCC substrate. Single (1x) and triple (3x) thicknesses of the 4596 layer were evaluated. Three footprint sizes were evaluated of the 5742 thick film. The solder joints exhibited excellent solderability of both the copper (Cu) lead and thick film surface. In all test sample configurations, the 5742 thick film prevented side wall cracking of the vias. The pull strengths were in the range of 3.4-4.0 lbs, which were only slightly lower than historical values for alumina (Al{sub 2}O{sub 3}) substrates. General (qualitative) observations: (a) The pull strength was maximized when the total number of thick film layers was between two and three. Fewer that two layers did not develop as strong of a bond at the thick film/LTCC interface; more than three layers and of increased footprint area, developed higher residual stresses at the thick film/LTCC interface and in the underlying LTCC material that weakened the joint. (b) Minimizing the area of the weaker 4596/LTCC interface (e.g., larger 5742 area) improved pull strength. Specific observations: (a) In the presence of vias and the need for the 3x 4596 thick film, the preferred 4596:5742 ratio was 1.0:0.5. (b) For those LTCC components that require the 3x 4596 layer, but do not have vias, it is preferred to refrain from using the 5742 layer. (c) In the absence of vias, the highest strength was realized with a 1x thick 5742 layer, a 1x thick 4596 layer, and a footprint ratio of 1.0:1.0.

  13. Tunnelling spectroscopy of BaFe{sub 2}As{sub 2}/Au/PbIn thin film junctions

    Energy Technology Data Exchange (ETDEWEB)

    Doering, Sebastian; Schmidt, Stefan; Schmidl, Frank; Tympel, Volker; Grosse, Veit; Seidel, Paul [Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena (Germany); Haindl, Silvia; Iida, Kazumasa; Kurth, Fritz; Holzapfel, Bernhard [IFW Dresden, Institut fuer Metallische Werkstoffe, Dresden (Germany)

    2011-07-01

    Tunnelling spectroscopy is an important tool to investigate the properties of iron-based superconductors. In contrast to commonly used point contact Andreev reflection (PCAR) technique, we fabricated hybrid superconductor / normal metal / superconductor (SNS) thin film structures, with tunable barrier thickness and area. For the base electrode we use Ba(Fe{sub 0.9}Co{sub 0.1}){sub 2}As{sub 2} thin films, produced via pulsed laser deposition (PLD). A gold layer was sputtered to form the barrier, while the counter electrode material is the conventional superconductor PbIn with a T{sub c} of 7.2 K. For temperatures below 7.2 K the spectrum shows a subharmonic gap structure (SGS), described by an extended model of Octavio, Tinkham, Blonder and Klapwijk (OTBK), while at higher temperatures the SGS vanishes and an SN-like behaviour can be observed.

  14. 三元金属间化合物La3Cu3Bi4的合成、结构与性能研究%Y3Au3Sb4 type structure La3Cu3Bi4: synthesis, structure and property

    Institute of Scientific and Technical Information of China (English)

    鲁玉明; 范峰; 蔡传兵; 曹世勋; 张金仓

    2008-01-01

    The new intermetallic compound La3Cu3Bi4 was synthesized by arc melting method followed by annealing. The crystal structure refined using the Rietveld method and X-ray powder diffraction data showed to be Y3Au3Sb4 structure type with space group I43D (No.220). The unit cell parameters were a=0.997797(7) nm and V = 0.99341(2) nm3. The structure was characterized by covalent Cu-Bi4 tetrahedron, which formed three-dimensional network by sharing corners and La atoms separated in the space of Cu-Bi4 tetragon. The expansion of La3Cu3Bi4 studied by using low temperature X-ray diffraction showed to be positive expansion and diminished with the temperature rising.

  15. Au, Bi, Co and Nb cross-section measured by quasimonoenergetic neutrons from p + {sup 7}Li reaction in the energy range of 18–36 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Majerle, M., E-mail: majerle@ujf.cas.cz; Bém, P.; Novák, J.; Šimečková, E.; Štefánik, M.

    2016-09-15

    Au, Bi, Co and Nb samples were irradiated several times with quasi-monoenergetic neutrons from p + {sup 7}Li reaction in the energy range of 18–36 MeV. The activities of the samples were measured with the HPGe detector and the reaction rates were calculated. The cross-sections were extracted using the SAND-II method with the reference cross-sections from the EAF-2010 database. The uncertainties of the final results are discussed.

  16. Phase composition and properties of superconducting ceramics based on Bi1.7Pb0.3Sr2Ca2Cu3O y precursors fabricated by melt quenching in a solar furnace

    Science.gov (United States)

    Gulamova, D. D.; Uskenbaev, D. E.; Fantozzi, G.; Chigvinadze, J. G.; Magradze, O. V.

    2009-06-01

    Production of superconducting ceramics based on precursors with rated composition Bi1.7Pb0.3Sr2Ca2Cu3O y is studied. The precursors are synthesized in a solar furnace by melt rapid quenching. The phase composition of the samples is examined by microstructural and X-ray analyses. The temperature dependences of the resistance and magnetic susceptibility are measured. The influence of the composition and crystal structure of the substrate on texturing in the Bi-Sr-Ca-Cu-O system is studied. It is found that the type of quenching plays a significant role, while the type of substrate is of minor significance.

  17. {bold {ital In situ}} measurements of texture and phase development in (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}{endash}Ag tapes

    Energy Technology Data Exchange (ETDEWEB)

    Thurston, T.R. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States); Haldar, P. [Intermagnetics General Corporation, Latham, New York 12110 (United States); Wang, Y.L.; Suenaga, M. [Department of Applied Science, Brookhaven National Laboratory, Upton, New York 11973 (United States); Jisrawi, N.M. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)]|[Department of Physics, Birzeit University, West Bank, Palestine; Wildgruber, U. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    1997-04-01

    Hard x-rays from a synchrotron source were utilized in diffraction experiments performed at elevated temperatures (up to {approximately}870{degree}C) on (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} (Bi-2223) tapes {ital completely} encased in silver. The general behavior of the phase and texture development under typical processing conditions was determined, and the effects that several variations in processing conditions had on the phase and texture development were examined. These results and their implications for improving processing conditions are discussed. {copyright} {ital 1997 Materials Research Society.}

  18. Influence of gold diffusion-doped on phase formation, superconducting and microstructure properties of Bi{sub 1.8}Pb{sub 0.35}Sr{sub 1.9}Ca{sub 2.1}Cu{sub 3}O{sub y} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, O [Department of Physics, Faculty of Arts and Sciences, Kastamonu University, 37600 Kastamonu (Turkey); Akdogan, M; Terzioglu, C [Department of Physics, Faculty of Arts and Sciences, Abant Izzet Baysal University, 14280 Bolu (Turkey); Gencer, A, E-mail: terzioglu_c@ibu.edu.t [Department of Physics, Faculty of Arts and Sciences, Ankara University, 06100 Ankara (Turkey)

    2009-03-01

    We report on low-field magnetic properties of gold diffusion-doped Bi{sub 1.8}Pb{sub 0.35}Sr{sub 1.9}Ca{sub 2.1}Cu{sub 3}O{sub y} superconducting bulk samples by performing ac susceptibility measurements. The undoped samples were prepared by the standard solid-state reaction method. Doping of Bi{sub 1.8}Pb{sub 0.35}Sr{sub 1.9}Ca{sub 2.1}Cu{sub 3}O{sub y} was carried out by means of Au-diffusion during sintering from an evaporated gold film on pellets. To investigate the effect of gold-diffusion and diffusion-annealing duration on transport, magnetic and microstructure properties of the superconducting samples we performed magnetoresistivity, scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. The ac susceptibility as a function of temperature measurements were carried out at different values of the ac magnetic field amplitudes (Hac) in the range between 20A/m and 320 A/m for 211 Hz. The imaginary part of ac susceptibility measurements is used to calculate intergranular critical current density J{sub c}(T{sub p}) using the Bean Model. J{sub c}(T{sub p}) is seen to increase from 60 A cm{sup -2} to 90 A cm{sup -2} with increasing diffusion-annealing time from 10 h to 50 h. The peak temperature, T{sub p}, in the imaginary part of the ac susceptibility is shifted to a lower temperature with decreasing diffusion-annealing duration as well as increasing ac magnetic fields. The force pinning density (alpha{sub j}j (0)) increased with increasing diffusion annealing time. The value of T{sub c} in gold-diffused samples, in comparison with the undoped samples, increased from 100 +- 0.2 K to 104 +- 0.2 K. It was observed that the value of T{sub c-offset} of the gold-doped samples enhanced with further increasing diffusion-annealing duration. XRD patterns and SEM micrographs are used to obtain information about Bi-2223 phase ratio, lattice parameters and grain size of the samples. Gold doping enhanced the formation high-T{sub c} phase and increased the

  19. Texturing of superconducting Bi-Pb-Sr-Ca-Cu-O ceramics by combining the effect of a magnetic field and hot pressing in one direction; Texturation des ceramiques supraconductrices Bi-Pb-Sr-Ca-Cu-O par combinaison des effets du champ magnetique et de la contrainte uniaxiale a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Noudem, J.G.

    1995-10-27

    Superconducting Bi-(Pb)-Sr-Ca-Cu-O (Bi:2223) ceramics have a weak 77 K transport critical current density (Jc) due to porosity and the presence of misaligned platelets. In order to obtain higher critical current densities in these materials, it is necessary to increase their density and induce a preferential crystallographic orientation. We have developed a texturing process using solidification in a magnetic field combined with hot pressing. The experimental set-up provides a uniaxial pressure of 60 MPa and temperature up to 1100 deg C in a magnetic field of 8 T. Magnetic melt texturing (MMT) proved to be very effective in producing bulk oriented samples of polycrystalline Bi:2223 (crystallite c-axis oriented parallel to the field direction). These samples have Jc values of up to 1450 A/cm{sup 2} and a density of 5.1 g/cm{sup 3}. The texturing by hot pressing (HP) gives homogeneous, dense ({approx} 6 g/cm{sup 3}; 95 % of the theoretical limit) ceramics with a Jc of 2500 A/cm{sup 2}. Tapes of Ag/Bi:2223 provided by Alcatel Alsthom were also successful textured using HP. Finally we have demonstrated that the combination of solidification in a magnetic field with hot pressing (MMHPT) improves both the texture and density of the samples. Moreover the samples are very homogeneous and mechanically resistant. The 77 K transport critical current densities have values up to 3800 A/cm{sup 2} and 1100 A/cm{sup 2} along the (ab) and c-axis respectively. We have demonstrated that these samples are of potential use a current limiters. (author) 146 refs.

  20. Quench characteristics of Ag/AuBi2223 HTS-stainless steel stack used for the hybrid current leads of the large hadron collider

    CERN Document Server

    Al-Mosawi, M K; Beduz, C; Yang, Y; Ballarino, A

    2008-01-01

    The quench characteristics of Ag/Au sheathed Bi2223 tapes have been investigated in an adiabatic condition and in a configuration similar to that used in hybrid high temperature superconducting current leads, namely the 13000A leads used for the Large Hadron Collider at CERN. A specialised rig was designed and constructed to provide a carefully controlled environment. The samples were prepared from HTS tape soldered onto a stainless steel substrate with a number of temperature sensors at various positions along the length of tape. One end of the lead (cold end) was maintained at 6K using G-M cryo-cooler whereas the temperature of the other end (warm end) can be varied and maintained at temperatures up to 100K. The thermal runaway currents (quench currents) at various warm end temperatures (in the range of 40-100K) were determined. The temperature evolutions at various locations along the tape were recorded at different top end temperatures and currents. The effect of the stainless steel mechanical reinforceme...

  1. Ferroelectric, piezoelectric, and dielectric properties of BiScO{sub 3}-PbTiO{sub 3}-Pb(Cd{sub 1/3}Nb{sub 2/3})O{sub 3} ternary high temperature piezoelectric ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Tianlong [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Chen Jianguo; Dong Shuxiang [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Wang Chunming [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Yu Yang [Faculty of Physics and Electronic Technology, Hubei University, Wuhan 430062 (China)

    2013-07-14

    (0.95-x)BiScO{sub 3}-xPbTiO{sub 3}-0.05Pb(Cd{sub 1/3}Nb{sub 2/3})O{sub 3} (BS-xPT-PCN) high temperature piezoelectric ceramics near the morphotropic phase boundary (MPB) have been synthesized by traditional solid-state reaction methods. The microstructural morphology, phase structure, and electrical properties of BS-xPT-PCN ceramics were investigated in detail. X-ray diffraction analysis indicated BS-xPT-PCN ceramics have a pure perovskite structure. The coexistence of rhombohedral and tetragonal phases at MPB composition enhanced the polarizability by the coupling between two dynamically equivalent energy states, resulting in the improved piezoelectric and ferroelectric properties at MPB vicinity. The BS-xPT-PCN (x = 0.60) ceramics possess the optimal piezoelectric and ferroelectric properties with d{sub 33} = 505pC/N, k{sub p} = 55.9%, k{sub t} = 36.5%, strain = 0.23% (under the electric field 37.5 kV/cm), and P{sub r} = 39.7 {mu}C/cm{sup 2}. High temperature dielectric behaviors showed diffuse phase transition in BS-xPT-PCN ceramics. The Curie temperature T{sub c} was found to increase from 371 Degree-Sign C to 414 Degree-Sign C with x increasing from 0.58 to 0.62. All these results together with the good thermal stabilities make the BS-xPT-PCN ceramics promising candidates for high temperature piezoelectric applications.

  2. Pathways for the release of polonium from a lead-bismuth spallation target (thermochemical calculation); Verfluechtigungspfade des Poloniums aus einem Pb-Bi-Spallationstarget (Thermochemische Kalkulation)

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, B.; Neuhausen, J

    2004-06-01

    An analysis of literature data for the thermochemical constants of polonium reveals considerable discrepancies in the relations of these data among each other as well as in their expected trends within the chalcogen group. This fact hinders a reliable assessment of possible reaction paths for the release of polonium from a liquid lead-bismuth spallation target. In this work an attempt is made to construct a coherent data set for the thermochemical properties of polonium and some of its compounds that are of particular importance with respect to the behaviour of polonium in a liquid Pb-Bi target. This data set is based on extrapolations using general trends throughout the periodic table and, in particular, within the chalcogen group. Consequently, no high accuracy should be attributed to the derived data set. However, the data set derived in this work is consistent with definitely known experimental data. Furthermore, it complies with the general trends of physicochemical properties within the chalcogen group. Finally, well known relations between thermochemical quantities are fulfilled by the data derived in this work. Thus, given the lack of accurate experimental data it can be regarded as best available data. Thermochemical constants of polonium hydride, lead polonide and polonium dioxide are derived based on extrapolative procedures. Furthermore, the possibility of formation of the gaseous intermetallic molecule BiPo, which has been omitted from discussion up to now, is investigated. From the derived thermochemical data the equilibrium constants of formation, release and dissociation reactions are calculated for different polonium containing species. Furthermore equilibrium constants are determined for the reaction of lead polonide and polonium dioxide with hydrogen, water vapour and the target components lead and bismuth. The most probable release pathways are discussed. From thermochemical evaluations polonium is expected to be released from liquid lead

  3. The Effect of Sintering Temperature on The Rolled Silver-Sheathed Monofilament Bi,Pb-Sr-Ca-Cu-O Superconducting Wire

    Science.gov (United States)

    Hendrik; Sebleku, P.; Siswayanti, B.; Pramono, A. W.

    2017-05-01

    The manufacture of high critical temperature (Tc) Bi, Pb-Sr-Ca-Cu-O (HTS BPSCCO) superconductor wire fabricated by power-in-tube (PIT) is a multi-step process. The main difficulty is that the value of Tc superconductor wire determined by various factors for each step. The objective of this research is to investigate the effect of sintering parameters on the properties of final rolled material. The fabrication process of 1 m rolled-silver sheath monofilament superconductor BPSCCO wire using mechanical deformation process including rolling and drawing has been carried out. The pure silver powders were melted and formed into pure silver (Ag) tube. The tube was 10 mm in diameter with a sheath material: superconductor powders ratio of about 6 : 1. Starting powders, containing the nominal composition of Bi2-Sr2-Cam-1-Cum-Oy, were inserted into the pure silver tube and rolled until it reached a diameter of 4 mm. A typical area reduction ratio of about 5% per step has been proposed to prevent microcracking during the cold-drawing process. The process of rolling of the silver tube was subsequently repeated to obtain three samples and then followed by heat-treated at 820 °C, 840 °C, and 860 °C, respectively. The surface morphology was analyzed by using SEM; the crystal structure was studied by using X-RD, whereas the superconductivity was investigated by using temperature dependence resistivity measurement by using four-point probe technique. SEM images showed the porosity of the cross-sectional surface of the samples. The sample with low heating temperature showed porosity more than the one with high temperature. The value of critical temperature (Tc) of the sample with a dwelling time of heating of 8 hours is 70 K. At above 70 K, it shows the behavior of conductor properties. However, the porosity increased as the heating time increased up to 24 hours. The critical temperature was difficult to be identified due to its porosity. According to XRD results, the Bi-2212

  4. Quasi-2D characteristics in the ac susceptibility response of polycrystalline (Bi,Pb)SrCaCuO/2223 multiphase systems

    Energy Technology Data Exchange (ETDEWEB)

    Mihalache, V. [Department of Low Temperature Physics and Superconductivity, National Institute for Materials Physics, POB MG-7, 077125 Bucharest-Magurele (Romania)], E-mail: vmihal@infim.ro; Cosereanu, L. [METRA, P.O. Box 51-16, 076550 Bucharest (Romania); Miu, L. [Department of Low Temperature Physics and Superconductivity, National Institute for Materials Physics, POB MG-7, 077125 Bucharest-Magurele (Romania)

    2008-01-01

    Fundamental and third harmonic ac susceptibility measurements as a function of temperature T, ac magnetic field, and dc magnetic field have been performed on Bi(Pb)SrCaCuO/2223 bulk samples consisting of both Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+{delta}} (2223) and Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (2212) phases. Since the {chi}{sub 1}{sup ''}(T) peak corresponding to the losses in the weak links between the grains shifts rapidly to lower T and its amplitude is strongly suppressed with increasing the dc magnetic field H{sub dc}, the other peaks related to the losses in the grains become visible. For the samples consisting of single phase 2223, these intragranular peaks are situated near 38 K, 58 K, and 80-88 K (depending on the sample), whereas for the samples consisting of single phase 2212, they are situated near 20 K, 43 K, and 77 K. For H{sub dc} {>=} 1 kOe, the temperature positions of the intragranular peaks are weakly field dependent. This shows that the transition line determined from the loss peaks behaves like the melting line in two-dimensional (2D) systems. Also, as the field increases, the amplitude of the loss peaks can decrease up to their disappearance, suggesting a layer decoupling process. In this way, we show that, above a crossover field of {approx}1 kOe, the vortex lattice in the superconducting grains of polycrystalline samples reproduces the behaviour of the vortex lattice in a quasi-2D object consisting of a set of separated 'thin films' with one-, two-, and three-effective-layer thicknesses. For the samples consisting of both 2223 and 2212 phases, three additional peaks were observed, situated near 28 K, 50 K and 75-80 K (depending on the sample). These peaks were attributed to the regions in which the 2212 and 2223 layers alternate.

  5. Characterization of sol-gel thin films of TiO2-PbO, TiO2-Bi2O3 and TiO2-CeO2 compositions

    Science.gov (United States)

    Aegerter, Michel A.; La Serra, Eliane R.; Martins Rodrigues, Ana C.; Kordas, George; Moore, Glenn A.

    1990-11-01

    Single and multilayer sol-gel thin films of Ti02-PbO, Ti02-Bi203 and Ti02-CeO2 composition were deposited on glasses using the dip coating technique. The precursors included Ti(OPri)4 chemically modified by acetyl acetone and diluted in PriOH and sols of Pb(OAc)2, Bi(NO3)3 5H20 diluted in acetic acid. The Ti02-Ce02 sol was prepared by mixing Ce NH2 (NO3 )6 in ethanol and then adding Ti (O-iso-C3H7 )4. Structure texture and homogeneity of their main constituants was established by XRD, XPS,SIMS and SEM-EDX techniques as a function of heat treatments.

  6. Field induced domain switching as the origin of anomalous lattice strain along non-polar direction in rhombohedral BiScO{sub 3}-PbTiO{sub 3} close to the morphotropic phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Lalitha, K. V.; Ranjan, Rajeev, E-mail: rajeev@materials.iisc.ernt.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Fancher, Chris M.; Jones, Jacob L. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2015-08-03

    The lattice strain and domain switching behavior of xBiScO{sub 3}–(1-x)PbTiO{sub 3} (x = 0.40) was investigated as a function of cyclic field and grain orientation by in situ X-ray diffraction during application of electric fields. The electric field induced 200 lattice strain was measured to be five times larger than the 111 lattice strain in pseudorhombohedral xBiScO{sub 3}–(1-x)PbTiO{sub 3} (x = 0.40). It is shown that the anomalous 200 lattice strain is not an intrinsic phenomenon, but arises primarily due to stress associated with the reorientation of the 111 domains in dense polycrystalline ceramic.

  7. Triangular flow of negative pions emitted in PbAu collisions at √{sNN} = 17.3 GeV

    Science.gov (United States)

    Adamová, D.; Agakichiev, G.; Andronic, A.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielčíková, J.; Braun-Munzinger, P.; Busch, O.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Hering, G.; Holeczek, J.; Kalisky, M.; Karpenko, Iu.; Krobath, G.; Kushpil, V.; Maas, A.; Marín, A.; Milošević, J.; Miśkowiec, D.; Panebrattsev, Y.; Petchenova, O.; Petráček, V.; Radomski, S.; Rak, J.; Ravinovich, I.; Rehak, P.; Sako, H.; Schmitz, W.; Schuchmann, S.; Sedykh, S.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Tsiledakis, G.; Wessels, J. P.; Wienold, T.; Wurm, J. P.; Yurevich, S.; Yurevich, V.

    2017-01-01

    Differential triangular flow, v3 (pT), of negative pions is measured at √{sNN} = 17.3 GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0-30% with a mean centrality of 5.5%. This is the first measurement as a function of transverse momentum of the triangular flow at SPS energies. The pT range extends from about 0.05 GeV/c to more than 2 GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydrodynamic calculation combined with an UrQMD cascade model for the late stages.

  8. Dirac metal to topological metal transition at a structural phase change in Au2Pb and prediction of Z2 topology for the superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Schoop, Leslie M.; Xie, Lilia S.; Chen, Ru; Gibson, Quinn D.; Lapidus, Saul H.; Kimchi, Itamar; Hirschberger, Max; Haldolaarachchige, Neel; Ali, Mazhar N.; Belvin, Carina A.; Liang, Tian; Neaton, Jeffrey B.; Ong, N P; Vishwanath, Ashvin; Cava, R. J.

    2015-06-23

    Three-dimensionalDirac semimetals (DSMs) arematerials that have masslessDirac electrons and exhibit exotic physical properties. It has been suggested that structurally distorting a DSM can create a topological insulator but this has not yet been experimentally verified. Furthermore, Majorana fermions have been theoretically proposed to exist inmaterials that exhibit both superconductivity and topological surface states. Herewe showthat the cubic Laves phase Au2Pb has a bulk Dirac cone that is predicted to gap on cooling through a structural phase transition at 100 K. The low temperature phase can be assigned a Z(2) = -1 topological index, and this phase becomes superconducting below 1.2 K. These characteristics make Au2Pb a unique platform for studying the transition between bulk Dirac electrons and topological surface states as well as studying the interaction of superconductivity with topological surface states, combining many different properties of emergent materials-superconductivity, bulk Dirac electrons, and a topologically nontrivial Z(2) invariant.

  9. Procesamiento y caracterización microestructural del material cerámico ferroeléctrico PbBi4Ti4Nb0,06O15,15

    Directory of Open Access Journals (Sweden)

    Carlos Arciniegas

    2008-11-01

    Full Text Available En la búsqueda de materiales que mantengan buenas propiedades piezoeléctricas a temperaturas mayores que 150 ºC, se ha puesto atención a los compuestos ferroeléctricos con estructura laminar de bismuto. En el presente trabajo, se ha procesado en forma cerámica un compuesto de dicha familia, el PbBi4Ti4Nb0.06O15,15, por el método convencional de mezcla de óxidos en estado sólido a partir del compuesto PbBi4Ti4O15 (PBIT ya formado y de óxido de niobio. Se ha estudiado la estructura cristalina y la microestructura del material sinterizado a diferentes temperaturas. La caracterización estructural muestra la formación de una fase mayoritaria con simetría ortorrómbica, la del PBIT dopado con niobio. La microestructura está formada por granos tipo placa con relación de aspecto menor que la de los granos del compuesto PBIT. / Searching for materials with good piezoelectric properties above 150 ºC, special attention has been given to the family of ferroelectrics compounds of bismuth with laminar structure. We report the processing of a ceramic form of a member of such family, namely the PbBi4Ti4Nb0.06O15,15. Following the conventional method, we mixed PbBi4Ti4O15 (PBIT and niobium oxide. We have studied the crystal structure and the microstructure of the sinterized material at several temperatures. The structural characterization suggest that the PBIT doped with niobium is the only phase present with orthorrombic simetry. The microstructure shows plaque - like grains smaller than the ones in PBIT.

  10. Absence of morphotropic phase boundary effects in BiFeO3-PbTiO3 thin films grown via a chemical multilayer deposition method

    Science.gov (United States)

    Gupta, Shashaank; Bhattacharjee, Shuvrajyoti; Pandey, Dhananjai; Bansal, Vipul; Bhargava, Suresh K.; Peng, Ju Lin; Garg, Ashish

    2011-07-01

    We report an unusual behavior observed in (BiFeO3)1- x -(PbTiO3) x (BF- xPT) thin films prepared using a multilayer chemical solution deposition method. Films of different compositions were grown by depositing several bilayers of BF and PT precursors of varying BF and PT layer thicknesses followed by heat treatment in air. X-ray diffraction showed that samples of all compositions show mixing of two compounds resulting in a single-phase mixture, also confirmed by transmission electron microscopy. In contrast to bulk compositions, samples show a monoclinic (MA-type) structure suggesting disappearance of the morphotropic phase boundary (MPB) at x=0.30 as observed in the bulk. This is accompanied by the lack of any enhancement of the remanent polarization at the MPB, as shown by the ferroelectric measurements. Magnetic measurements showed an increase in the magnetization of the samples with increasing BF content. Significant magnetization in the samples indicates melting of spin spirals in the BF- xPT films, arising from a random distribution of iron atoms. Absence of Fe2+ ions was corroborated by X-ray photoelectron spectroscopy measurements. The results illustrate that thin film processing methodology significantly changes the structural evolution, in contrast to predictions from the equilibrium phase diagram, besides modifying the functional characteristics of the BP- xPT system dramatically.

  11. The influence of fast neutron irradiation on the intra- and intergrain properties of the polycrystalline BiPbSrCaCuO system

    Science.gov (United States)

    Wiśniewski, A.; Baran, M.; Kozioł, Z.; Przysłupski, P.; Piechota, J.; Puźniak, R.; Pajaçzkowska, A.; Pȩkała, M.; Pytel, B.; Pytel, K.

    1990-09-01

    The influence of irradiation by fast neutrons with fluences from 3.3 x 10 16n/ cm2 up to 3 x 10 18n/ cm2 on the physical properties of polycrystalline Bi0.7Pb0.3SrCaCu1.8Ox was examined. Studies of DC magnetization, AC susceptibility, transport and thermoelectric power were performed. The irradiation caused a decrease of Tc, determined from the onset of diamagnetism, by as much as 31 K for a fluence of 3 x 10 18n/ cm2. A strong influence of neutron irradiation on both intra- and intergranular properties was observed. The defects within the superconducting grains created by neutrons caused an increase of the pinning forces which enhanced the critical magnetization current. A gradual decoupling of Josephson weak links with increasing neutron fluence was observed in transport and low field magnetization measurements. From the AC susceptibility measurements the irreversibility lines between the flux-creep and flux-flow regions were determined. An increase of the absolute values of thermoelectric power with rising fluence was noticed.

  12. Behavior of steels in flowing liquid PbBi eutectic alloy at 420-600 deg. C after 4000-7200 h

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, G. [Forschungszentrum Karlsruhe GmbH, Institute for Pulsed Power and Microwave Technology, P.O. Box 3640, D-76021 Karlsruhe (Germany); Heinzel, A. [Forschungszentrum Karlsruhe GmbH, Institute for Pulsed Power and Microwave Technology, P.O. Box 3640, D-76021 Karlsruhe (Germany)]. E-mail: annette.heinzel@ihm.fzk.de; Konys, J. [Forschungszentrum Karlsruhe GmbH, Institute for Pulsed Power and Microwave Technology, P.O. Box 3640, D-76021 Karlsruhe (Germany); Schumacher, G. [Forschungszentrum Karlsruhe GmbH, Institute for Pulsed Power and Microwave Technology, P.O. Box 3640, D-76021 Karlsruhe (Germany); Weisenburger, A. [Forschungszentrum Karlsruhe GmbH, Institute for Pulsed Power and Microwave Technology, P.O. Box 3640, D-76021 Karlsruhe (Germany); Zimmermann, F. [Forschungszentrum Karlsruhe GmbH, Institute for Pulsed Power and Microwave Technology, P.O. Box 3640, D-76021 Karlsruhe (Germany); Engelko, V. [Efremov Institute of Electrophysical Apparatus, 189631 St. Petersburg (Russian Federation); Rusanov, A. [IPPE, Bondarenko Square 1, 249020 Obninsk, Kaluga Region (Russian Federation); Markov, V. [CRISM ' PROMETEY' , 193015 St. Petersburg (Russian Federation)

    2004-11-01

    This paper presents the results of steel exposure up to 7200 h in flowing LBE at elevated temperatures and is a follow-up paper of that with results of an exposure of up to 2000 h. The examined AISI 316 L, 1.4970 austenitic and MANET 10Cr martensitic steels are suitable as a structural material in LBE (liquid eutectic Pb{sub 45}Bi{sub 55}) up to 550 deg. C, if 10{sup -6} wt% of oxygen is dissolved in the LBE. The martensitic steel develops a thick magnetite and spinel layer while the austenites have thin spinel surface layers at 420 deg. C and thick oxide scales like the martensitic steel at 550 deg. C. The oxide scales protect the steels from dissolution attack by LBE during the whole test period of 7200 h. Oxide scales that spall off are replaced by new protective ones. At 600 deg. C severe attack occurs already after 2000 and 4000 h of exposure. Steels with 8-15 wt% Al alloyed into the surface suffer no corrosion attack at all experimental temperatures and exposure times.

  13. Excitation functions of residual nuclei production from 40–2600 MeV proton-irradiated 206,207,208,natPb and 209Bi

    Indian Academy of Sciences (India)

    Yu E Titarenko; V F Batyaev; V M Zhivun; V O Kudryashov; K A Lipatov; A V Ignatyuk; S G Mashnik

    2007-02-01

    The work is aimed at experimental determination of the independent and cumulative yields of radioactive residual nuclei produced in intermediate-energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb) and 209Bi. 5972 radioactive product nuclide yields have been measured in 55 thin targets induced by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6 and 2.6 GeV protons extracted from the ITEP U-10 proton synchrotron. The measured data have been compared with data obtained at other laboratories as well as with theoretical simulations by seven codes. We found that the predictive power of the tested codes is different but is satisfactory for most of the nuclides in the spallation region, though none of the codes agree well with the data in the whole mass region of product nuclides and all should be improved further.

  14. Effect of substitution of Ce on superconducting properties of Bi1.7Pb0.3Sr2Ca2-CeCu3O10+ system

    Indian Academy of Sciences (India)

    R R Kothawale; B N Dole; S S Shah

    2002-05-01

    We have investigated the superconducting properties of the Bi1.7Pb0.3Sr2Ca2-CeCu3O10+ system with = 0.00, 0.02, 0.04, 0.08 and 0.1 by X-ray diffraction and magnetic susceptibility. The substitution of Ce for Ca has been found to drastically change the superconducting properties of the system. X-ray diffraction studies on these compounds indicate decrease in the -parameter with increased substitution of Ce at Ca site and volume fraction of high c(2 : 2 : 2 : 3) phase decreases and low c phase increases. The magnetic susceptibility of this compound shows that the diamagnetic on set superconducting transition temperature (onset) varies from 109 K to 51 K for =0.00, 0.02, 0.04, 0.08 and 0.1. These results suggest the possible existence of Ce in a tetravalent state rather than a trivalent state in this system; that is, Ca2+ → Ce4+ replacement changes the hole carrier concentration. Hole filling is the cause of lowering c of the system.

  15. Preparation and Properties of High-T(sub c) Bi-Pb-Sr-Ca-Cu-O Thick Film Superconductors on YSZ Substrates

    Science.gov (United States)

    Hooker, Matthew W.

    1996-01-01

    An evaluation of four firing profiles was performed to determine the optimum processing conditions for producing high-T(sub c) Bi-Pb-Sr-Ca-Cu-O thick films on yttria-stabilized zirconia substrates. Using these four profiles, the effects of sintering temperatures of 830-850 C and soak times of 0.5 to 12 hours were examined. In this study, T-c, zero values of 100 K were obtained using a firing profile in which the films were sintered for 1.5 to 2 hours at 840 to 845 C and then quenched to room temperature. X-ray diffraction analyses of these specimens confirmed the presence of the high-T(sub c) phase. Films which were similarly fired and furnace cooled from the peak processing temperature exhibited a two-step superconductive transition to zero resistance, with T-c,zero values ranging from 85 to 92 K. The other firing profiles evaluated in this investigation yielded specimens which either exhibited critical transition temperatures below 90 K or did not exhibit a superconductive transition above 77 K.

  16. Percolation effect in thick film superconductors: Using a Bi(Pb)SrCaCuO based paste to prepare a superconducting planar transformer

    Science.gov (United States)

    Sali, Robert; Harsanyi, Gabor

    1995-01-01

    A thick film superconductor paste has been developed to study the properties of granulated superconductor materials, to observe the percolation effect and to confirm the theory of the conducting mechanism in the superconducting thick films. This paste was also applied to make a superconducting planar transformer. Due to the T(sub c) and advantageous current density properties the base of the past was chosen to be of Bi(Pb)SrCaCu) system. For contacts a conventional Ag/Pt paste was used. The critical temperature of the samples were between 110 K and 115 K depending on the printed layer thickness. The critical current density -at the boiling temperature of the liquid He- was between 200 - 300 A/sq cm. The R(T) and V(I) functions were measured with different parameters. The results of the measurements have confirmed the theory of conducting mechanism in the material. The percolation structure model has been built and described. As an application, a superconducting planar thick film transformer was planned and produced. Ten windings of the transformer were printed on one side of the alumina substrate and one winding was printed on the other side. The coupling between the two sides was possible through the substrate. The samples did not need special drying and firing parameters. After the preparation, the properties of the transformer were measured. The efficiency ans the losses were determined. Finally, some fundamental advantages and problems of the process were discussed.

  17. Radon and progeny ({sup 214}Pb and {sup 214}Bi) in urban water-supply systems of Sao Paulo State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, Daniel Marcos [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Av. 24-A, No. 1515, C.P. 178, CEP 13506-900 Rio Claro, Sao Paulo (Brazil)], E-mail: danielbonotto@yahoo.com.br; Padron-Armada, Priscilla Cardoso [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Av. 24-A, No. 1515, C.P. 178, CEP 13506-900 Rio Claro, Sao Paulo (Brazil)

    2008-10-15

    Many water-supply systems in South America utilize the waters of the Guarani aquifer at least as part of their networks. However, there is little present knowledge in Brazil of the factors affecting Rn presence in the water supplied for end-users, despite the economic importance of Guarani aquifer. {sup 222}Rn analyzes of 162 water samples were performed at 8 municipalities in Sao Paulo State, Brazil, with the aim of investigating the major factors affecting its presence in solution. The {sup 222}Rn activity concentration ranged from 0.04 up to 204.9 Bq/L, with three samples exceeding the World Health Organization maximum limit of 100 Bq/L. Aeration was confirmed as the most important factor for Rn release, as expected due to its gaseous nature. Accumulation in pipes and stratification in the water column were other significant factors explaining the data obtained in some circumstances. The Rn daughters {sup 214}Pb and {sup 214}Bi were also determined in a set of selected samples and their presence was directly related to the occurrence of Rn dissolved in water.

  18. 熔化处理温度对银包套带材中(Bi,Pb)-2223相熔化分解-再形成行为的影响%Effect of Melting Temperature on the Decomposition and Reformation Behavior of(Bi,Pb)-2223 Core in the Ag-sheathed Tape

    Institute of Scientific and Technical Information of China (English)

    李敬勇; 郑会玲; 李成山; 卢亚锋; 周廉

    2007-01-01

    The effect of melting temperature on the decomposition and reformation of(Bi,Pb)-2223(abbreviated as 2223)phase in a Ag-sheathed mono-filamentary tape under 7.5%O2 flow balanced with argon have been investigated by means of ex-situ X-ray diffraction(XRD)and scanning electron microscopy equipped with energy dispersive spectroscopy(SEM/EDS).It is shown that a partial melting at an appropriate temperature range,which produce a 2212-like melt and alkaline earth cuprates(AEC),especially(Sr,Ca)14Cu24O41(14:24-AEC)and(Ca,Sr)2CuO3(2:1-AEC),as the main decomposition products of 2223,is very important for this high-Tc phase reformation.The melt composition evolved from that between 2223 and 2212 stoichiometries towards 2212,and then to 2201 stoichiometry as melting temperature increasing.It is demonstrated that 2223 could be easily formed from a 2212-like melt but Bi-2212 could be crystallized from a near 2201-like melt.The recrystallization of 2223 from the melt at an excessively high temperature might experience two different routes during the slow-cooling,one is that 2223 reformed directly from the melt and the other iS that 2223 iS transferred from the Bi-2212.%应用X射线衍射(XRD)和扫描电镜/能谱分析(SEM/EDS)研究了7.5%O2-Ar条件下,熔化处理温度对银包套单芯带材芯部(Bi,Pb)-2223(简称2223)相的分解及再形成行为的影响.结果表明,适当温度下,2223相部分熔化生成一种类似于(Bi,Pb)-2212的液相和碱土铜酸盐(AEC),主要是(Sr,Ca)14CU24O41(14:24-AEC)和(Ca,Sr)2CuO3(2:1-AEC),对于这一高温超导相的可逆再形成至关重要.随着熔化处理温度的升高,2223相熔化分解生成的液相的成分经历了从介于2223和2212计量比之间向2212,并进一步向2201计量比的演变过程.2223相易于从类似于2212的液相中析出,而从接近2201计量比的液相中更易于生成2212相.2223相从过度熔化生成的液相中再形成经历了两个途径:一是直接从液相中析出,二是

  19. Structural properties of superconducting Bi-2223/Ag tapes

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalck Andersen, L.

    2001-05-01

    The structural properties of silver clad high-T{sub c} superconducting ceramic tapes of (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Bi-2223) have been investigated by means of synchrotron X-ray diffraction (including the 3DXRD microscope setup), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDS). By synchrotron X-ray diffraction in situ studies of the phase development during the transformation of (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 1}Cu{sub 2}O{sub x} (Bi-2212) into Bi-2223, the stoichiometry changes and the texture have been performed during annealing in 8% O{sub 2} and in air. Furthermore, an annealing with two high temperature cycles has been performed to study the equilibrium phenomena. During heating (Ca,Sr){sub 2}PbO{sub 4} decomposes at temperatures between 700 deg. C and 840 deg.C. Simultaneously, the Bi-2212 lattice contracts, indicating an incorporation of Pb. Moreover, the grain mis-alignment decreases significantly. In air we have observed that Bi-2212 partly dissociates into (Ca,Sr){sub 2}CuO{sub 3} and a liquid at temperatures above 812 deg. C. At the annealing temperature Bi-2212 and (Ca,Sr){sub 2}CuO{sub 3} react with the liquid to form Bi-2223. The transformation mechanism is discussed. During cooling below {approx}750 deg.C (Ca,Sr){sub 2}CuO{sub 3} and the liquid mainly transform into Bi-2201. Below {approx}780 deg. C Bi-2223 decomposes to 3221. In addition, a two-step cooling experiment and a decomposition study have been performed in 8% O{sub 2}. By TEM the grain and colony size in the c-axis direction, the angles of c-axis tilt grain boundaries and the intergrowth content are investigated. A fully processed tape has on average 50% thicker grains than a tape after the 1st annealing. The angles of c-axis tilt grain boundaries are on average 14 deg. and 26 deg. for the fully processed tape and the tape after the 1st annealing, respectively. The intergrowth content (15%) and

  20. Pb solubility of the high-temperature superconducting phase Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+d}

    Energy Technology Data Exchange (ETDEWEB)

    Kaesche, S.; Majewski, P.; Aldinger, F. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany)] [and others

    1994-12-31

    For the nominal composition of Bi{sub 2.27x}Pb{sub x}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+d} the lead content was varied from x=0.05 to 0.45. The compositions were examined between 830{degrees}C and 890{degrees}C which is supposed to be the temperature range over which the so-called 2223 phase (Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+d}) is stable. Only compositions between x=0.18 to 0.36 could be synthesized in a single phase state. For x>0.36 a lead containing phase with a stoichiometry of Pb{sub 4}(Sr,Ca){sub 5}CuO{sub d} is formed, for x<0.18 mainly Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+d} and cuprates are the equilibrium phases. The temperature range for the 2223 phase was found to be 830{degrees}C to 890{degrees}C but the 2223 phase has extremely varying cation ratios over this temperature range. Former single phase 2223 samples turn to multi phase samples when annealed at slightly higher or lower temperatures. A decrease in the Pb solubility with increasing temperature was found for the 2223 phase.

  1. The effect of Al2O3 nanopowder addition on the phase formation and the superconducting properties of Bi1.6Pb0.4Sr1.9Ca2.1Cu3O10-y

    Directory of Open Access Journals (Sweden)

    A Aftabi

    2009-08-01

    Full Text Available   In this work Bi1.6Pb0.4Sr1.9Ca2.1Cu3O10-y superconducting system (Bi2223 has been prepared by solid state reaction and the effect of nanoalumina additive on the phase formation and supercoducting properties have been investigated. XRD investigations show that addition of 0.2 wt% of nanoalumina on the superconducting system improved Bi-2223 phase formation . The results show that Jc increases from 36 A/cm2 for the nanoalumina free sample to 107 A/cm2 for the sample with 0.5 wt% nanoalumina.On the other hand results show that the transition temperature (Tc of all samples is around 108 K and addition of nanoalumina has not affected Tc significantly .

  2. One-step electrochemical preparation of the ternary (Bi{sub x}Sb{sub 1-x}){sub 2}Te{sub 3} thin films on Au(1 1 1): Composition-dependent growth and characterization studies

    Energy Technology Data Exchange (ETDEWEB)

    Erdogan, Ibrahim Y. [Bingoel University, Sciences and Arts Faculty, Department of Chemistry, 12000, Bingoel (Turkey); Demir, Umit, E-mail: udemir@atauni.edu.t [Atatuerk University, Sciences Faculty, Department of Chemistry, 25240, Erzurum (Turkey)

    2010-09-01

    This study reports on the synthesis of ternary semiconductor (Bi{sub x}Sb{sub 1-x}){sub 2}Te{sub 3} thin films on Au(1 1 1) using a practical electrochemical method, based on the simultaneous underpotential deposition (UPD) of Bi, Sb and Te from the same solution containing Bi{sup 3+}, SbO{sup +}, and HTeO{sub 2}{sup +} at a constant potential. The thin films are characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and reflection absorption-FTIR (RA-FTIR) to determine structural, morphological, compositional and optic properties. The ternary thin films of (Bi{sub x}Sb{sub 1-x}){sub 2}Te{sub 3} with various compositions (0.0 {<=} x {<=} 1.0) are highly crystalline and have a kinetically preferred orientation at (0 1 5) for hexagonal crystal structure. AFM images show uniform morphology with hexagonal-shaped crystals deposited over the entire gold substrate. The structure and composition analyses reveal that the thin films are pure phase with corresponding atomic ratios. The optical studies show that the band gap of (Bi{sub x}Sb{sub 1-x}){sub 2}Te{sub 3} thin films could be tuned from 0.17 eV to 0.29 eV as a function of composition.

  3. Study and characterization of electrical properties of the SrBi{sub 4}Ti{sub 4}O{sub 15} (SBTi) doped with PbO{sub 2}; Caracterizacao e estudo de propriedades eletricas do SrBi{sub 4}Ti{sub 4}O{sub 15} (SBTi) dopado com PbO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Junior, C.A.; Sombra, A.S.B., E-mail: cauby@fisica.ufc.b [Universidade Federal do Ceara (LOCEM/UFC), Fortaleza, CE (Brazil). Dept. de Fisica. Lab. de Telecomunicacoes e Ciencia e Engenharia dos Materiais; Silva Filho, J.M.; Sales, J.C. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia de Teleinformatica; Silva, M.A.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica

    2009-07-01

    SrBi{sub 4}Ti{sub 4}O{sub 15} (SBTi) ceramic, a perovskite with cation deficient system as in A{sub 5}BB{sub 4}O{sub 15} was prepared by high-temperature solid-state reaction method using high purity ingredients (carbonates and oxides): oxide of bismuth (Bi{sub 2}O{sub 4}), Oxide of Titan (Ti{sub 2}O{sub 4}), and Strontium Carbonate (SrCO{sub 3}), in required stoichiometry. The previous powders were mixed and ball-milled thoroughly in an agate mortar for 2h and calcined in air atmosphere at 850 deg C for 3h. The mixing and calcinations were repeated several times. Then the calcination was finally completed. The compounds were checked by X-ray diffraction (XRD) techniques. SBTi was doped, in following proportions: 2%, 5%, 10% and 15% of PbO{sub 2} mass and sintered as pellets that were made under a uniaxial pressure using a press and in powder at 950 deg C for 3h. Polyvinyl alcohol (PVA) was used as a binder to reduce the brittleness of the pellets. Finally, the studies of electric and dielectric properties were accomplished by using these pellets. (author)

  4. Effect of Pb substitution on the thermo electrical properties of textured Bi{sub 2}Ca{sub 2}Co{sub 1}.7O{sub y} ceramics prepared by a polymer solution method

    Energy Technology Data Exchange (ETDEWEB)

    Rasekh, S. H.; Madre, M. A.; Diez, J. C.; Guilmeau, E.; Marinel, S.; Sotelo, A.

    2010-07-01

    Thermo electrical properties of cobaltate ceramics can be tuned up by choosing the adequate synthetic method, cation substitution and subsequent grain orientation. This can be performed preparing the ceramics by a polymer solution method, using Pb partially substituting Bi, and texturing by directionally growing from the melt. In this work, Bi{sub 2}-xPb{sub x}Ca{sub 2}Co{sub 1}.7O{sub y} (x 0.0, 0.2, 0.4 and 0.6) ceramics, prepared by a polymer solution method, have been directionally grown, with the Laser Floating Zone (LFZ) technique, at 30 mm/h. In all the cases, the microstructure shows alternated layers with small CoO inclusions. It has been found a very important decrease on the resistivity and, at the same time, on the thermopower. However, the power factor values are improved with Pb addition, reaching power factor values, for samples with 0.4 Pb substitution, as high as two times the values obtained for undoped ones. (Author) 30 refs.

  5. L{sub i} (i=1,2,3) subshell X-ray production cross-sections and fluorescence yields for Ir, Pt, Pb and Bi

    Energy Technology Data Exchange (ETDEWEB)

    Singh, P.; Sharma, M.; Shahi, J.S.; Mehta, D.; Singh, N. E-mail: nsingh@pu.ac.in

    2003-09-01

    The L{sub i} (i=1,2,3) subshell X-ray production (XRP) cross-sections were measured for {sub 77}Ir, {sub 78}Pt, {sub 82}Pb and {sub 83}Bi following direct ionization in the L{sub i} (i=1,2,3) subshells by the 59.54 keV {gamma}-rays and the L{sub 3} subshell by the Br/Rb/Sr/Y K X-rays. The photon sources consisting of an {sup 241}Am source in (i) the direct excitation mode and (ii) the secondary excitation mode together with the KBr/RbNO{sub 3}/SrCO{sub 3} /Y secondary exciter and an Si(Li) detector were used. The L{sub i} (i=1,2,3) subshell fluorescence yields ({omega}{sub i}) for these elements were deduced using the measured XRP cross-sections and the L{sub i} subshell photoionization cross-sections based on the Hartree-Fock-Slater model. The measured {omega}{sub 1} values are found to be higher upto 50% than those based on the relativistic Dirac-Hartree-Slater (RDHS) calculations, while the {omega}{sub 2} and {omega}{sub 3} values exhibit good agreement. The predicted jump in the RDHS based {omega}{sub 1} values from {sub 77}Ir to {sub 78}Pt due to onset of intense L{sub 1}-L{sub 3}M{sub 4} CK transition is not observed.

  6. Evaluation of matrix effect on the determination of rare earth elements and As, Bi, Cd, Pb, Se and In in honey and pollen of native Brazilian bees (Tetragonisca angustula - Jataí) by Q-ICP-MS.

    Science.gov (United States)

    de Oliveira, Fernanda Ataide; de Abreu, Adriana Trópia; de Oliveira Nascimento, Nathália; Froes-Silva, Roberta Eliane Santos; Antonini, Yasmine; Nalini, Hermínio Arias; de Lena, Jorge Carvalho

    2017-01-01

    Bees are considered the main pollinators in natural and agricultural environments. Chemical elements from honey and pollen have been used for monitoring the environment, the health of bees and the quality of their products. Nevertheless, there are not many studies on honey and pollen of native Brazilian bees. The goal of this work was to determine important chemical elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Lu and Yb) along with As, Bi, Cd, Pb, Se and In, in honey and pollen of native Brazilian bees, assessing analytical interferences from the matrix. A proposed analytical method was developed for these elements by quadrupole ICP-MS. Matrix effect was verified in honey matrix in the quantification of As, Bi and Dy; and in pollen matrix for Bi, Cd, Ce, Gd, La, Pb and Sc. The quality of the method was considered satisfactory taking into consideration the recovery rate of each element in the spiked solutions: honey matrix (91.6-103.9%) and pollen matrix (94.1-115.6%). The quantification limits of the method ranged between 0.00041 and 10.3μgL(-1) for honey and 0.00041-0.095μgL(-1) for pollen. The results demonstrate that the method is accurate, precise and suitable. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Anomalies of AC susceptibility losses in the doped [Bi(Pb)]{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Mihalache, V [National Institute for Materials Physics, Bucharest-Magurele, PO Box MG-7, R-76900 (Romania); Aldica, G [National Institute for Materials Physics, Bucharest-Magurele, PO Box MG-7, R-76900 (Romania); Badica, P [National Institute for Materials Physics, Bucharest-Magurele, PO Box MG-7, R-76900 (Romania); Crisan, A [National Institute for Materials Physics, Bucharest-Magurele, PO Box MG-7, R-76900 (Romania)

    2004-04-01

    AC susceptibility measurements have been performed on Bi{sub 1.7}Pb{sub 0.4}Sr{sub 1.5}Ca{sub 2.5}Cu{sub 3.6}O{sub x} (Bi-2223) samples doped with different Li-based compounds and prepared by the solid-state method. As-prepared samples and/or samples annealed in oxygen or argon, ground or unground, have been investigated in detail in order to understand the occurrence, nature and evolution of the anomalous peaks observed in {chi}''(T) curves versus the measuring parameters; we have detected up to four peaks instead of the usual two peaks observed in the non-doped samples. It was found that intrinsic physical-chemical properties, such as the melting temperature of the doping compound, are no less important for the final properties of the superconductor than their insertion properties into the crystal lattice of Bi-2223. Doping compounds with melting temperatures below or close to the phase formation temperature of the Bi-2223 phase can act as flux, changing the growth conditions. Intensification of some processes against others (e.g. decomposition-recovery of the Bi-2223 phase, solubilization-precipitation of the secondary phases, changes in the properties of the liquid phase, etc) can lead to the formation of the Bi-2223 phase with different properties than for the non-doped superconductor. Generally, when using flux-type doping compounds, anomalous AC losses peaks are detected and the intra-granular critical current density is enhanced.

  8. Effect of pelletization pressure on structural properties and critical current hysteresis of ceramic superconducting Bi sub 1 sub . sub 7 Pb sub 0 sub . sub 3 Sr sub 2 Ca sub 2 Cu sub 3 O sub y

    CERN Document Server

    Tepe, M; Abukay, D

    2003-01-01

    The effect of pelletization pressures on structural properties and critical current hysteresis of Bi sub 1 sub . sub 7 Pb sub 0 sub . sub 3 Sr sub 2 Ca sub 2 Cu sub 3 O sub y samples was investigated. The samples used in this study were prepared by classical solid-state reaction at the pressures from 100 up to 500 MPa. The obtained samples were characterized by resistance vs. temperature, (R-T), critical current density vs. applied magnetic field, (J sub c -H), material density vs. pressure, (rho-P), XRD, SEM, and EDAX. The results of this study showed that the quality of electrical and structural properties of Bi-2223 bulk superconductors strongly depends on the pelletization pressure. Pressing of bulk samples at 400 MPa produces textured grain alignment and associates microstructural modifications in order to enhance flux pinning and thus increases current carrying capacities. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  9. Origin of positive out-of-plane magnetoconductivity in overdoped Bi1.6Pb0.4Sr2CaCu1.96Fe0.04O8 +δ

    Science.gov (United States)

    Watanabe, Takao; Usui, Tomohiro; Adachi, Shintaro; Teramoto, Yuki; Dobroka, Mihaly M.; Kakeya, Itsuhiro; Kondo, Akihiro; Kindo, Koichi; Kimura, Shojiro

    2016-11-01

    To elucidate the pseudogap phase diagram including the overdoped state of high transition temperature (high-Tc) cuprates, we must understand the origin of the positive out-of-plane magnetoconductivity observed in these compounds. For this purpose, the out-of-plane resistivity ρc(T ,H ) of an overdoped Bi1.6Pb0.4Sr2CaCu1.96Fe0.04O8 +δ (Bi-2212) single crystal is measured under pulsed magnetic fields up to 60 T. We show that the superconducting density-of-states depletion effect, in addition to the pseudogap effect, clearly appears below the superconducting fluctuation regime, and the contribution becomes dominant in the superconducting state.

  10. Raman studies in off-stoichiometric superconducting compounds of the Type Bi{sub 2-x}Pb{sub y}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub {delta}}

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, C.M.; Valdes, E.D.; Malagon, G.P.; Puente, G.C.; Lopez, J.O. [Instituto Politecnico Nacional (Mexico); Falcony, C.; Gallardo, A.C. [Centro de Investigacion y Estudios Avanzados (Mexico)

    1995-02-01

    Raman measurements performed on superconducting ceramic samples of the type Bi{sub 2-x}Pb{sub y}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub {delta}}, with y = 0.3, 0.6, 0.9 and x = 0.1, 0.2, are reported. All Raman phonons with symmetry A{sub 1g} have been observed. Phonon identification has been carried out using previous reported studies of the Bi{sub 2}Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub 2n+y} system, for n = 1, 2, 3. A description of the detected Raman active modes in all samples is given, and the study of these modes in terms of the relative amount of lead-to-bismuth content and thermal treatment is also presented.

  11. The influence of V{sub 2}O{sub 5} on dielectric properties of PbO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Padmanabham, A [G.V.V.R. Institute of Technology, Vempa Road, Bhimavaram-534 207, A.P. (India); Gandhi, Y; Rao, M V Ramachandra; Appaji, D V M [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid-521 201, A.P. (India); Rao, M V N Padma, E-mail: apnabham@gmail.com [Department of Physiscs, P.B. Siddhartha Degree College, Vijayawada, A.P. (India)

    2009-07-15

    The influence of V{sub 2}O{sub 5} (ranging from 0 to 1.0 mol %) on the structural aspects of PbO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3} glass system, from a systematic study of dielectric properties (dielectric constant {epsilon}, loss tan {delta} and a.c. conductivity {sigma}ac, over a wide range of frequency and temperature) and IR spectra has been investigated. The dielectric constant {epsilon}'and loss at room temperature (30 deg. C) and at 100 kHz of pure PbO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3} glasses are measured to be 9.61 and 0.0013 respectively. These values are found to increase with the decrease in frequency. The dielectric constant and loss have been observed with increase in the concentration of V{sub 2}O{sub 5} (up to 1.0 mol %). In the IR spectra of PbO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3}: V{sub 2}O{sub 5} glasses, the intensity of the band due to BO{sub 3} structural units is observed to grow at the expense of more ordered BO{sub 4} structural units with the increase in the concentration of V{sub 2}O{sub 5} up to 1.0 mol %. The analysis of these results indicated that as the concentration of V{sub 2}O{sub 5} is raised up to 1.0 mol %, there is a growing degree of disorder in the glass network.

  12. Measurement of the L/K electron capture ratio of the {sup 207}Bi decay to the 1633 keV level of {sup 207}Pb with a BGO scintillating bolometer

    Energy Technology Data Exchange (ETDEWEB)

    Coron, N.; Gironnet, J.; Marcillac, P. de; Martinez, M.; Redon, T.; Torres, L. [Universite Paris-Sud 11 et CNRS (UMR 8617), Institut d' Astrophysique Spatiale, Orsay (France); Cuesta, C.; Garcia, E.; Ginestra, C.; Ortigoza, Y.; Pobes, C.; Puimedon, J.; Salinas, A.; Sarsa, M.L. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Watrin, A. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Universite Louis Pasteur, Ecole nationale superieure de physique de Strasbourg (ENSPS), Illkirch (France)

    2012-06-15

    The ROSEBUD Collaboration has dedicated several underground runs to study different types of bolometers, mainly for the search of dark matter. Some of these runs, profiting from the good energy resolution of one bolometer of BGO and the ultra-low background of the underground laboratory of Canfranc (LSC), allowed the measurement of the L/K electron capture ratio of the {sup 207}Bi decay to the 1633 keV level of {sup 207}Pb. This paper constitutes the first published measurement of this magnitude. (orig.)

  13. A predictive model of the temperature dependence of AC transport losses in (Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Guomin; Lin Liangzhen; Xiao Liye; Yu Yunjia [Key Laboratory of Applied Superconductivity, Chinese Academy of Sciences, Beijing 100190 (China); Schwartz, Justin [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Pamidi, Sastry V [Center for Advanced Power Systems, Florida State University, Tallahassee, FL 32310 (United States)

    2011-08-15

    Critical currents and AC losses of (Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} superconducting tapes were measured in self-field as a function of temperature. The experimental data of the temperature dependence of critical current were compared with calculated results. An approach to calculating AC losses as a function of temperature was developed and the calculated AC losses were compared with the measured data. The study shows that AC losses at any temperature can be estimated using the model from the critical parameters or from the measured AC loss factor at a certain temperature, such as 77 K.

  14. Effect of elastic stress on the resistivity and Tc of (Bi,Pb) sub 2 Sr sub 2 Ca sub n-1 Cu sub n O sub x for n = 2 or 3

    Energy Technology Data Exchange (ETDEWEB)

    Tessema, G.X.; Chen Xinfen; Skove, M.J. (Dept. of Physics and Astronomy, Clemson Univ. (United States))

    1991-12-01

    We have measured the effect of elastic uniaxial stress {sigma} in the a direction on the superconducting transition temperature Tc of (Bi, Pb){sub 2}Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub x} (n= 2 or 3, 2212 and 2223). We find dT/d{sigma}{sub 11}=-10{+-}2 K/GPa for 2212 and -6{+-}2 for the 2223 compounds. Our estimate of the change in Tc with a fractional change in the c axis spacing leads to two possible results, 7.3 K/% and -0.6 K/%. (orig.).

  15. d + Au hadron correlation measurements at PHENIX

    Energy Technology Data Exchange (ETDEWEB)

    Sickles, Anne M., E-mail: anne@bnl.gov

    2014-06-15

    In these proceedings, we discuss recent results from d + Au collisions in PHENIX ridge related measurements and their possible hydrodynamic origin. We present the v{sub 2} at midrapidity and measurements of the pseudorapidity dependence of the ridge, distinguishing between the d-going and Au-going directions. We investigate the possible geometrical origin by comparing v{sub 2} in d + Au to that in p + Pb, Au + Au and Pb + Pb collisions. Future plans to clarify the role of geometry in small collision systems at RHIC are discussed.

  16. Oxidized Ni/Au Transparent Electrode in Efficient CH3 NH3 PbI3 Perovskite/Fullerene Planar Heterojunction Hybrid Solar Cells.

    Science.gov (United States)

    Lai, Wei-Chih; Lin, Kun-Wei; Wang, Yuan-Ting; Chiang, Tsung-Yu; Chen, Peter; Guo, Tzung-Fang

    2016-05-01

    The successful application of a Ni/Au transparent electrode for fabricating efficient perovskite-based solar cells is demonstrated. Through interdiffusion of the Ni/Au bilayer, Au forms an interconnected metallic network structure as the transparent electrode. Ni diffuses to the bilayer surface and oxidizes into NiOx becoming an appropriate electrode interlayer. These ITO- and PSS-free devices have potential applications in the design of future cost-effective, low-weight, and stable solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. High-T{sub c} superconductivity in Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 2+x}O{sub y} compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Zahida; Maqsood, Asghari; Maqsood, Muhammad; Ramay, S.M.; Yousaf, Mohammad [Thermal Physics Laboratory, Department of Physics, Quaid-I-Azam University, Islamabad (Pakistan); Anwar-ul-Haq [Metallurgy Division, Dr A Q Khan Research Laboratories, Kahuta, Rawalpindi (Pakistan)

    1996-05-01

    Superconducting samples with the nominal composition Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 2+x}O{sub y} (x = 1.6, 1.8, 2.0) have been prepared by a solid state reaction technique. The resistivity data reveal the occurrence of multi phases in all the samples. By a process of ageing over 2 years then re annealing, a dramatic increase in T{sub c} was observed in the above system for x=2.0. We achieved zero resistance at 130 K, which is the highest in the composition Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 2+x}O{sub y} (x = 1.6, 1.8, 2.0) reported so far but the recipe is often not reproducible. This shows that the system is sensitive to Cu composition and to the conditions of preparation. Furthermore, long storage leads to a deterioration in the superconducting properties. X-ray diffraction studies show that these samples mainly contain the (2223) phase. However, in each sample, a few lines could not be indexed, which may indicate the presence of some new phase. (author)

  18. A rapid, partial leach and organic separation for the sensitive determination of Ag, Bi, Cd, Cu, Mo, Pb, Sb, and Zn in surface geologic materials by flame atomic absorption

    Science.gov (United States)

    Viets, J.G.; Clark, J.R.; Campbell, W.L.

    1984-01-01

    A solution of dilute hydrochloric acid, ascorbic acid, and potassium iodide has been found to dissolve weakly bound metals in soils, stream sediments, and oxidized rocks. Silver, Bi, Cd, Cu, Mo, Pb, Sb, and Zn are selectively extracted from this solution by a mixture of Aliquat 336 (tricaprylyl methyl ammonium chloride) and MIBK (methyl isobutyl ketone). Because potentially interfering major and minor elements do not extract, the organic separation allows interference-free determinations of Ag and Cd to the 0.05 ppm level, Mo, Cu, and Zn to 0.5 ppm, and Bi, Pb, and Sb to 1 ppm in the sample using flame atomic absorption spectroscopy. The analytical absorbance values of the organic solution used in the proposed method are generally enhanced more than threefold as compared to aqueous solutions, due to more efficient atomization and burning characteristics. The leaching and extraction procedures are extremely rapid; as many as 100 samples may be analyzed per day, yielding 800 determinations, and the technique is adaptable to field use. The proposed method was compared to total digestion methods for geochemical reference samples as well as soils and stream sediments from mineralized and unmineralized areas. The partial leach showed better anomaly contrasts than did total digestions. Because the proposed method is very rapid and is sensitive to pathfinder elements for several types of ore deposits, it should be useful for reconnaissance surveys for concealed deposits. ?? 1984.

  19. Theory versus experiment for a family of single-layer compounds with a similar atomic arrangement: (Tl,X )/Si(111 )√{3 }×√{3 }(X =Pb,Sn,Bi,Sb,Te,Se)

    Science.gov (United States)

    Matetskiy, A. V.; Kibirev, I. A.; Mihalyuk, A. N.; Eremeev, S. V.; Gruznev, D. V.; Bondarenko, L. V.; Tupchaya, A. Y.; Zotov, A. V.; Saranin, A. A.

    2017-08-01

    Two-dimensional compounds made of one monolayer of Tl and one-third monolayer of Pb, Bi, Te, or Se (but not of Sn or Sb) on Si(111) have been found to have a similar atomic arrangement which can be visualized as a √{3 }×√{3 } -periodic honeycomb network of chained Tl trimers with atoms of the second adsorbate occupying the centers of the honeycomb units. Structural and electronic properties of the compounds have been examined in detail theoretically using density functional theory (DFT) calculations and experimentally using low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), and angle-resolved photoelectron spectroscopy (ARPES) observations. It has been found that though structural parameters of the compounds are very similar for all species, the only common feature of their band structure is a considerable spin-splitting of the surface-state bands, while other basic electronic properties vary greatly with a change of species. The Tl-Pb compound is strongly metallic with two metallic surface-state bands; the Tl-Bi compound is also metallic but with a single metallic band; the Tl-Te and Tl-Se compounds appear to be insulators.

  20. Synthesis, Properties and Crystal Structure of a Novel Coordinated Polymer: {(H2en)(H3O)[(BiPb(C2O4)4(H2O)2)]·2(H2O)}n

    Institute of Scientific and Technical Information of China (English)

    GUO Wen-Jun; ZHANG Han-Hui; HUANG Chang-Cang; SUN Rui-Qing; CHEN Yi-Ping; CAO Yan-Ning

    2005-01-01

    A novel oxalate compound {(H2en)(H3O)[BiPb(C2O4)4(H2O)2]·2(H2O)}n 1 (en = ethylenediamine) containing lead and bismuth has been synthesized by hydrothermal methods, and structurally characterized by X-ray single-crystal diffraction. It crystallizes in monoclinic, space group P21/c with a = 11.6160(1), b = 12.7426(1), c = 15.5683(5) (A), β = 108.442(4)°, BiPbC10N2O21H21, Mr = 921.46, V = 2186.0(4) (A)3, Z = 4, Dc = 2.800 g/cm3, F(000) = 1712 and μ(MoKα) = 15.837 mm-1. The final R = 0.0502 and wR = 0.1261 for 3391 observed reflections with I > 2(σI). The title com- pound consists of 2-D polyanions and protonized organic amine cations, and they are combined to each other by static attractive force and H-bonds to form the so-called organic-inorganic hybrid material.

  1. 可用于小型铅铋冷快堆的核能制氢技术分析%Technical Analysis of Nuclear Hydrogen Production in Small Pb-Bi Cooled Fast Reactor

    Institute of Scientific and Technical Information of China (English)

    孙征; 吴晓春; 李龙; 邵静

    2016-01-01

    核能制氢作为一种有前景的大规模制氢方法,得到广泛研究。该文介绍了适用于核能制氢的反应堆堆型,以及可用于核能制氢的主要方法,并对可用于小型铅铋冷快堆的核能制氢技术进行了分析。分析结果表明,小型铅铋冷快堆制氢的潜在技术路线为热化学裂解水溴钙循环或甲烷直接裂解法。%As a promising massive way,nuclear hydrogen production is being extensively investigated across the world.In this paper,the reactor types and main methods which could be used in nuclear hydrogen production were introduced,and the techniques used in Small Pb-Bi cooled fast reactor for nuclear hydrogen production were investigated.As a result,the potential technical path in Small Pb-Bi cooled fast reactor for nuclear hydrogen production were Ca-Br-Fe thermo-chemical process and methane direct pyrolysis method.

  2. Dielectric and magnetic properties of Ta sub 2 O sub 5 -doped PrFeO sub 3 -PbTiO sub 3 and PrFeO sub 3 -BiFeO sub 3 ceramics

    CERN Document Server

    Kim, J S; Choi, Y N; Jang, P W

    2003-01-01

    Polarization-electric field (P-E) and magnetization-magnetic field (M-H) hysteresis curves have been characterized in the solid solutions of (1-x)PrFeO sub 3 -xPbTiO sub 3 +yTa sub 2 O sub 5 (y = 0-0.015 mole) and 0.2PrFeO sub 3 -0.8BiFeO sub 3. Neutron and X-ray diffraction data were collected for crystal structural analysis. The (1-x)PrFeO sub 3 -xPbTiO sub 3 were ferromagnetic at 0.2 = 0.7 from Pbnm (a = 5.552, b = 5.540 A, c = 7.833 A) to I4cm (a = b = 5.54 A, c = 7.841A) The structural analysis indicates that the solid solutions are ferroelectric only at x > 0.6. The 0.2PrFeO sub 3 -0.8BiFeO sub 3 showed a spontaneous magnetization of 0.3 emu/g at room temperature and remanent polarization P sub r of 0.6 mu C/cm sup 2. Addition of Ta sub 2 O sub 5 substantially changed the magnetic properties. The antiferromagnetic ordering is considered not to have a direct relationship with the weak ferromagnetism observed in this system. (author)

  3. Experimental Cross Sections for Reactions of Heavy Ions and 208Pb, 209Bi, 238U, and 248Cm Targets

    Energy Technology Data Exchange (ETDEWEB)

    Patin, Joshua Barnes [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    The study of the reactions between heavy ions and 208Pb, 209Bi, 238U, and 248Cm Cm targets was performed to look at the differences between the cross sections of hot and cold fusion reactions. Experimental cross sections were compared with predictions from statistical computer codes to evaluate the effectiveness of the computer code in predicting production cross sections. Hot fusion reactions were studied with the MG system, catcher foil techniques and the Berkeley Gas-filled Separator (BGS). 3n- and 4n-exit channel production cross sections were obtained for the 238U(18O,xn)256-xFm, 238U(22Ne,xn)260-xNo, and 248Cm(15N,xn)263-xLr reactions and are similar to previous experimental results. The experimental cross sections were accurately modeled by the predictions of the HIVAP code using the Reisdorf and Schaedel parameters and are consistent with the existing systematics of 4n exit channel reaction products. Cold fusion reactions were examined using the BGS. The 48Pb(238Ca,xn)256-xNo, 208Pb(50Ti,xn)258-xRf, 208Pb(51V,xn)259-xDb, 50Bi(238Ti,xn)259-xDb, and 209Bi(51V,xn)260-xSg reactions were studied. The experimental production cross sections are in agreement with the results observed in previous experiments. It was necessary to slightly alter the Reisdorf and Schaedel parameters for use in the HIVAP code in order to more accurately model the experimental data. The cold fusion experimental results are in agreement with current 1n- and 2n-exit channel systematics.

  4. The ''irreversibility line'' of Bi sub 2-x Pb sub x Sr sub 2 Ca sub 2 Cu sub 3 O sub 10 : a possible breakdown of an intrinsic proximity effect

    Energy Technology Data Exchange (ETDEWEB)

    Rango, P. de; Giordanengo, B.; Tournier, R.; Sulpice, A.; Chaussy, J.; Deutscher, G.; Genicon, J.L.; Lejay, P. (Centre National de la Recherche Scientifique, 38 - Grenoble (FR). Centre de Recherche sur les Tres Basses Temperatures); Retoux, R.; Raveau, B. (Institut des Sciences de la Matiere du Rayonnement (ISMRA), 14 - Caen (FR))

    1989-09-01

    The study of the magnetization ''irreversibility line'' of a Bi{sub 2-x}Pb{sub x}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} compound with a critical temperature T{sub c} of 110 K is presented. At low temperatures, we observe H{sup *}{approx} exp (-T/T{sub 0}) and close to T{sub c} H{sup *}{approx} (1-T/T{sub c}){sup 3/2}. The reversible magnetization as a function of the magnetic field H obeys the laws calculated for the Abrikosov flux lattice of an ideal superconductor when H{sub cl}<BiO-BiO-SrO layers, the superconducting ones being the 3 CuO layers. The strong dependence of the critical current with magnetic field is explained by the weakening of the correlation energy of vortices at the phase transition corresponding to the breakdown by the magnetic field of an induced superconductivity in the normal laminae.

  5. ab-plane optical spectra of iodine-intercalated Bi1.9Pb0.1Sr2CaCu2O8+δ: Normal and superconducting properties

    Science.gov (United States)

    Liu, H. L.; Tanner, D. B.; Berger, H.; Margaritondo, G.

    1999-04-01

    We report on the ab-plane optical reflectance of an iodine-intercalated Bi1.9Pb0.1Sr2CaCu2O8+δ single crystal in the 80-40 000 cm-1 (10 meV-5 eV) frequency range and at temperatures between 10 and 300 K. As compared to the iodine-free Bi2Sr2CaCu2O8+δ, we find that the visible-ultraviolet interband transitions are strongly modified after intercalation. Estimates of the low-frequency spectral weight indicate that there is an increase of hole concentration in the CuO2 planes. This behavior is a consequence of charge transfer between intercalated iodine atoms and the CuO2 sheets leading to an ionized iodine species. The ab-plane optical conductivity is analyzed in both the one-component and the two-component pictures, suggesting that the intercalated iodine does not have any significant effect on the in-plane scattering rate. In the superconducting state, a sum-rule evaluation finds that the superfluid contains about 25% of the total doping-induced, or nearly 86% of the free-carrier oscillator strength in the normal state. The value of the superconducting penetration depth is estimated to be 1980 Å, slightly larger than the 1860 Å found in iodine-free Bi2Sr2CaCu2O8+δ.

  6. Mesure de la production de J/psi en collisions p-Pb au LHC avec le spectromètre à muons d'ALICE

    CERN Document Server

    Lakomov, Igor

    Hard probes represent one of the hottest topics of the modern high energy physics. The production mechanism of quarkonia (mesons composed of a charm or beauty quark and its antiquark) in hadronic collisions is of particular interest. The suppression of J/psi and other charmonium states was predicted as one of the first signatures of the Quark Gluon Plasma (QGP) formation and was seen at RHIC and SPS. It was also studied at the LHC in Pb-Pb collisions. However, other effects can affect the charmonium production in Pb-Pb collisions without the presence of the QGP. These effects are inherent to the use of nuclei and are called “Cold Nuclear Matter” (CNM) effects. They can be studied in p-Pb collisions. This thesis is dedicated to the studies of J/psi production in p-Pb collisions at the LHC at a center of mass energy of 5.02 TeV per nucleon pair. J/psi production is studied as a function of transverse momentum, rapidity and event activity. These results represent a significant step to better understanding of...

  7. Corrosion mechanism of T91 steel by Pb-Bi eutectic used as spallation target: importance for accelerator driven system; Mecanisme de corrosion de l'acier T91 par l'eutectique Pb-Bi utilise comme materiau de cible de spallation: importance pour les reacteurs hybrides

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, L

    2005-10-15

    The aim of this work has been to determine the oxidation mechanism of the martensitic steel T91 in the Pb-Bi liquid eutectic alloy, saturated in oxygen, at 470 C, in order to develop a long-term predictive model of the oxidation kinetics of the steel. This work enters in the framework of the lifetime studies of the spallation module demonstrator: MEGAPIE for the researches on hybrid reactors. An experimental characterization of the oxide layers has been carried out as well as the oxidation kinetics of the T91 steel. An oxidation mechanism has been elaborated from these experimental results and then simulated. The oxide layer formed at the T91 surface presents a duplex structure constituted by a magnetite external layer and a spinel Fe-Cr internal layer. A growth mechanism of the oxide layers has been proposed: the growth of the magnetite layer seems to be limited by the iron diffusion in the lattice of the duplex oxide layer. In parallel, an auto-regulation mechanism seems to govern the growth of the Fe-Cr spinel layer. This mechanism includes a non-limiting step of the oxygen diffusion in the oxide layer (by liquid way in the nano-channels of lead), as well as a limiting step of iron diffusion in the lattice of the oxide layer. In considering the proposed oxidation mechanisms, a simulation of the growth of the two oxide layers is carried out and compared to the long-time oxidation growth kinetics. The good agreement between the experimental results allows, finally, to strengthen the proposition of a long-term growth kinetic oxidation mechanism of the oxide layers. (O.M.)

  8. Bi-based superconductor

    Directory of Open Access Journals (Sweden)

    S E Mousavi

    2009-08-01

    Full Text Available   In this paper, Bi-Sr-Ca-Cu-O (BCSCCO system superconductor is made by the solid state reaction method. The effect of doping Pb, Cd, Sb, Cu and annealing time on the critical temperature and critical current density have been investigated. The microstructure and morphology of the samples have been studied by X-ray diffraction, scanning electron microscope and energy dispersive X-ray. The results show that the fraction of Bi-2223 phase in the Bi- based superconductor, critical temperature and critical current density depend on the annealing temperature, annealing time and the kind and amount of doping .

  9. A comparative study regarding effects of interfacial ferroelectric Bi4Ti3O12 (BTO) layer on electrical characteristics of Au/-Si structures

    Indian Academy of Sciences (India)

    M Yildirim; M Gökçen

    2014-04-01

    Present study focuses on the effects of interfacial ferroelectric BTO layer on the electrical characteristics of Au/-Si structures, hence Au/-Si (MS) and Au/BTO/-Si (MFS) structures were fabricated and admittance measurements (capacitance–voltage: - and conductance–voltage: G/-) of both structures were conducted between 10 kHz and 1 MHz at room temperature. Results showed that - and G/- characteristics were affected not only by frequency but also through deposition of BTO layer. Some effects can be listed as sharper peaks in - plots, higher capacitance and conductance values. Structure’s series resistance (s) also decreased due to BTO layer. Interface states (ss) profiles of the structures were obtained using Hill–Coleman and high-low frequency capacitance (HF - LF). Some of the main electrical parameters were extracted from -2- plots using depletion capacitance approach. Furthermore, current–voltage characteristics of MS and MFS structures were presented.

  10. Electroreduction of Peroxide on Au(100) Surface Modified with Underpotentially Deposited Bismuth

    Science.gov (United States)

    Hara, Masanori; Nagahara, Yoshiki; Yoshimoto, Soichiro; Inukai, Junji; Itaya, Kingo

    2004-10-01

    The adlayer structure of Bi underpotentially deposited on Au(100) was investigated in a HClO4 solution using in-situ scanning tunneling microscopy. The underpotential deposition of Bi was found to occur in three steps. The electrochemical reduction rate of H2O2 on the Bi-modified Au(100) surface was the highest for an intermediate coverage of Bi.

  11. Switchable photovoltaic effect in Au/Bi{sub 0.9}La{sub 0.1}FeO{sub 3}/La{sub 0.7}Sr{sub 0.3}MnO{sub 3} heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Rongli, E-mail: gaorongli2008@163.com [School of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing, 401331 (China); Chongqing Key Laboratory of Nano/Micro Composite Materials and Devices, Chongqing, 401331 (China); Fu, Chunlin; Cai, Wei; Chen, Gang; Deng, Xiaoling; Cao, Xianlong [School of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing, 401331 (China); Chongqing Key Laboratory of Nano/Micro Composite Materials and Devices, Chongqing, 401331 (China)

    2016-09-15

    Bi{sub 0.9}La{sub 0.1}FeO{sub 3} (BLFO) films were fabricated on La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO)/SrTiO{sub 3}(STO)(001) substrates by pulsed laser deposition. The ferroelectric photovoltaic characteristics of Au/BLFO/LSMO heterostructures were studied under green light illumination. The open circuit voltage and short circuit current were observed to be positive and negative values under weak light illumination in the as-grown self-poled downward BLFO thin films, while they changed the signs when the light intensity is strong. On the contrary, this photovoltaic properties can be switched when the BLFO films were in poled up state. The photovoltaic effect was also strongly dependent on the polarization direction, incident light intensity and the distribution of oxygen vacancies. As a result, the sign of open circuit voltage and short circuit current could be independent of the direction of polarization. We believe that the switchable diode and photovoltaic effects can be explained well using the concepts of Schottky barrier modulation by polarization flipping and of oxygen vacancies and the distribution of oxygen vacancies at Au/BLFO or BLFO/LSMO interface. Our work provides deep insights into the nature of diode and photovoltaic effects in ferroelectric films, implying an effective approach to improve photovoltaic effect by tuning oxygen vacancies in ferroelectric materials. - Highlights: • Pure phase Bi{sub 0.9}La{sub 0.1}FeO{sub 3} thin films were grown using pulsed laser deposition. • The as grown films were self poled and the polarization direction is downward. • The switchable photovoltaic effect depend on ferroelectric polarization directions. • Photovoltaic effect can be switched by changing the intensity of incident radiation. • Depolarization field and oxygen vacancies together induce the photovoltaic effect.

  12. High pressure synthesis and properties of Bi{sub 0.5}Pb{sub 0.5}CrO{sub 3}: A novel Cr{sup 4+}/Cr{sup 3+} perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Pirrotta, Ivan [Dpto. Química Inorgánica, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Schmidt, Rainer [Dpto. Física Aplicada III, Facultad de CC. Físicas, GFMC, Universidad Complutense de Madrid, 28040 Madrid (Spain); Unidad Asociada “Laboratorio de heteroestructuras con aplicación en spintrónica”, UCM/CSIC, Sor Juana Ines de la Cruz, 3, Cantoblanco E-28049 Madrid (Spain); Dos Santos-García, Antonio J. [Dpto. Química Inorgánica, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Dpto. de Química Industrial y Polímeros, Escuela Universitaria de Ingeniería Técnica Industrial (EUITI), Universidad Politécnica de Madrid, C/Ronda de Valencia, 3, E-28012 Madrid (Spain); Garcia-Hernandez, Mar [Instituto de Ciencias de Materiales de Madrid—Consejo Superior de Investigaciones Cientìficas (ICMM-CSIC), Sor Juana Inés de la Cruz, 3, Cantoblanco, E-28049 Madrid (Spain); Morán, Emilio, E-mail: emoran@quim.ucm.es [Dpto. Química Inorgánica, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); and others

    2015-05-15

    We have synthesized a new Bi{sub 0.5}Pb{sub 0.}5CrO{sub 3} perovskite phase by means of a high pressure reaction at 70 kbar and 1000 °C. The distorted orthorhombic perovskite structure can be indexed in the space group Pnma with lattice parameters a=5.4768 (1) Å, b=7.7450 (2) Å, and c=5.4574 (1) Å at room temperature, but undergoes a structural phase transition and enters into a P2{sub 1}/m monoclinic distorted perovskite phase below 150 K with a=5.4173 (2), b=7.7286 (4) and c=5.4930 (3). The structural transition is coincident with the onset of magnetic interactions. At lower temperatures a weak ferromagnetic structure is evident related to antiferromagnetic Cr-spin canting and a spin-glass transition is observed at ≈40 K. The semiconducting-type electrical resistivity is relatively low, associated with Cr{sup 3+}/Cr{sup 4+} electron hopping, and shows considerable magneto-resistance (up to 15%). Due to the low resistivity the dielectric permittivity ε{sub r} could be determined only below T<80 K to be ≈300 and did not show any strong temperature-dependence. Ferroelectricity was not detected in the T-range investigated and no magnetocapacitance effects were observed. - Graphical abstract: A new Bi{sub 0.5}Pb{sub 0.}5CrO{sub 3} perovskite phase has been synthesized under high pressure (70 kbar) and high temperature (1000 °C) conditions. The room temperature structure is orthorhombic and can be indexed in the space group Pnma but below 150 K undergoes a structural phase transition and enters into a P2{sub 1}/m monoclinic distorted perovskite phase. The structural transition is coincident with the onset of magnetic interactions. Mott variable-range hopping charge transport and magnetoresistance effects are evident. - Highlights: • A new Bi{sub 0.5}Pb{sub 0.}5CrO{sub 3} perovskite has been synthesized under HP/HT conditions. • An orthorhombic-to monoclinic phase transition takes place at 150 K. • The structural transition is coincident with the onset

  13. U-Pb, Re-Os, and 40Ar/39Ar geochronology of the Nambija Au-skarn and Pangui porphyry Cu deposits, Ecuador: implications for the Jurassic metallogenic belt of the Northern Andes

    Science.gov (United States)

    Chiaradia, Massimo; Vallance, Jean; Fontboté, Lluis; Stein, Holly; Schaltegger, Urs; Coder, Joshua; Richards, Jeremy; Villeneuve, Mike; Gendall, Ian

    2009-05-01

    New U-Pb, Re-Os, and 40Ar/39Ar dates are presented for magmatic and hydrothermal mineral phases in skarn- and porphyry-related ores from the Nambija and Pangui districts of the Subandean zone, southeastern Ecuador. Nambija has been one of the main gold-producing centers of Ecuador since the 1980s due to exceptionally high-grade ores (average 15 g/t, but frequently up to 300 g/t Au). Pangui is a recently discovered porphyry Cu-Mo district. The geology of the Subandean zone in southeastern Ecuador is dominated by the I-type, subduction-related, Jurassic Zamora batholith, which intrudes Triassic volcanosedimentary rocks. The Zamora batholith is in turn cut by porphyritic stocks, which are commonly associated with skarn formation and/or porphyry-style mineralization. High precision U-Pb and Re-Os ages for porphyritic stocks (U-Pb, zircon), associated prograde skarn (U-Pb, hydrothermal titanite), and retrograde stage skarn (Re-Os, molybdenite from veins postdating gold deposition) of the Nambija district are all indistinguishable from each other within error (145 Ma) and indicate a Late Jurassic age for the gold mineralization. Previously, gold mineralization at Nambija was considered to be Early Tertiary based on K-Ar ages obtained on various hydrothermal minerals. The new Jurassic age for the Nambija district is slightly younger than the 40Ar/39Ar and Re-Os ages for magmatic-hydrothermal minerals from the Pangui district, which range between 157 and 152 Ma. Mineralization at Nambija and Pangui is associated with porphyritic stocks that represent the last known episodes of a long-lived Jurassic arc magmatism (˜190 to 145 Ma). A Jurassic age for mineralization at Nambija and Pangui suggests that the Northern Andean Jurassic metallogenic belt, which starts in Colombia at 3° N, extends down to 5° S in Ecuador. It also adds a new mineralization style (Au-skarn) to the metal endowment of this belt.

  14. Preresidue'' light charged particles from [sup 28]Si+[sup 165]Ho, [sup 16]O+[sup 197]Au, and [sup 16]O+[sup 208]Pb fusion

    Energy Technology Data Exchange (ETDEWEB)

    Fineman, B.J.; Brinkmann, K.; Caraley, A.L.; Gan, N.; McGrath, R.L.; Velkovska, J. (Physics Department, State University of New York at Stony Brook, Stony Brook, New York 11794 (United States))

    1994-10-01

    Proton and [alpha]-particle spectral shapes and multiplicities have been measured in coincidence with evaporation residues from 145 to 220 MeV [sup 28]Si+[sup 165]Ho and 115 and 140 MeV [sup 16]O+[sup 197]Au,[sup 208]Pb fusion reactions. Evaporation residues were separated using an electrostatic deflector and detected with large area surface barrier detectors. Light charged particles were detected at forward and backward angles with 14 single NaI detectors. In the context of the statistical model, the charged particle spectra provide information about the shapes and level densities of the emitting systems. Deformed emitters are inferred, and to a varying degree, an energy-dependent level density parameter is compatible with the data in each of the three cases. Implications for current fusion and fission dynamics studies are discussed.

  15. Synthesis of Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} superconductor

    Science.gov (United States)

    Smith, M.G.

    1996-10-29

    Two-powder processes for the synthesis of superconducting (Bi, Pb)-2223/Ag-clad wires by the oxide-powder-in-the-robe are provided. The first precursor powder, of nominal stoichiometry CaCuO{sub x}, is a solution-synthesized mixture of Ca{sub 0.45}Cu{sub 0.55}O{sub 2} and CaO. Using these oxide precursor mixtures, superconducting tapes with well-aligned grains and reproducible critical current densities J{sub c} in the range of 20,000 to 26,000 A/cm{sup 2} at 75 K in self-field after annealing less than 200 hours were obtained. 2 figs.

  16. Effect of Ag additions on the Bi{sub 1}.6Pb{sub 0}.4Sr{sub 2}Co{sub 1}.8O{sub x} thermoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Diez, J. C.; Rasekh, S.; Constantinescu, G.; Torres, M. A.; Madre, M. A.; Sotelo, A.

    2013-05-01

    Bi{sub 1}.6Pb{sub 0}.4Sr{sub 2}Co{sub 1}.8O{sub x} thermoelectric ceramics with small Ag additions (0, 1, and 3 wt.%) have been successfully produced by a sol-gel method via nitrates. Microstructure has shown a reduction on the amount of secondary phases and an increase on the bulk density with increasing Ag contents. The microstructural evolution, as a function of Ag content, is confirmed with the electrical resistivity values which show an important decrease for the 3 wt.% Ag samples, leading to maximum power factor values of about 0.025 mW/K2.m at room temperature, which is about two times higher than the obtained for the Ag-free sintered samples. (Author) 40 refs.

  17. Effect of Ag additions on the Bi{sub 1}.6Pb{sub 0}.4Sr{sub 2}Co{sub 1}.8O{sub x} thermoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Diez, J. C.; Rasekh, S. H.; Constantinescu, G.; Torres, M. A.; Madre, M. A.; Sotelo, A.

    2013-06-01

    Bi{sub 1}.6Pb{sub 0}.4Sr{sub 2}Co{sub 1}.8O{sub x} thermoelectric ceramics with small Ag additions (0, 1, and 3 wt.%) have been successfully produced by a sol-gel method via nitrates. Microstructure has shown a reduction on the amount of secondary phases and an increase on the bulk density with increasing Ag contents. The microstructural evolution, as a function of Ag content, is confirmed with the electrical resistivity values which show an important decrease for the 3 wt.% Ag samples, leading to maximum power factor values of about 0.025 mW/K2.m at room temperature, which is about two times higher than the obtained for the Ag-free sintered samples. (Author)

  18. Synthesis and structural studies on (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}−xPbTiO{sub 3} piezoceramics

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Ashutosh, E-mail: akhilesh-bhu@yahoo.com; Pandey, Rishikesh, E-mail: akhilesh-bhu@yahoo.com; Anand, Shashwat, E-mail: akhilesh-bhu@yahoo.com; Singh, Akhilesh K., E-mail: akhilesh-bhu@yahoo.com [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005 (India)

    2014-04-24

    We present here the structural studies on (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}−xPbTiO{sub 3} (BMT-xPT) piezoceramics with x=0.28, 0.37 and 0.45 using powder x-ray diffraction data. Rietveld refinement of powder x-ray diffraction data reveals the tetragonal structure (space group P4mm) for the compositions with x>0.40 and rhombohedral (space group R3m) for the compositions with x<0.30 of BMT-xPT ceramics. The morphotropic phase boundary is found for the intermediate composition with 0.30

  19. Effects of gamma irradiation on optical and structural properties of PbO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Gopi [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Singh, Kulwant [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India)]. E-mail: kulwantsthind@yahoo.com; Manupriya [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Mohan, Shaweta [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Singh, Harvinder [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Bindra, Sukhleen [Department of Electronics Communication, Guru Nanak Dev University, Amritsar 143005 (India)

    2006-09-15

    Optical and structural properties of xPbO.2xBi{sub 2}O{sub 3}(1-3x)B{sub 2}O{sub 3} glasses of different composition have been studied using UV-VIS and FTIR spectroscopic techniques. Effects of gamma radiations on glass network and structural units have been studied by irradiating glass samples with a {sup 60}Co radioisotope to the overall dose of 2.5 kGy. It is shown that irradiation causes compaction of the borate network by breaking the bonds between trigonal elements, which leads to a decrease in the optical band gap energy. Changes in the atomic structure before and after the irradiation are observed and explained.

  20. Properties of compositionally graded (1-x)(Bi0.85La0.15)FeO3-xPbTiO3 ceramics fabricated by tape casting

    Science.gov (United States)

    Jin, Guoxi; Chen, Jianguo; Cheng, Jinrong

    2015-08-01

    Three types of (1-x)(Bi0.85La0.15)FeO3-xPbTiO3 (BLF-PT) compositionally graded ceramics (x = 0.38, 0.40, 0.415 and 0.43) were fabricated using a lamination process based on the non-aqueous tape casting method. Scanning electron microscope images showed that the compositionally graded ceramics possessed dense microstructures without obvious cracks. The dielectric, ferroelectric and piezoelectric properties of the BLF-PT ceramics were sensitive to the composition distributions in the thickness direction. The BLF-PT ceramics with monotonic variation of PT content (in the thickness direction) exhibited the best piezoelectric properties. The tip displacement of compositionally graded piezoelectric ceramics reached up to ˜13.5 μm, which is about ten times higher than that of BLF-PT ceramics with single composition.

  1. Sulfur and oxygen isotopic study of Paleozoic sediment-hosted Zn-Pb(-Ag-Au-Ba-F) deposits and associated hydrothermal alteration zones in the Nome Complex, Seward Peninsula, Alaska

    Science.gov (United States)

    Shanks, W.C. Pat; Slack, John F.; Till, Alison B.; Thurston, Roland; Gemery-Hill, Pamela

    2014-01-01

    Results of sulfur and oxygen isotope studies of sedimentary exhalative (SEDEX) Zn-Pb(-Ag-Au-Ba-F) deposits hosted in metamorphosed Paleozoic clastic and carbonate rocks of the Nome Complex, Seward Peninsula, Alaska, are consistent with data for similar deposits worldwide. Stable isotopic studies of the Nome Complex are challenging because the rocks have undergone Mesozoic blueschist- and greenschist-facies metamorphism and deformation at temperatures estimated from 390–490 °C. Studies of sulfur and oxygen isotopes in other areas suggest that, in the absence of chemical and mineralogical evidence for metasomatism, the principal effect of metamorphism is re-equilibration between individual minerals at the temperature of metamorphism, which commonly leads to a narrowing of the overall range of isotope values for a suite of rocks, but generally does not significantly modify the average whole rock value for that suite. Sulfur isotope studies of the stratabound and locally stratiform sulfide lenses at the Aurora Creek-Christophosen deposit, which is of possible Late Devonian-early Carboniferous age, show a large range of δ34Ssulfide values from -9.7 to 39.4‰, suggesting multiple sulfur sources and possibly complex processes of sulfide formation that may include bacterial sulfate reduction, thermochemical sulfate reduction, and Rayleigh distillation. Low δ34S values probably represent bacterial sulfide minerals remobilized from the host metasedimentary rocks either during the original seafloor mineralization or are related to a Cretaceous mineralizing event that produced Au-vein and base-metal replacement deposits; the latter process is supported by Pb isotope data. The Wheeler North deposit is similar to Aurora Creek-Christophosen but does not have negative δ34S values. It also probably formed in an euxinic sub-basin.

  2. Electrical properties of Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3}–BiFeO{sub 3} multilayers on non-platinized silicon substrate

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Shankar, E-mail: shankardutta77@gmail.com [Solid State Physics Laboratory, DRDO, Lucknow Road, Timarpur, Delhi 110054 (India); Chatterjee, Ratnamala [Department of Physics, IIT Delhi, Hauz Khas, New Delhi 110016 (India)

    2015-08-15

    Highlights: • A Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3}/BiFeO{sub 3} multilayer film is deposited on a silicon substrate. • The phase, crystalline structure, and morphology of the film are studied. • The magnetic property of the film is studied. • In the absence of the bottom electrode, interdigitated terminal (IDTs) structures are fabricated on top of the film. • The electrical properties of the film are studied. - Abstract: In this study, a Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3}/BiFeO{sub 3} (PZT–BFO) multilayer film is deposited by the sol–gel technique on a silicon substrate. Prior to the multilayer deposition, a ZrO{sub 2} buffer layer is introduced. The multilayer thin film shows the polycrystalline phase-pure perovskite structures of BFO and PZT. Surface morphology study indicates that the grain size of the film varies from 20 to 30 nm. In the absence of the bottom electrode, the electrical properties of the film are studied in-plane by fabricating interdigitated terminals (IDTs) on top of the film. The inter-IDT line gap is kept large (10 μm) to avoid shorting due to unintentional particle contamination. The remnant polarization of the film is found to be ∼35 μC/cm{sup 2} at a 100-V bias. The dielectric constant of the film is found to be 650 at 1 kHz. The film also showed a low leakage current density of ∼4 × 10{sup −9} A/cm{sup 2} at 200 kV/cm.

  3. Optimized properties of xBiInO{sub 3}-(1-x)PbTiO{sub 3} thin films deposited by an RF-magnetron sputtering method

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ke-Xue; Zhang, Shu-Yi; Shui, Xiu-Ji [Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing (China); Wasa, Kiyotaka [Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing (China); Graduate School, Yokohama City University, Yokohama (Japan)

    2016-09-15

    Ferroelectric xBiInO{sub 3}-(1-x)PbTiO{sub 3} (x = 0.15, 0.20, 0.25, and 0.30) thin films are deposited on (101)SrRuO{sub 3}/(100)Pt/(100)MgO substrates by an RF-magnetron sputtering method. By adjusting the deposition conditions, the electric properties of the thin films are optimized. The ferroelectricities of the thin films show that the remnant polarizations (P{sub r}) decrease from 43 to 34 μC cm{sup -2} as x increases from 0.15 to 0.25, and the coercive fields (E{sub c}) are about 177 kV cm{sup -1}. The Curie temperatures (T{sub c}) increase from 580 to 650 C on increasing x from 0.15 to 0.30. The results illustrate that the xBI-(1-x)PT films have high ferroelectricities, high coercive fields, and high Curie temperatures simultaneously, which may have wide potential applications in high-temperature and -voltage environments. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Preparation and characterization of Ag-added Bi1.84Pb0.4Sr2Ca2.2Cu3O10+ bulk tube conductors for cryogen free superconducting magnet

    Indian Academy of Sciences (India)

    S N Ekbote; G K Padam; M Sharma; N K Arora; B S Khurana; R C Goel; D K Suri; N Mehra; B K Das

    2001-12-01

    Bulk tube conductors of Bi1.84Pb0.4Sr2Ca2.2Cu3O10+ with addition of silver varying from 0 to 25 wt% (not reported earlier) were systematically studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), electrical transport and a.c. susceptibility techniques. The tube conductors formed by cold isostatic pressing (CIP) of the powders obtained from spray drying method have been made successfully. It was found that Ag addition has not only affected the formation of the desired Bi-2223 phase and the microstructure of these large bulk tube samples thereby influencing on the critical current (c), it also reduces the contact resistance to minimize the cryogen losses. These variations have been found to be Ag content dependent. An optimized value of 10 wt% Ag has been found to produce the best quality tubes showing reproducible c value > 120 Amp at 77 K which is in general a requirement to energies of the cryogen free conventional/HTSC superconducting magnets below 20 K.

  5. Transport Barkhausen-like noise in uniaxially pressed Bi{sub 1.65}Pb{sub 0.35}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+{delta}}ceramic samples

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Fornaris, I. [Departamento de Ciencias Basicas, Universidad de Granma, Apdo. 21, P.O. Box 85100, Bayamo (Cuba); Govea-Alcaide, E. [Departamento de Fisica, Universidad de Oriente, Patricio Lumumba s/n, P.O. Box 90500, Santiago de Cuba (Cuba); Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05315-970 Sao Paulo, SP (Brazil); Alberteris-Campos, M. [Departamento de Engenharia Mecanica, Escola Politecnica, Universidade de Sao Paulo, 05508-900 Sao Paulo, SP (Brazil); Mune, P. [Departamento de Fisica, Universidad de Oriente, Patricio Lumumba s/n, P.O. Box 90500, Santiago de Cuba (Cuba); Jardim, R.F., E-mail: rjardim@if.usp.b [Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05315-970 Sao Paulo, SP (Brazil)

    2010-08-01

    We report on the detection of the transport Barkhausen-like noise (TBN) in polycrystalline samples of Bi{sub 1.65}Pb{sub 0.35}Sr{sub 2}Ca{sub 2} Cu{sub 3}O{sub 10+{delta}}(Bi-2223) which were subjected to different uniaxial compacting pressures. The transport Barkhausen-like noise was measured when the sample was subjected to an ac triangular-shape magnetic field (f {approx} 1 Hz) with maximum amplitude B{sub max} {approx} 5.5 mT, in order to avoid the flux penetration within the superconducting grains. Analysis of the TBN signal, measured for several values of excitation current density, indicated that the applied magnetic field in which the noise signal first appears, B{sub a}(t{sub i}), is closely related to the magnetic-flux pinning capability of the material. The combined results are consistent with the existence of three different superconducting levels within the samples: (i) the superconducting grains; (ii) the superconducting clusters; and (iii) the weak-links. We finally argue that TBN measurements constitute a powerful tool for probing features of the intergranular transport properties in polycrystalline samples of high-T{sub c} superconductors.

  6. Determination of As,Hg,Cd,Pb and Bi in gold concentrates by AFS%原子荧光光谱法测定金精矿中的砷汞镉铅铋

    Institute of Scientific and Technical Information of China (English)

    王菊; 陈永红; 苏广东; 孟宪伟; 王立臣

    2015-01-01

    研究建立了采用原子荧光光谱仪测定金精矿中砷、汞、镉、铅、铋的方法。通过对比实验选择了水浴溶样法作为砷、汞、铋的预处理方法,选择了盐酸、硝酸、高氯酸和氢氟酸混酸溶样法作为砷、铋、镉、铅的预处理方法。经过条件实验分别确定了两种预处理方法的最小称样量、试剂用量、水浴溶样法溶样时间、混酸溶样法定容介质酸度等最佳实验条件。该方法加入标准物质回收率为92.54%~125.10%,精密度(RSD,n=11)均小于10%,准确度小于8%。%The paper established a determination method of As,Hg,Cd,Pb and Bi in gold concentrates by AFS. Contrast test chose water bath dissolution as the pretreatment method of As,Hg and Bi,and the mixed acids dissolution with hydrochloric acid,nitric acid,perchloric acid and hydrofluoric acid for the pretreatment of As,Cd,Pb and Bi. Conditional experiments settled such optimal conditions as the minimum test portion weight,agent dosage,time for wa-ter bath dissolution and constant volume medium acidity respectively for the two pretreatment methods.The recovery rate with addition of standard substance is 92.54 % to 125.10 %,the precision rate(RSD,n=11) is less than 10%,and accuracy is less than 8 %.

  7. Effect of interface microstructure on the mechanical properties of Pb-free hybrid microcircuit solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Vianco, P.T.; Rejent, J.A.

    1998-08-01

    Although Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has well documented environmental and toxicity issues. Sandia National Laboratories is developing alternative solder materials to replace traditional Pb-containing alloys. The alloys are based on the Sn-Ag, Sn-Ag-Bi and Sn-Ag-Bi-Au systems. Prototype hybrid microcircuit (HMC) test vehicles have been developed to evaluate these Pb-free solders, using Au-Pt-Pd thick film metallization. Populated test vehicles with surface mount devices have been designed and fabricated to evaluate the reliability of surface mount solder joints. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC`s). Intermetallic compound (IMC) layer reaction products that form at the solder/substrate interface have been characterized and their respective growth kinetics quantified. Thicker IMC layers pose a potential reliability problem with solder joint integrity. Since the IMC layer is brittle, the likelihood of mechanical failure of a joint in service is increased. The effect of microstructure and the response of these different materials to wetting, aging and mechanical testing was also investigated. Solid-state reaction data for intermetallic formation and mechanical properties of the solder joints are reported.

  8. Electric field induced cubic to monoclinic phase transition in multiferroic 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Rishikesh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2014-10-20

    The results of x-ray diffraction studies on 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution poled at various electric fields are presented. After poling, significant value of planar electromechanical coupling coefficient (k{sub P}) is observed for this composition having cubic structure in unpoled state. The cubic structure of 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} transforms to monoclinic structure with space group Pm for the poling field ≥5 kV/cm. Large c-axis microscopic lattice strain (1.6%) is achieved at 30 kV/cm poling field. The variation of the c-axis strain and unit cell volume with poling field shows a drastic jump similar to that observed for strain versus electric field curve in (1 − x)Pb(Mg{sub 1/3}Nb{sub 2/3}) O{sub 3}-xPbTiO{sub 3} and (1 − x)Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3}.

  9. Influence of the initial Bi2223 phase content on microstructure development in Bi2223/Ag tapes

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yang, X P; Abrahamsen, Asger Bech;

    2010-01-01

    (Bi,Pb)2Sr2Ca2Cu3O10 (Bi2223) Ag-sheathed tapes were produced from precursors containing various amounts of pre-reacted Bi2223 phase obtained by means of controlled calcinations of the starting powder mixture. The evolution of the critical current density during the first 20h of the first heat...

  10. Ni-Based Catalysts for Low Temperature Methane Steam Reforming: Recent Results on Ni-Au and Comparison with Other Bi-Metallic Systems

    Directory of Open Access Journals (Sweden)

    Anna M. Venezia

    2013-06-01

    Full Text Available Steam reforming of light hydrocarbons provides a promising method for hydrogen production. Ni-based catalysts are so far the best and the most commonly used catalysts for steam reforming because of their acceptably high activity and significantly lower cost in comparison with alternative precious metal-based catalysts. However, nickel catalysts are susceptible to deactivation from the deposition of carbon, even when operating at steam-to-carbon ratios predicted to be thermodynamically outside of the carbon-forming regime. Reactivity and deactivation by carbon formation can be tuned by modifying Ni surfaces with a second metal, such as Au through alloy formation. In the present review, we summarize the very recent progress in the design, synthesis, and characterization of supported bimetallic Ni-based catalysts for steam reforming. The progress in the modification of Ni with noble metals (such as Au and Ag is discussed in terms of preparation, characterization and pretreatment methods. Moreover, the comparison with the effects of other metals (such as Sn, Cu, Co, Mo, Fe, Gd and B is addressed. The differences of catalytic activity, thermal stability and carbon species between bimetallic and monometallic Ni-based catalysts are also briefly shown.

  11. Petrology, geochemistry and U-Pb geochronology of magmatic rocks from the high-sulfidation epithermal Au-Cu Chelopech deposit, Srednogorie zone, Bulgaria

    Science.gov (United States)

    Chambefort, Isabelle; Moritz, Robert; von Quadt, Albrecht

    2007-10-01

    The Chelopech deposit is one of the largest European gold deposits and is located 60 km east of Sofia, within the northern part of the Panagyurishte mineral district. It lies within the Banat-Srednegorie metallogenic belt, which extends from Romania through Serbia to Bulgaria. The magmatic rocks define a typical calc-alkaline suite. The magmatic rocks surrounding the Chelopech deposit have been affected by propylitic, quartz-sericite, and advanced argillic alteration, but the igneous textures have been preserved. Alteration processes have resulted in leaching of Na2O, CaO, P2O5, and Sr and enrichment in K2O and Rb. Trace element variation diagrams are typical of subduction-related volcanism, with negative anomalies in high field strength elements (HFSE) and light element, lithophile elements. HFSE and rare earth elements were relatively immobile during the hydrothermal alteration related to ore formation. Based on immobile element classification diagrams, the magmatic rocks are andesitic to dacitic in compositions. Single zircon grains, from three different magmatic rocks spanning the time of the Chelopech magmatism, were dated by high-precision U-Pb geochronology. Zircons of an altered andesitic body, which has been thrust over the deposit, yield a concordant 206Pb/238U age of 92.21 ± 0.21 Ma. This age is interpreted as the crystallization age and the maximum age for magmatism at Chelopech. Zircon analyses of a dacitic dome-like body, which crops out to the north of the Chelopech deposit, give a mean 206Pb/238U age of 91.95 ± 0.28 Ma. Zircons of the andesitic hypabyssal body hosting the high-sulfidation mineralization and overprinted by hydrothermal alteration give a concordant 206Pb/238U age of 91.45 ± 0.15 Ma. This age is interpreted as the intrusion age of the andesite and as the maximum age of the Chelopech epithermal high-sulfidation deposit. 176Hf/177Hf isotope ratios of zircons from the Chelopech magmatic rocks, together with published data on the

  12. Optical and thermal investigation of GeO{sub 2}-PbO thin films doped with Au and Ag nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, E.A.; Carmo, A.P. [Laboratorio de Espectroscopia de Materiais, Departamento de Fisica, Universidade Federal de Juiz de Fora, Juiz de Fora-MG (Brazil); Bell, M.J.V., E-mail: mjbell@fisica.ufjf.br [Laboratorio de Espectroscopia de Materiais, Departamento de Fisica, Universidade Federal de Juiz de Fora, Juiz de Fora-MG (Brazil); Anjos, V. [Laboratorio de Espectroscopia de Materiais, Departamento de Fisica, Universidade Federal de Juiz de Fora, Juiz de Fora-MG (Brazil); Kassab, L.R.P. [Laboratorio de Tecnologia em Materiais Fotonicos e Optoeletronicos, Faculdade de Tecnologia de Sao Paulo, Sao Paulo (Brazil); Silva, D.M. da [Departamento de Engenharia de Sistemas Eletronicos, Escola Politecnica da USP, Sao Paulo, Sao Paulo (Brazil)

    2012-01-31

    The present work reports on the thermo-optical study of germanate thin films doped with Au and Ag nanoparticles. Transmission Electron Microscopy images, UV-visible absorption and Micro-Raman scattering evidenced the presence of nanoparticles and the formation of collective excitations, the so called surface plasmons. Moreover, the effects of the metallic nanoparticles in the thermal properties of the films were observed. The thermal lens technique was proposed to evaluate the Thermal Diffusivity (D) of the samples. It furnishes superficial spatial resolution of about 100 {mu}m, so it is appropriate to study inhomogeneous samples. It is shown that D may change up to a factor 3 over the surface of a film because of the differences in the nanoparticles concentration distribution.

  13. U-Pb zircon, geochemical and Sr-Nd-Hf-O isotopic constraints on age and origin of the ore-bearing intrusions from the Nurkazgan porphyry Cu-Au deposit in Kazakhstan

    Science.gov (United States)

    Shen, Ping; Pan, Hongdi; Seitmuratova, Eleonora; Jakupova, Sholpan

    2016-02-01

    Nurkazgan, located in northeastern Kazakhstan, is a super-large porphyry Cu-Au deposit with 3.9 Mt metal copper and 229 tonnage gold. We report in situ zircon U-Pb age and Hf-O isotope data, whole rock geochemical and Sr-Nd isotopic data for the ore-bearing intrusions from the Nurkazgan deposit. The ore-bearing intrusions include the granodiorite porphyry, quartz diorite porphyry, quartz diorite, and diorite. Secondary ion mass spectrometry (SIMS) zircon U-Pb dating indicates that the granodiorite porphyry and quartz diorite porphyry emplaced at 440 ± 3 Ma and 437 ± 3 Ma, respectively. All host rocks have low initial 87Sr/86Sr ratios (0.70338-0.70439), high whole-rock εNd(t) values (+5.9 to +6.3) and very high zircon εHf(t) values (+13.4 to +16.5), young whole-rock Nd and zircon Hf model ages, and consistent and slightly high zircon O values (+5.7 to +6.7), indicating that the ore-bearing magmas derived from the mantle without old continental crust involvement and without marked sediment contamination during magma emplacement. The granodiorite porphyry and quartz diorite porphyry are enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE) and depleted in high-field strength elements (HFSE), Eu, Ba, Nb, Sr, P and Ti. The diorite and quartz diorite have also LILE and LREE enrichment and HFSE, Nb and Ti depletion, but have not negative Eu, Ba, Sr, and P anomalies. These features suggest that the parental magma of the granodiorite porphyry and quartz diorite porphyry originated from melting of a lithospheric mantle and experienced fractional crystallization, whereas the diorite and quartz diorite has a relatively deeper lithospheric mantle source region and has not experienced strong fractional crystallization. Based on these, together with the coeval ophiolites in the area, we propose that a subduction of the Balkhash-Junggar oceanic plate took place during the Early Silurian and the ore-bearing intrusions and associated Nurkazgan

  14. Relaxor ferroelectric properties of the (1-2 x)BiScO3 · xPbTiO3 · xPbMg1/3Nb2/3O3 (0.30 ≤ x ≤ 0.46) system

    Science.gov (United States)

    Bush, A. A.; Kamentsev, K. E.; Bekhtin, M. A.; Segalla, A. G.

    2017-01-01

    X-ray diffraction, dielectric, piezoelectric, and pyroelectric studies have been performed on ceramic samples of (1-2 x)BiScO3 · xPbTiO3 · xPbMg1/3Nb2/3O3 (0.30 ≤ x ≤ 0.46) perovskite-like solid solutions. The solid solution symmetry was found to vary from the rhombohedral ( x ≤ 0.38) to tetragonal ( x ≥ 0.42) as x increases. The samples with 0.30 < x ≤ 0.42 have properties characteristic of relaxor ferroelectrics, namely the existence of a wide peak in the temperature dependence of the dielectric permittivity at T mɛ = 390-440 K that shifts to higher temperatures as the frequency increases, narrow unsaturated dielectric hysteresis loops, and an electric field-induced transition to the ferroelectric state at 318 K. The observed features of the dielectric, piezo-, and pyroelectric properties of these solid solutions are explained by the fact that they are relaxor ferroelectrics.

  15. Litochlebite, Ag2PbBi4Se8, a new selenide mineral species from Zalesi, Czech Republic: description and crystal structure

    DEFF Research Database (Denmark)

    Makovicky, Emil; Topa, Dan; Sejkora, Jiri;

    2011-01-01

    , and uranophane. Litochlebite is opaque, dark grey to black, has a dark grey streak and a metallic luster. No cleavage was observed; the mineral is brittle with an irregular fracture. The VHN10g microhardness 230 (227–234) kg/mm2 corresponds to a Mohs hardness of about 3; the calculated density is 7.90 g/cm3...... [Fo > 4s(Fo)] collected on a Bruker AXS diffractometer with a CCD detector and MoKa radiation. The crystal structure contains one lead site, four independent Bi sites, four silver sites and eight independent Se sites. One Ag site is an octahedrally coordinated (2 + 4) site in the pseudotetragonal...

  16. Laser Ablation ICP-MS Titanite U-Th-Pb Dating of the Tonglushan Cu-Fe-Au Skarn Deposit, Southeastern Hubei Province%Laser Ablation ICP-MS Titanite U-Th-Pb Dating of the Tonglushan Cu-Fe-Au Skarn Deposit,Southeastern Hubei Province

    Institute of Scientific and Technical Information of China (English)

    LI Jian-wei; DENG Xiao-dong; ZHOU Mei-fu; LIU Yong-sheng

    2009-01-01

    @@ Titanite (CaTi_2SiO_5) is an important accessory mineral not only in magnatic and metamorphic rocks,but also commonly in hydrothermal mineral deposits.It incorporates appreciable amounts (usually 10 ×10~(-6) s to 100 × 10~(-6) s) of U and Th into its structure and has a closure temperature of Pb diffusion higher than 660 ~ 700 ℃ (Scott and St-Onge, 1995),making it an ideal U-Th-Pb geochronometer.

  17. Mechanical properties of Pb-free solder alloys on thick film hybrid microcircuits

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Vianco, P.T.; Rejent, J.A.; Hosking, F.M.

    1998-03-10

    The technology drivers of the electronics industry continue to be systems miniaturization and reliability, in addition to addressing a variety of important environmental issues. Although the Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has drawn environmental concern due to its Pb content. The solder acts both as an electrical and mechanical connection within the different packaging levels in an electronic device. New Pb-free solders are being developed at Sandia National Laboratories. The alloys are based on the Sn-Ag alloy, having Bi and Au additions. Prototype hybrid microcircuit (HMC) test vehicles have been assembled to evaluate Pb-free solders for Au-Pt-Pd thick film soldering. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC`s). The mechanical properties of the joints were evaluated. The reflow profiles and the solid state intermetallic formation reaction will also be presented. Improved solder joint manufacturability and increased fatigue resistance solder alloys are the goals of these materials.

  18. Calculation of neutron cross sections for sup 9 sup 0 Zr, sup 2 sup 0 sup 8 Pb and sup 2 sup 0 sup 9 Bi in the energy range of 0.5-25 MeV by using the optical model potentials

    CERN Document Server

    Miah, M M H; Faruque, M R I

    2003-01-01

    Neutron total cross sections and differential elastic scattering cross sections for the nuclides sup 9 sup 0 Zr, sup 2 sup 0 sup 8 Pb and sup 2 sup 0 sup 9 Bi were calculated using different global spherical optical potential (SOP) parameter sets at neutron energies from 0.5-25 MeV. Calculated cross sections for the corresponding nuclides were compared with their experimental data obtained by the EXFOR file to select the best fit parameter sets. It is found that the parameter sets of Ferer Rapaport for sup 9 sup 0 Zr and Bechetti and Greenless for sup 2 sup 0 sup 8 Pb and sup 2 sup 0 sup 9 Bi are the best fitted set to obtain the experimental data of total cross sections and angular distributions of these nuclides. (author)

  19. CHANGES IN CRYSTAL STRUCTURE AND ELECTRONIC PROPERTIES RELATED TO TWO DIFFERENT BLOCKS IN Bi1.7Pb0.3Sr2Ca2Cu3Ox%Bi1.7Pb0.3Sr2Ca2Cu3Ox超导体中晶体结构和电子性能与两个结构块的关联

    Institute of Scientific and Technical Information of China (English)

    张莉; 杨锟; 张酣

    2000-01-01

    用变温X-射线衍射,扫描量热分析,热重分析对精心制作的Bi1.7Pb0.3Sr2Ca2Cu3Ox超导样品在后处理前和后处理后从液氮温度到熔点温度进行了分析,并对样品进行了XPS分析,载流子浓度和超导电性测量.实验发现,样品沿C方向的膨胀系数在低温区有两个反常,在高温区有两个热量和重量反常.结果分析表明,这两个反常与晶体结构中两个不同的结构块有关,即钙钛矿和盐岩结构块.实验发现,这两个结构块之间的失配,超导临界温度,样品中的氧含量,以及膨胀系数的变化之间有密切的关联.实验结果表明,了解两个不同结构块之间的相互作用对认识高温超导电性有重要作用.%The elaborated and well characterized Bi1.7Pb0.3Sr2Ca2Cu3Ox samples, as-prepared and annealed in different conditions, were studied by temperature dependent X-ray diffraction from liquid nitrogen temperature to melting point, differential scanning calorimetry, thermogravimetry, X-ray photoelectron spectroscopy, carrier concentration, and superconductivity measurements. Two changes of thermal expansion coefficient along the c direction in low temperature range and two thermal instabilities in high temperature range are observed, which suggests that the structure changes in this system is asssociated with two different blocks, i.e., perovskite and rock-salt blocks, of the unit cell. The changes in structure and in electronic properties related to these blocks are also observed. It is found that there is a close correlation among the mismatch between the two different blocks, value of Tc, oxygen content, and thermal expansion coefficient, and a roughly quantitative relationship is also obtained. The experimental results suppose that the interaction between different layers especially two different blocks, is of importance to understand the superconductivity in oxide superconductors.scholar in Department of Physics, Peking University.

  20. {open_quotes}Pre-residue{close_quotes} light charged particles from {sup 28}Si+{sup 165}Ho and {sup 16}O+{sup 197}Au, {sup 208}Pb fusion

    Energy Technology Data Exchange (ETDEWEB)

    Fineman, B.J.; Brinkmann, K.T.; Caraley, A.L.; Gan, N.; McGrath, R.L.; Velkovska, J.

    1993-10-01

    Proton and alpha particle spectral shapes and multiplicities have been measured in coincidence with evaporation residues from {sup 28}Si+{sup 165}Ho and {sup 16}O + {sup 197}Au, {sup 208}Pb fusion reactions. Our experiments used 145 to 220 MeV {sup 28}Si and 115 and 140 MeV {sup 16}O beams produced with the Stony Brook LINAC. ER`s were separated using an electrostatic deflector and detected with large area surface barrier detectors. Light charged particles were detected at forward and backward angles with fourteen single NaI detectors. In the context of the statistical model, charged particle spectra yield information about emission barriers and compound nucleus equilibrium level densities. These are significant ingredients in calculations determining fission timescales from other observables such as pre-scission neutron multiplicities or fusion-evaporation excitation functions. Results will also be compared to analyses of pre-scission charged particles from similar systems which required barrier reductions to describe measured spectra.

  1. Electron-Impact Ionization Cross Sections of H, He, N, O, Ar, Xe, Au, Pb Atoms and Their Ions in the Electron Energy Range from the Threshold up to 200 keV

    CERN Document Server

    Povyshev, V M; Shevelko, V P; Shirkov, G D; Vasina, E G; Vatulin, V V

    2001-01-01

    Single electron-impact ionization cross sections of H, He, N, O, Ar, Xe, Au, Pb atoms and their positive ions (i.e. all ionization stages) are presented in the electron energy range from the threshold up to 200 keV. The data-set for the cross sections has been created on the basis of available experimental data and calculations performed by the computer code ATOM. Consistent data for the ionization cross sections have been fitted by seven parameters using the LSM method. The accuracy of the calculated data presented is within a factor of 2 that in many cases is sufficient to solve the plasma kinetics problems. Contributions from excitation-autoionization and resonant-ionization processes as well as ionization of atoms and ions are not considered here. The results of the numerical calculations are compared with the well-known Lotz formulae for ionization of neutral atoms and positive ions. The material is illustrated by figures and includes tables of ionization cross sections, binding energies and fitting para...

  2. 3D modelling and sheath folding at the Falun pyritic Zn-Pb-Cu-(Au-Ag) sulphide deposit and implications for exploration in a 1.9 Ga ore district, Fennoscandian Shield, Sweden

    Science.gov (United States)

    Kampmann, Tobias C.; Stephens, Michael B.; Weihed, Pär

    2016-06-01

    Altered and mineralized rocks at the Falun pyritic Zn-Pb-Cu-(Au-Ag) sulphide deposit, situated in the Palaeoproterozoic Bergslagen ore district in the south-western part of the Fennoscandian Shield, have been metamorphosed at low-pressure, amphibolite-facies conditions and affected by ductile deformation. Using combined surface mapping of lithology and structure, drill core logging and microstructural work, the polyphase (D1 and D2) ductile deformation is demonstrated and a 3D model for the deposit created. Mineral associations include quartz, biotite, cordierite, anthophyllite, and minor almandine, andalusite and chlorite in silicate-rich altered rock, calcite or dolomite in marble and tremolite-actinolite or diopside-hedenbergite in skarn. The silicate minerals show varying growth patterns during the different phases of the tectonothermal evolution, with considerable static grain growth occurring between D1 and D2, and even after D2. F2 sheath folding along axes that plunge steeply to the SSE, parallel to a mineral stretching lineation and the dip direction of the S2 foliation, is suggested as a key deformation mechanism forming steeply plunging, cone- to rod-shaped mineralized bodies. This contrasts with a previous structural model invoking fold interference. A major shear zone with talc-chlorite-(quartz-biotite) mineral association separates the northern and southern structural domains at the deposit and bounds the polymetallic massive sulphides to the north.

  3. Temperature dependence of critical currents and ac transport losses in (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} and YBa{sub 2}Cu{sub 3}O{sub y} tapes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guo Min [Center for Advanced Power Systems, Florida State University, Tallahassee, FL 32310 (United States); Knoll, D C [Center for Advanced Power Systems, Florida State University, Tallahassee, FL 32310 (United States); Nguyen, D N [Center for Advanced Power Systems, Florida State University, Tallahassee, FL 32310 (United States); Sastry, P V P S S [Center for Advanced Power Systems, Florida State University, Tallahassee, FL 32310 (United States); Schwartz, Justin [Center for Advanced Power Systems, Florida State University, Tallahassee, FL 32310 (United States)

    2007-06-15

    The critical currents and self-field ac losses of YBa{sub 2}Cu{sub 3}O{sub y} coated conductors and (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes were measured at several temperatures between 45 K and the respective critical temperature. The temperature dependence of ac losses was measured at 50 Hz using the lock-in method for a transport current. The frequency dependence of ac loss was measured at 55 K for transport current frequencies from 25 to 400 Hz. The results show that variation of ac transport loss as a function of normalized critical current is nearly the same at all temperatures in the measured temperature range for both YBa{sub 2}Cu{sub 3}O{sub y} and (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes. The temperature dependence of the loss factor, however, is different for (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} and YBa{sub 2}Cu{sub 3}O{sub y} tapes because of the ferromagnetic loss in the NiW-based coated conductor substrate. Similarities and differences in the temperature and frequency dependence of ac transport losses between (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} and YBa{sub 2}Cu{sub 3}O{sub y} tapes are discussed.

  4. Influence of SrF2 on the Formation, Microstructure and Critical Temperature of (Bi,Pb)2Sr2Ca2Cu3O10 Polycrystalline Samples

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Jensen, Annemette Hindhede; Huhtinen, H.;

    2015-01-01

    Bulk ceramic samples with Bi1.72Pb0.34Sr1.87Ca1.91Cu3.13O9.83−x F 2x (0.00 ≤ x ≤ 0.51) nominal compositions were synthesized by a solid-state route using SrF2 as a fluorine source. Notwithstanding of the stage, at which SrF2 was introduced into the precursor powders (prior to or after calcination...

  5. sup 119 Sn-Moessbauer study on the normal lattice vibration of superconducting Bi(Pb) sub 2 Sr sub 2 Ca sub 2 Cu sub 3 Sn sub 0. 015 O sub 10-y

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Tetsuaki; Takashima, Yoshimasa (Kyushu Univ., Fukuoka (Japan). Faculty of Science); Katada, Motomi; Miura, Norio; Deshimaru, Yuichi; Otani, Tetsuya; Yamazoe, Noboru; Matsumoto, Yasukuni

    1991-04-01

    The {sup 119}Sn-Moessbauer spectrum of superconducting Bi(Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}Sn{sub 0.015}O{sub 10-y} ceramic, having the T{sub c} of 108 K, consists of an intense doublet peak with the {delta} of 0.18 mmcenter dots{sup -1} and the {Delta} of 1.01 mmcenter dot s{sup -1} at room temperature. The {delta} and {Delta} indicate that the Sn{sup 4+} is substituted for the copper ion in the triangular CuO{sub 3} site of the CuO{sub 4} layer. The {delta} and the absorption area increase gradually with decreasing temperature and become saturated at about 30 K, being consistent with the theoretical curves obtained from the 'combined Debye and Einstein model'. Only the normal vibration without the softening is observed in the CuO{sub 4} layer. (author).

  6. Processamento e caracterizações estruturais, microestruturais e ferroelétricas do composto magnetoelétrico BiFeO3-PbTiO3 obtido pelo método de Pechini

    Directory of Open Access Journals (Sweden)

    V. F. Freitas

    Full Text Available Resumo Neste trabalho uma rota alternativa de síntese, o método de Pechini modificado, foi utilizada para obter nanopartículas do composto BiFeO3-PbTiO3 (BFPT. As imagens obtidas por microscopia eletrônica de varredura revelaram tamanhos de partículas inferiores a 120 nm. Análises estruturais apontaram a organização estrutural do composto (formação de estruturas com simetria tetragonal como função da temperatura de síntese. Cálculos da polarização espontânea indicaram a intensidade alcançada no composto BFPT. As análises de densidade eletrônica obtidas pelo método da máxima entropia indicaram a configuração das ligações químicas presentes no composto.

  7. Preparation and physical properties of polycrystalline (Bi{sub 1{minus}x}Pb{sub x}){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} high {Tc} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Awan, M.S.; Maqsood, M.; Mirza, S.A.; Yousaf, M.; Maqsood, A. [Quaid-i-Azam Univ., Islamabad (Pakistan)

    1995-02-01

    (Bi{sub 1{minus}x}Pb{sub x}){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} (x = 0.3) high critical transition temperature ({Tc}) superconductors are synthesized by the solid-state reaction method in polycrystalline form. X-ray diffraction (XRD) studies, direct current (dc) electrical resistivity measurements, scanning electron microscopic (SEM) studies, critical current density measurements and zero-field alternating current (ac) susceptibility measurements are performed to investigate the physical changes, structural changes, and magnetic behavior of the superconducting samples. X-ray diffraction studies show that a high {Tc} phase exists with orthorhombic symmetry in the specimen. According to the XRD data, the lattice parameters of the high {Tc} phase were determined as a = 0.537(1) nm, b = 0.539(1) nm, and c = 3.70(1) nm. The compound exhibits a superconducting transition at 106 {plus_minus} 1 K for zero resistance. The ac susceptibility measurements in zero field confirm the dc electrical resistivity results; hence both support the XRD results. The particle size and structural changes as a function of the cold-pressing and aging effect are also reported.

  8. Effect of La-substitution on structural, dielectric and electrical properties of (Bi0.5Pb0.5) (Fe0.5Zr0.25Ti0.25)O3

    Science.gov (United States)

    Panda, Niranjan; Pattanayak, Samita; Choudhary, R. N. P.; Kumar, Ashok

    2016-09-01

    As lead zirconium titanate and bismuth ferrite (BFO), members of perovskite family, have high dielectric constant and ferroelectric/ferromagnetic phase transition temperature, they are used for many potential applications including random access memory, sensors. The present work describes the modifications in the ferroelectric behaviour of PZT doped BFO due to substitution of few molar percent of La on Fe-site. A thorough comparative investigation of the frequency and temperature response of dielectric permittivity, dielectric loss, electric modulus, complex impedance and ferroelectric properties of Bi0.5Pb0.5 [Fe(0.5- x) La x (Zr0.25Ti0.25)] O3, where x = 0.0, 0.1, 0.2, 0.3 (hence forth called as BFPZLTO) compounds were studied in a wide frequency range 10 kHz to 1 MHz at temperature range 25-400 °C using ac impedance spectroscopy and electric modulus analysis. The structural analysis of compound revealed the tetragonal phase with space group P4 mm at room temperature. Cole-Cole plots are used for interpretation of relaxation mechanism in the materials. The materials especially the compound with x = 0.3 found more suitable to be used in transducers, RAMs, flip-flop memories, etc., for electronics applications.

  9. The study of the dependency of critical current density on cross section of sample in Bi1.6Pb0.4Sr2Ca2Cu3Oy and YBa2Cu3O7-& delta ceramic superconductors

    Directory of Open Access Journals (Sweden)

    M Zargar Shoushtari

    2006-09-01

    Full Text Available  In this paper, the effect of the cross-section on the critical current density (Jc of a sample in ceramic superconductors YBa2Cu3O7-­δ (YBCO and Bi1.6Pb0.4Sr2Ca2cu3Oy (BPSCCO has been studied. Five orthorhombic bar samples of YBCO with cross-sections of 6.25, 7.67, 9.25, 11.76, 14.67 mm2­ and also five orthorhombic bar samples of BPSCCO with cross-section of 6.4, 9.01, 11.88, 13.86, 14.98 mm2­ with the same synthesis conditions by the solid state reaction method were prepared. After the preparation of the samples, the Meissner effect, the critical temperature (Tc, and the critical current density (Jc measurements, XRD and SEM have been done on the samples. The results of XRD show that the dominant phase in YBCO and BPSCCO are 123 and 2223, respectively. The results of Jc measurements in 77 K show that in both superconductors, the Jc decreases with increasing of cross-section (A. The type of dissipation obeys a power law with the relation . For a given cross-section, Jc of the BPSCCO sample is smaller than the YBCO sample.

  10. Investigation of luminescence and laser transition of Dy3+ ion in P2O5sbnd PbOsbnd Bi2O3sbnd R2O3 (R = Al, Ga, In) glasses

    Science.gov (United States)

    Ram, G. Chinna; Narendrudu, T.; Suresh, S.; Kumar, A. Suneel; Rao, M. V. Sambasiva; Kumar, V. Ravi; Rao, D. Krishna

    2017-04-01

    P2O5sbnd PbOsbnd Bi2O3sbnd R2O3 (R = Al, Ga, In) glasses doped with Dy2O3 were prepared by melt quenching technique. The prepared glasses were characterized by XRD, optical absorption, FTIR, luminescence studies. Judd-Ofelt parameters have been evaluated for three glass systems from optical absorption spectra and in turn radiative parameters for excited luminescent levels of Dy3+ ion are also calculated. Emission cross section and branching ratio values are observed to high for 6H13/2 level for Dy3+ ion. The yellow to blue intensity ratios and CIE chromaticity coordinates were calculated. Decay curves exhibit non exponential behavior. Quantum efficiency of prepared glasses was measured by using radiative and calculated life times. IR studies, J-O parameters and Y/B ratio values indicate that more asymmetry around Dy3+ ions in Ga2O3 mixed glass was observed. Chromaticity coordinates lie near ideal white light region. These coordinates and CCT values have revealed that all the prepared glasses emit quality white light especially the glasses mixed with Ga2O3 are suitable for development of white LEDs.

  11. The influence of nickel ions on spectroscopic and magnetic properties of PbO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} glass system

    Energy Technology Data Exchange (ETDEWEB)

    Satyanarayana, T; Rao, P Venkateswara; Rao, N Narasimha; Rambabu, M; Kumar, V Ravi, E-mail: vrksurya@rediffmail.com [Department of Physics, Acharya Nagarjuna University Nuzvid Campus - 521 201, A.P. (India)

    2009-07-15

    PbO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses mixed with different concentrations of NiO (ranging from 0 to 2.0 mol %) have been prepared by melt quenching technique and their spectroscopic properties viz., optical absorption and infrared transmission have been investigated. The optical absorption spectra of these glasses indicated that Ni{sup 2+} ions exist both in octahedral and tetrahedral sites. The IR spectral studies have revealed that the glasses containing NiO beyond 1.0 mol %, nickel ions mostly occupy octahedral positions, act as modifiers and induce higher degree of disorder in the glass network. The magnetic susceptibility studies indicated that a gradual decrease of the effective magnetic moment from 4.21 {mu}{sub B} (for sample N{sub 10}) to 2.91 {mu}{sub B} (for sample N{sub 20}); from this result, it is concluded that there is a gradual transformation of Ni{sup 2+} ions from the tetrahedral sites to the octahedral sites as the concentration of NiO is increased beyond 1.0 mol %.

  12. Magnetic field effect on Fe-induced short-range magnetic correlation and electrical conductivity in Bi1.75Pb0.35Sr1.90Cu0.91Fe0.09O6+y

    Energy Technology Data Exchange (ETDEWEB)

    Wakimoto, S [Japan Atomic Energy Agency (JAEA); Hiraka, Haruhiro [Institute for Materials Research, Tohoku University, Sendai, Japan; Kudo, Kazutaka [Institute for Materials Research, Tohoku University, Sendai, Japan; Okamoto, Daichi [Institute for Materials Research, Tohoku University, Sendai, Japan; Nishizaki, Terukazu [Institute for Materials Research, Tohoku University, Sendai, Japan; Kakurai, Kazuhisa [Japan Atomic Energy Agency (JAEA); Hong, Tao [ORNL; Zheludev, Andrey [Laboratory for Neutron Scattering ETHZ & PSI; Tranquada, John M. [Brookhaven National Laboratory (BNL); Kobayashi, Norio [Institute for Materials Research, Tohoku University, Sendai, Japan; Yamada, Kazuyoshi [Institute for Materials Research, Tohoku University, Sendai, Japan

    2010-08-01

    We report electrical-resistivity measurements and neutron-diffraction studies under magnetic fields of Bi{sub 1.75}Pb{sub 0.35}Sr{sub 1.90}Cu{sub 0.91}Fe{sub 0.09}O{sub 6+y}, in which hole carriers are overdoped. This compound shows short-range incommensurate magnetic correlation with incommensurability {delta} = 0.21, whereas a Fe-free compound shows no magnetic correlation. Resistivity shows an up turn at low temperature in the form of ln(1/T) and shows no superconductivity. We observe reduction in resistivity by applying magnetic fields (i.e., a negative magnetoresistive effect) at temperatures below the onset of short-range magnetic correlation. Application of magnetic fields also suppresses the Fe-induced incommensurate magnetic correlation. We compare and contrast these observations with two different models: (1) stripe order and (2) dilute magnetic moments in a metallic alloy with associated Kondo behavior. The latter picture appears to be more relevant to the present results.

  13. Ferroelectricity in the glassy material of the composition Bi{sub 2}O{sub 3}-Pb{sub 3}O{sub 4}-CuO-K{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Bahgat, A.A., E-mail: alaabahgat@hotmail.co [Department of Physics, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo (Egypt); Makram, B.A.A.; Shaisha, E.E. [Department of Physics, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo (Egypt); El-Desoky, M.M. [Department of Physics, Faculty of Education, Suze Canal University, El-Arish (Egypt)

    2010-09-10

    Glass sample of the composition 31.4 Bi{sub 2}O{sub 3}-2.33 Pb{sub 3}O{sub 4}-64.53 CuO-1.74 K{sub 2}O in mol% was prepared by the conventional quenching melt technique. The as-quenched single phase glass shows interesting ferroelectric properties which is not known in the field of glass science. If the as-quenched glass is heat treated above the glass transition temperature all signs of ferroelectricity disappears completely. X-ray diffraction and transmission electron microscopy as well as differential thermal analysis were used to recognize the glassy nature of the as-quenched sample. Ac dielectric measurements were performed as a function of temperature and frequency and showing ferroelectric to paraelectric phase transition at Curie's temperature of 540 K. Non-linear polarization as a function of temperature and applied electric field as well as pyroelectricity were also studied. The conduction mechanism was confirmed to obey the adiabatic small polaron hopping (SPH) and was mainly due to electronic transport between Cu ions. The dominant factor determining conductivity was the hopping carrier mobility in this glass. From the best fits, reasonable values of various SPH and VRH parameters are obtained.

  14. Multilayer thin films with compositional PbZr0.52Ti0.48O3/Bi1.5Zn1.0Nb1.5O7 layers for tunable applications.

    Science.gov (United States)

    Yu, Shihui; Li, Lingxia; Zhang, Weifeng; Sun, Zheng; Dong, Helei

    2015-05-11

    The dielectric properties and tunability of multilayer thin films with compositional PbZr0.52Ti0.48O3/Bi1.5Zn1.0Nb1.5O7 (PZT/BZN) layers (PPBLs) fabricated by pulsed laser deposition on Pt/TiO2/SiO2/Si substrate have been investigated. Dielectric measurements indicate that the PZT/BZN bilayer thin films exhibit medium dielectric constant of about 490, low loss tangent of 0.017, and superior tunable dielectric properties (tunability=49.7% at 500 kV/cm) at a PZT/BZN thickness ratio of 3, while the largest figure of merit is obtained as 51.8. The thickness effect is discussed with a series connection model of bilayer capacitors, and the calculated dielectric constant and loss tangent are obtained. Furthermore, five kinds of thin-film samples comprising single bilayers, two, three, four and five PPBLs were also elaborated with the final same thickness. The four PPBLs show the largest dielectric constant of ~538 and tunability of 53.3% at a maximum applied bias field of 500 kV/cm and the lowest loss tangent of ~0.015, while the largest figure of merit is 65.6. The results indicate that four PPBLs are excellent candidates for applications of tunable devices.

  15. In-plane polarization dependence of (Bi,Pb){sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} single crystals studied by X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ghafari, A., E-mail: ghafari@physik.hu-berlin.de [Institute of Physics, Humboldt University of Berlin, Newtonstr., 15, D-12489 Berlin (Germany); Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, I-34149 Trieste (Italy); Ariffin, A.K. [Institute of Physics, Humboldt University of Berlin, Newtonstr., 15, D-12489 Berlin (Germany); Department of Physics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim (Malaysia); Janowitz, C., E-mail: christoph.janowitz@physik.hu-berlin.de [Institute of Physics, Humboldt University of Berlin, Newtonstr., 15, D-12489 Berlin (Germany); Dwelk, H.; Krapf, A.; Manzke, R. [Institute of Physics, Humboldt University of Berlin, Newtonstr., 15, D-12489 Berlin (Germany)

    2014-06-15

    The effects of in-plane polarization change on the determination of the hole density of weakly under-doped (Bi, Pb)-2212 single crystals has been studied by x-ray absorption spectroscopy (XAS). The XAS signal at the CuL{sub 3} edge (925–940 eV) and O K edge (525 eV to 539 eV) were recorded under continuous rotation of the CuO{sub 2} plane from 0° to 180° with a minimum increment of 1.8°, yielding experimentally an in-plane polarization dependence for the absorption signals at the respective threshold. From that the in-plane angular dependence of the hole density (n{sub H}(φ)) could be determined. Fermi's golden rule was then used for the evaluation of the in-plane polarization dependence showing the expected polarization independence in disaccord to the experimental observations. Possible scenarios to solve this issue are discussed. Our results propose that polarization dependence could be due to inhomogeneous distribution of holes in the CuO{sub 2} planes which is also supported by models. Second, the role of out of plane orbitals has to be taken into account for interpretation.

  16. Critical currents of superconducting BiPbSrCaCuO tapes in the magnetic flux density range 0--19. 75 T at 4. 2, 15, and 20 K

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K.; Hikata, T. (Osaka Research Laboratories, Sumitomo Electric Industries, Osaka (Japan)); Iwasa, Y. (Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA (USA))

    1990-10-29

    Critical currents of superconducting silver-sheathed tapes of Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2}Ca{sub 2.2}Cu{sub 3}O{sub {ital x}} have been measured in the magnetic flux density range 0--19.75 T at 4.2, 15, and 20 K. One tape achieved a critical current of 60.6 A at 19.75 T and 20 K; the corresponding critical current density is 551 A/mm{sup 2}. In the same field, the tape has critical currents of 72.3 A (657 A/mm{sup 2}) at 15 K and 94.2 A (856 A/mm{sup 2}) at 4.2 K. At 77 K and in zero field, the tape carries 32.9 A (299 A/mm{sup 2}). These results indicate that high {ital T}{sub {ital c}}'' superconducting magnets of engineering interest may soon be feasible.

  17. Piezoresponse and magnetic properties of multiferroic (1−x)Bi{sub 0.9}Dy{sub 0.1}FeO{sub 3}–xPbTiO{sub 3} solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Jian [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049 (China); Department of Chemistry and 4D LABS, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Wu, Hua [Department of Applied Physics, Donghua University, Ren Min Road 2999, Songjiang, 201620 Shanghai (China); Department of Chemistry and 4D LABS, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Ren, Wei, E-mail: wren@mail.xjtu.edu.cn, E-mail: zye@sfu.ca [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049 (China); Ye, Zuo-Guang, E-mail: wren@mail.xjtu.edu.cn, E-mail: zye@sfu.ca [Department of Chemistry and 4D LABS, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049 (China)

    2015-08-21

    The multiferroic solid solution of (1−x)[0.9BiFeO{sub 3}–0.1DyFeO{sub 3}]–xPbTiO{sub 3} with compositions around the morphotropic phase boundary has been synthesized in the form of ceramics and characterized by Piezoresponse Force Microscope (PFM) and Superconducting Quantum Interference Device. Both the original local polar domain structure and the domain evolution after poling have been studied by PFM. The PFM phase imaging has revealed some interesting details of poling and domain switching process: The out-of-plane phase image shows a uniform direction of polarization along the applied electric field, while the in-plane phase image indicates two kinds of domains with antiparallel polarizations. This kind of poled domain structure is explained based on the orientations of the polarization as permitted by the rhombohedral crystal symmetry in grains of different crystallographic orientations. The magnetic properties measured within the temperature range from 1.8 K to 300 K reveal an interesting sequence of magnetic transitions from a weakly ferromagnetic order (WFM{sub 1}) to an antiferromagnetic state (AFM), and then to another weak ferromagnetic phase (WFM{sub 2}), upon cooling. A preliminary magnetic phase diagram is proposed for BDF-34PT.

  18. Field Dependence of Magnetization and dM/dH for Sm- and Gd-Doped Bi1.7Pb0.3Sr2Ca2-xRExCu3O10+y Compounds

    Institute of Scientific and Technical Information of China (English)

    Atilla COSKUN; Ahmet EKICIBIL; Bekir OZCELIK; Kerim KIYMAC

    2004-01-01

    We have performed magnetization measurements as a function of magnetic fields up to 4kOe on Bi1.7Pb0.3Sr2Ca2-xRExCu3O10+y (RE: Gd0.01, Sm0.03), at different fixed temperatures T < Tc in the range 15 ≤ T ≤ 75K.We have observed three important features. Firstly, the M-H curves of both the Sm- and Gd-doped samples are similar and each shows a minimum of M at a certain critical field Hc, above which there appears to be a monotonic decrease in magnitude. Secondly, the magnitude of the initial susceptibility dM/dH, related to the superconducting volume, decreases with increasing temperature. In other words, the decrease of |dM/dH| with T indicates that the superconducting regions reduce in size and the paramagnetic domains probably grow at the expense of superconductivity. The third feature is the fast decrease of hysteresis loops in both the Gd and Sm doped samples with increasing temperature, which implies existence of flux pinning centres. Thus the results show that the Ca2+ →Sm3+ and Gd3+ substitution decreases the hole carrier concentration and hence the volume fraction of the superconducting phase.

  19. Concentration effect of Sm{sup 3+} ions in B{sub 2}O{sub 3}–PbO–PbF{sub 2}–Bi{sub 2}O{sub 3}–ZnO glasses – Structural and luminescence investigations

    Energy Technology Data Exchange (ETDEWEB)

    Arunkumar, S.; Marimuthu, K., E-mail: mari_ram2000@yahoo.com

    2013-07-15

    Graphical abstract: -- Highlights: •δ and revel the ionic nature and the Same decreases with Sm{sup 3+} ion content. •Higher Ω{sub 4} revels the higher rigidity and higher covalency around the Sm{sup 3+} ion site. •τ{sub exp} decreases with increase in Sm{sup 3+} ion due to energy transfer between Sm{sup 3+} ions. •Energy transfer between the Sm{sup 3+}–Sm{sup 3+} ion site is due to dipole–dipole interaction. •0.5SmPbFB glass possesses higher A, β{sub R} and xτ{sub R}, potential for laser applications. -- Abstract: Concentration dependent spectroscopic properties of Sm{sup 3+} ions are investigated in the prepared xSm:PbFB lead fluorobororate glasses with the composition (40 − x)B{sub 2}O{sub 3} + 20PbO + 16PbF{sub 2} + 12Bi{sub 2}O{sub 3} + 12ZnO + xSm{sub 2}O{sub 3} (where x = 0.05, 0.1, 0.5, 1, 2 and 3 wt.%). Surface morphological analysis and structural behaviors of the prepared glasses have been explored through SEM, EDX, XRD, FTIR and Raman spectral analysis. The amorphous nature of the prepared glasses have been confirmed through XRD spectral analysis. The presence of BO{sub 3}, BO{sub 4}, B–O–B and Pb/Bi–O–B vibrational stretching units in the prepared glasses are confirmed through FTIR and Raman spectral analysis. The optical characterizations were carried out using UV–vis–NIR absorption, luminescence spectra and decay curves of the present glasses. The calculated bonding parameter (β{sup ¯} and δ) values reveal the ionic nature of the Sm–O bond in the prepared glasses. The Judd–Ofelt intensity parameters, Ω{sub λ}, were evaluated from the measured oscillator strength of the various absorption bands to study the bonding environment around the Sm{sup 3+} ions in the prepared glasses. From the JO intensity parameters and emission spectral measurements, the radiative properties such as stimulated emission cross-section (σ{sub P}{sup E}), branching ratio (β{sub R}) and radiative lifetime (τ{sub R}) for the {sup 6}H

  20. Genetic Pd, Pt, Au, Ag, and Rh mineralogy in Noril'sk sulfide ores

    Science.gov (United States)

    Spiridonov, E. M.; Kulagov, E. A.; Serova, A. A.; Kulikova, I. M.; Korotaeva, N. N.; Sereda, E. V.; Tushentsova, I. N.; Belyakov, S. N.; Zhukov, N. N.

    2015-09-01

    The undeformed ore-bearing intrusions of the Noril'sk ore field (NOF) cut through volcanic rocks of the Late Permian-Early Triassic trap association folded in brachysynclines. Due to the nonuniform load on the roof of intrusive bodies, most sulfide melts were squeezed, up to the tops of ore-bearing intrusions; readily fusible Ni-Fe-Cu sulfide melts were almost completely squeezed. In our opinion, not only one but two stages of mineralization developed at the Noril'sk deposits: (i) syntrap magmatic and (ii) epigenetic post-trap metamorphic-hydrothermal. All platinum-group minerals (PGM) and minerals of gold are metasomatic in the Noril'sk ores. They replaced sulfide solid solutions and exsolution structures. All types of PGM and Au minerals occur in the ores, varying in composition from pyrrhotite to chalcopyrite, talnakhite, mooihoekite, and rich in galena; they are localized in the inner and outer contact zones and differ only in the quantitative proportions of ore minerals. The aureoles of PGM and Au-Ag minerals are wider than the contours of sulfide bodies and coincide with halos of fluid impact on orebodies and adjacent host rocks. The pneumatolytic PGM and Au-Ag minerals are correlated in abundance with the dimensions of sulfide bodies. Their amounts are maximal in veins of late fusible ore composed of eutectic PbS ss and iss intergrowths, as well as at their contacts. The Pd and Pt contents in eutectic sulfide ores of NOF are the world's highest. In the process of noble-metal mineral formation, the fluids supply Pd, Pt, Au, As, Sb, Sn, Bi, and a part of Te, whereas Fe, Ni, Cu, Pb, Ag, Rh, a part of Te and Pd are leached from the replaced sulfide minerals. The pneumatolytic PGM of the early stage comprises Pd and Pt intermetallic compounds enriched in Au along with Pd-Pt-Fe-Ni-Cu-Sn-Pb(As) and (Pd,Pt,Au)(Sn,Sb,Bi,Te,As) solid solutions. Pneumatolytic PGM and Au minerals of the middle stage are products of solid-phase transformation and recrystallization of

  1. Fluid sources and metallogenesis in the Blackbird Co-Cu-Au-Bi-Y-REE district, Idaho, U.S.A.: Insights from major-element and boron isotopic compositions of tourmaline

    Science.gov (United States)

    Trumbull, R.B.; Slack, J.F.; Krienitz, M.-S.; Belkin, H.E.; Wiedenbeck, M.

    2011-01-01

    Tourmaline is a widespread mineral in the Mesoproterozoic Blackbird Co-Cu-Au-Bi-Y-REE district, Idaho, where it occurs in both mineralized zones and wallrocks. We report here major-element and B-isotope compositions of tourmaline from stratabound sulfide deposits and their metasedimentary wallrocks, from mineralized and barren pipes of tourmaline breccia, from late barren quartz veins, and from Mesoproterozoic granite. The tourmalines are aluminous, intermediate in the schorl-dravite series, with Fe/(Fe + Mg) values of 0.30 to 0.85, and 10 to 50% X-site vacancies. Compositional zoning is prominent only in tourmaline from breccias and quartz veins; crystal rims are enriched in Mg, Ca and Ti, and depleted in Fe and Al relative to cores. The chemical composition of tourmaline does not correlate with the presence or absence of mineralization. The ??11B values fall into two groups. Isotopically light tourmaline (-21.7 to-7.6%o) occurs in unmineralized samples from wallrocks, late quartz veins and Mesoproterozoic granite, whereas heavy tourmaline (-6.9 to +3.2%o) is spatially associated with mineralization (stratabound and breccia-hosted), and is also found in barren breccia. At an inferred temperature of 300??C, boron in the hydrothermal fluid associated with mineralization had ??11B values of-3 to +7%o. The high end of this range indicates a marine source of the boron. A likely scenario involves leaching of boron principally from marine carbonate beds or B-bearing evaporites in Mesoproterozoic strata of the region. The ??11B values of the isotopically light tourmaline in the sulfide deposits are attributed to recrystallization during Cretaceous metamorphism, superimposed on a light boron component derived from footwall siliciclastic sediments (e.g., marine clays) during Mesoproterozoic mineralization, and possibly a minor component of light boron from a magmatic-hydrothermal fluid. The metal association of Bi-Be-Y-REE in the Blackbird ores suggests some magmatic input

  2. Interfacial charge-induced polarization switching in Al{sub 2}O{sub 3}/Pb(Zr,Ti)O{sub 3} bi-layer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Jin; Park, Min Hyuk; Jeon, Woojin; Kim, Han Joon; Moon, Taehwan; Lee, Young Hwan; Kim, Keum Do; Hyun, Seung Dam; Hwang, Cheol Seong, E-mail: cheolsh@snu.ac.kr [Department of Materials Science & Engineering and Inter-University Semiconductor Research Center, College of Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2015-12-14

    Detailed polarization switching behavior of an Al{sub 2}O{sub 3}/Pb(Zr,Ti)O{sub 3} (AO/PZT) structure is examined by comparing the phenomenological thermodynamic model to the experimental polarization–voltage (P-V) results. Amorphous AO films with various thicknesses (2–10 nm) were deposited on the polycrystalline 150-nm-thick PZT film. The thermodynamic calculation showed that the transition from the ferroelectric-like state to the paraelectric-like state with increasing AO thickness occurs at ∼3 nm thickness. This paraelectric-like state should have exhibited a negative capacitance effect without permanent polarization switching if no other adverse effects are involved. However, experiments showed typical ferroelectric-like hysteresis loops where the coercive voltage increased with the increasing AO thickness, which could be explained by the carrier injection through the thin AO layer and trapping of the carriers at the AO/PZT interface. The fitting of the experimental P-V loops using the thermodynamic model considering the depolarization energy effect showed that trapped charge density was ∼±0.1 Cm{sup −2} and critical electric field at the Pt electrode/AO interface, at which the carrier transport occurs, was ∼±10 MV/cm irrespective of the AO thickness. Energy band model at each electrostatic state along the P-V loop was provided to elucidate correlation between macroscopic polarization and internal charge state of the stacked films.

  3. Screening on binary Zr-1X (X = Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi) alloys with good in vitro cytocompatibility and magnetic resonance imaging compatibility.

    Science.gov (United States)

    Zhou, F Y; Qiu, K J; Li, H F; Huang, T; Wang, B L; Li, L; Zheng, Y F

    2013-12-01

    In this study, the microstructures, mechanical properties, corrosion behaviors, in vitro cytocompatibility and magnetic susceptibility of Zr-1X alloys with various alloying elements, including Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi, were systematically investigated to explore their potential use in biomedical applications. The experimental results indicated that annealed Zr-1X alloys consisted entirely or primarily of α phase. The alloying elements significantly increased the strength and hardness of pure Zr and had a relatively slight influence on elastic modulus. Ru was the most effective enhancing element and Zr-1Ru alloy had the largest elongation. The results of electrochemical corrosion indicated that adding various elements to Zr improved its corrosion resistance, as indicated by the reduced corrosion current density. The extracts of the studied Zr-1X alloys produced no significant deleterious effects on osteoblast-like cells (MG 63), indicating good in vitro cytocompatibility. All except for Zr-1Ag alloy showed decreased magnetic susceptibility compared to pure Zr, and Zr-1Ru alloy had the lowest magnetic susceptibility value, being comparable to that of α' phase Zr-Mo alloy and Zr-Nb alloy and far lower than that of Co-Cr alloy and Ti-6Al-4V alloy. Among the experimental Zr-1X alloys, Zr-1Ru alloy possessing high strength coupled with good ductility, good in vitro cytocompatibility and low magnetic susceptibility may be a good candidate alloy for medical devices within a magnetic resonance imaging environment. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Constraints on the timing of Co-Cu ± Au mineralization in the Blackbird district, Idaho, using SHRIMP U-Pb ages of monazite and xenotime plus zircon ages of related Mesoproterozoic orthogneisses and metasedimentary rocks

    Science.gov (United States)

    Aleinikoff, John N.; Slack, John F.; Lund, Karen; Evans, Karl V.; Fanning, C. Mark; Mazdab, Frank K.; Wooden, Joseph L.; Pillers, Renee M.

    2012-01-01

    The Blackbird district, east-central Idaho, contains the largest known Co reserves in the United States. The origin of strata-hosted Co-Cu ± Au mineralization at Blackbird has been a matter of controversy for decades. In order to differentiate among possible genetic models for the deposits, including various combinations of volcanic, sedimentary, magmatic, and metamorphic processes, we used U-Pb geochronology of xenotime, monazite, and zircon to establish time constraints for ore formation. New age data reported here were obtained using sensitive high resolution ion microprobe (SHRIMP) microanalysis of (1) detrital zircons from a sample of Mesoproterozoic siliciclastic metasedimentary country rock in the Blackbird district, (2) igneous zircons from Mesoproterozoic intrusions, and (3) xenotime and monazite from the Merle and Sunshine prospects at Blackbird. Detrital zircon from metasandstone of the biotite phyllite-schist unit has ages mostly in the range of 1900 to 1600 Ma, plus a few Neoarchean and Paleoproterozoic grains. Age data for the six youngest grains form a coherent group at 1409 ± 10 Ma, regarded as the maximum age of deposition of metasedimentary country rocks of the central structural domain. Igneous zircons from nine samples of megacrystic granite, granite augen gneiss, and granodiorite augen gneiss that crop out north and east of the Blackbird district yield ages between 1383 ± 4 and 1359 ± 7 Ma. Emplacement of the Big Deer Creek megacrystic granite (1377 ± 4 Ma), structurally juxtaposed with host rocks in the Late Cretaceous ca. 5 km north of Blackbird, may have been involved in initial deposition of rare earth elements (REE) minerals and, possibly, sulfides. In situ SHRIMP ages of xenotime and monazite in Co-rich samples from the Merle and Sunshine prospects, plus backscattered electron imagery and SHRIMP analyses of trace elements, indicate a complex sequence of Mesoproterozoic and Cretaceous events. On the basis of textural relationships

  5. Effect of Au film pre-deposited at different durations as inner electrode on the electrical properties and interface microstructures of Na2O-PbO-Nb2O5-SiO2 multi-layer glass-ceramic capacitors

    Institute of Scientific and Technical Information of China (English)

    Jun ZHU; Jun LUO; Qingmeng ZHANG; Jun DU

    2011-01-01

    To further study the effect of sputtered Au film as transition electrode layer on the electrical properties and interface microstructures of Na2O-PbO-Nb2O5-SiO2 multilayer glass-ceramic capacitors,Au films pre-deposited at different time were prepared by DC magnetron sputtering.Compared with the single paste electrode structure,samples with Au films pre-deposited from 6 to 18 min have the consistent performance to effectively improve the electrical properties of the capacitors,resulting in the doubled breakdown strength,an increase of equivalent capacitance by 22% and a decrease of leakage current by an order of magnitude.SEM observations indicate that the Au films with deposition time from 6 to 18 min would all help the formation of a dense electrode/dielectric interface and inhibit the diffusion of Ag.The results reveal that Au film pre-deposited for 6 min as inner electrode was sufficient to improve the interface microstructure and therefore to inhibit the Ag diffusion and enhance the overall performance of the multi-layer glass-ceramic capacitors.

  6. Investigation on structural, Mössbauer and ferroelectric properties of (1-x)PbFe0.5Nb0.5O3-(x)BiFeO3 solid solution

    Science.gov (United States)

    Dadami, Sunanda T.; Matteppanavar, Shidaling; Shivaraja, I.; Rayaprol, Sudhindra; Angadi, Basavaraj; Sahoo, Balaram

    2016-11-01

    In this study, (1-x)PbFe0.5Nb0.5O3(PFN)-(x)BiFeO3(BFO) multiferroic solid solutions with x=0.0, 0.1, 0.2, 0.3 and 0.4 were synthesized through single step solid state reaction method and characterized thoroughly through X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FTIR), Raman, Mössbauer spectroscopy and ferroelectric studies. The room temperature (RT) XRD studies confirmed the formation of single phase with negligible amount of secondary phases (x=0.2 and 0.4). The zoomed XRD patterns of (1-x)PFN-(x)BFO solid solutions showed the clear structural phase transition from monoclinic (Cm) to rhombohedral (R3c) at x=0.4. The Raman spectra of the (1-x)PFN-(x)BFO solid solutions showed the composition dependent phase transition from monoclinic (Cm) to rhombohedral (R3c). With increasing x in PFN, the modes related monoclinic symmetry changes to those of rhombohedral symmetry. The RT Mössbauer spectroscopy results evidenced the existence of composition dependent phase transition from paramagnetic to weak antiferromagnetic ordering and weak antiferromagnetic to antiferromagnetic ordering. The Mössbauer spectroscopy showed paramagnetic behavior with a doublet for x=0.0, 0.1 and 0.2 are shows the weak antiferromagnetic with paramagnetic ordering. For x=0.3 and 0.4 shows the sextet pattern and it is a clear evidence of antiferromagnetism. The ferroelectric (P-E) loops at RT indicate the presence of small polarization, as the x concentration increases in PFN, the remnant polarization and coercive field were decreased, which may due to the increase in the conductivity and leaky behavior of the samples.

  7. Pb II

    African Journals Online (AJOL)

    Windows User

    ISSN 1684–5315 ©2012 Academic Journals ... Exposure to Pb above permissible limit (50 ppb in water) .... taken and analyzed for residual metal concentration determination. ..... loss in Pb(II) sorption capacity up to five cycles of reuse of.

  8. Spectroscopy of exotic nuclei with A {approx} 190: single particle states and collective properties of {sup 187,189}Bi and {sup 188}Pb; Spectroscopie de noyaux exotiques dans la region de masse A {approx} 190: la structure des isotopes {sup 187,189}Bi et {sup 188}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Huerstel, A

    2002-11-01

    This thesis is devoted to the study of very neutron deficient nuclei in the lead region of the nuclear chart and more precisely to the investigation of the single particle states and collective properties of the {sup 187,189}Bi isotopes by gamma-ray spectroscopy. These nuclei were produced via fusion-evaporation reaction induced by a krypton beam on a silver target. In this mass region, the cross section for producing these nuclei are very low, of the order of a few micro-barns, making experimental studies very difficult. The identification of the nuclei was done using the very powerful RDT (Recoil Decay Tagging) technique, based on the selection of the isotopes through their characteristic alpha-particle decays. The experiments were performed at the university of Jyvdskyla (Finland) with the facility combining the gamma-ray spectrometer JUROSPHERE and the magnetic gas-filled separator RITU. Isomeric states were observed in both nuclei and their life-times measured. The systematics of individual proton states in odd-mass bismuth isotopes have been reproduced with a shell model up to 20 neutrons away from the valley of stability. Furthermore, rotational bands, a signature of collective nuclear motion, have been established for the first time in these nuclei. The interpretation of these results led to the conclusion that {sup 187,189}Bi have a prolate shape at low excitation energy, unlike the heavier bismuth isotopes which have been interpreted to have oblate deformation, implying a shape transition in this mass region. Hartree-Fock-Bogolyubov calculations are consistent with the experimental indication of shape coexistence, as seen in the neighbouring even-even lead nuclei. (author)

  9. Mesoarchean (3.0 and 2.86 Ga) host rocks of the iron oxide-Cu-Au Bacaba deposit, Carajás Mineral Province: U-Pb geochronology and metallogenetic implications

    Science.gov (United States)

    Moreto, Carolina Penteado Natividade; Monteiro, Lena V. S.; Xavier, Roberto P.; Amaral, Wagner S.; Dos Santos, Ticiano José S.; Juliani, Caetano; de Souza Filho, Carlos Roberto

    2011-10-01

    The Bacaba iron oxide-copper-gold deposit, situated within a WNW-ESE-striking shear zone in the Carajás Domain, Carajás Mineral Province, is hosted by the Serra Dourada Granite, the Bacaba Tonalite, and crosscutting gabbro intrusions, which were intensely affected by sodic (albite-scapolite), potassic, chloritic, and hydrolytic hydrothermal alteration. This deposit is located 7 km northeast of the world-class Sossego iron oxide-copper-gold deposit and might represent a distal and deeper portion of the same or related hydrothermal system. The U-Pb laser ablation inductively coupled plasma-mass spectrometry data for zircon from a sodically altered sample of the Serra Dourada Granite yielded a 2,860±22 Ma (MSWD=11.5) age. Three samples from the Bacaba Tonalite, including one with potassic alteration and two with Cu-Au mineralization, rendered the 3,001.2±3.6 Ma (MSWD=1.8), 2,990.9±5.8 Ma (MSWD=1.9), and 3,004.6±9 Ma (MSWD=2.2) ages, respectively. The ca. 2.86 and ca. 3.0 Ga ages are interpreted as the timing of the igneous crystallization of the Serra Dourada Granite and the Bacaba Tonalite, respectively, and represent the oldest magmatic events recognized in the Carajás Domain. The Serra Dourada Granite and the Bacaba Tonalite are interpreted to greatly predate the genesis of the Bacaba deposit. A genetic link is improbable in the light of the similarities with the Sossego deposit, which is also hosted by younger ca. 2.76 Ga metavolcano-sedimentary units of the Itacaiúnas Supergroup. In this context, the iron oxide-copper-gold deposits in the southern sector of the Carajás Domain could be mainly controlled by important crustal discontinuities, such as a regional shear zone, rather than be associated with a particular rock type. These results expand the potential for occurrences of iron oxide-copper-gold deposits within the Mesoarchean basement rocks underlying the Carajás Basin, particularly those crosscut by Neoarchean shear zones.

  10. Microstructural and magneto-transport properties of Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 1−x}Gd{sub x}Cu{sub 2}O{sub 8+δ} superconducting ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Boudjadja, Y., E-mail: yazid.bouj@Gmail.com [NDT Laboratory, Faculty of Science and Technology, Jijel University, Jijel 18000 (Algeria); Amira, A.; Mahamdioua, N.; Saoudel, A. [NDT Laboratory, Faculty of Science and Technology, Jijel University, Jijel 18000 (Algeria); Menassel, S. [MSAR Unit, Physics Department, Constantine 1 University, Constantine 25017 (Algeria); Varilci, A.; Terzioglu, C.; Altintas, S.P. [Department of Physics, Faculty of Arts and Sciences, AIB University, Bolu 14280 (Turkey)

    2017-01-15

    This study aims to investigate the effect of Gd doping on the phase formation, microstructure, transport and magnetic properties of the Bi(Pb)-2212 system. A series of superconducting bulks with a nominal composition of Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 1−x}Gd{sub x}Cu{sub 2}O{sub 8+δ} with x=0, 0.05, 0.10 and 0.15 are synthesized by the solid state synthesis route. The formed samples are characterized by means of X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), electrical transport and magnetic measurements. The experiment results reveal that all the samples doped are composed of Bi-2212 phase and traces of Bi-2201 secondary phase when compared to the undoped sample. The refinement of cell parameters shows that the doping reduces the cell volume of the samples. The texture degree decreases with doping while the degree of orthorhombicity increases. Quantitative EDS analysis confirms that Gd atoms are successfully introduced into crystalline structure. The SEM micrographs show randomly distributed grains with a flake-like shape. The highest value of onset critical transition temperatures is obtained for x=0.10 and is about 90.22 K, which correlates well with the observed slope of resistivity and the hole concentration of the CuO{sub 2} layers. Magnetic hysteresis loops suggest that the diamagnetism, remanant magnetization and lower critical field are better for x=0.10. Based on the enhancements of both grain boundary weak-links and flux pinning centers, improvement of the critical current densities and flux pinning density is obtained with this kind of doping.

  11. Transport critical current density of (Bi{sub 1.6}Pb{sub 0.4})Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}/Ag superconductor tapes with addition of nanosized CoFe{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Hafiz, M.; Abd-Shukor, R. [Universiti Kebangsaan Malaysia, School of Applied Physics, Bangi, Selangor (Malaysia)

    2015-09-15

    The effect of nanosized CoFe{sub 2}O{sub 4} (60 nm) addition on the transport critical current density, J{sub c}, of (Bi{sub 1.6}Pb{sub 0.4})Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}(CoFe{sub 2}O{sub 4}){sub x} (x = 0-0.05 wt%) superconductor prepared by the co-precipitation method was investigated. The optimal J{sub c} (measured using the four-point probe method) was observed in the x = 0.01 wt% pellets. Using this optimal wt%, Ag-sheathed (Bi{sub 1.6}Pb{sub 0.4})Sr{sub 2}Ca{sub 2}Cu3O{sub 10}(CoFe{sub 2}O{sub 4}){sub 0.01} superconductor tapes were fabricated using the powder-in-tube method. The tapes were sintered for 50 and 100 h at 845 C. The phase and microstructure of the samples were determined using the powder X-ray diffraction method and scanning electron microscopy, respectively. The temperature dependence of J{sub c} for the tapes in various applied magnetic fields was also measured. J{sub c} of (Bi{sub 1.6}Pb{sub 0.4})Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}(CoFe{sub 2}O{sub 4}){sub 0.01}/Ag tapes sintered for 100 h was 22,420 A/cm{sup 2} at 30 K. The non-added tapes sintered for 100 h showed a much lower J{sub c} (8280 A/cm{sup 2} at 30 K). This study showed that addition of CoFe{sub 2}O{sub 4} nanoparticles enhanced the transport critical current density in the (Bi{sub 1.6}Pb{sub 0.4})Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} superconductor tapes. This result is consistent with the previous calculations on frozen flux superconductor in a nanomagnet-superconductor hybrid system. (orig.)

  12. Gd-substituted Bi-2223 superconductor

    Indian Academy of Sciences (India)

    D R Mishra

    2008-03-01

    The effects of gadolinium doping at calcium site on the normal and super-conducting properties of Bi-2223 system were studied. The Gd-doped (BiPb)-2223 series of specimens, namely Batch I, II and III were sintered at three different sintering temperatures 830, 850 and 895° C respectively. The properties investigated are (1) the normal state resistivity with a view to study metal-to-insulator transition, (2) the XRD patterns of the specimens with a view to study the relative composition of (BiPb)-2212 and (BiPb)-2223 phases and (3) the superconducting fluctuation behaviour (SFB) with a view to determine the effect of doping, if any, on the dimensionality of the fluctuation conductivity of the system. The normal state resistivity of Gd-substituted Bi-2223 specimens shows metallic, semiconducting and insulating behaviour. The c( = 0) values indicate that (BiPb)-2223 phase is responsible for the observed superconducting transitions in Batch I and Batch II specimens with Gd concentrations ≤ 0.7. This observation is further confirmed in the analysis of XRD patterns of these specimens. Gadolinium, being a magnetic impurity, has pair breaking effect near the Fermi level and decreases c( = 0). The analysis of the superconducting fluctuation behaviour (SFB) shows a 2D dimensionality without any cross-over.

  13. Inhomogeneous distribution of the intergranular pinning energy in polycrystalline Bi{sub 1.64}Pb{sub 0.36}Sr{sub 2}Ca{sub 2}Cu{sub 3}O {sub y} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Govea-Alcaide, E. [Departamento de Fisica, Universidad de Oriente, Patricio Lumumba s/n, P.O. Box 90500, Santiago de Cuba (Cuba); Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05315-970, S. Paulo, SP (Brazil); Hernandez-Wolpez, M. [Departamento de Fisica, Universidad de Camagueey, Crta. Circunvalacion Norte Km 5 1/2 s/n (Cuba); Batista-Leyva, A.J. [Superconductivity Laboratory, IMRE-Physics Faculty, University of Havana, 10400 Havana (Cuba); Department of General Physics and Mathematics, InSTEC, P.O. Box 6163, 10600 Havana (Cuba); Jardim, R.F. [Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05315-970, S. Paulo, SP (Brazil); Mune, P. [Departamento de Fisica, Universidad de Oriente, Patricio Lumumba s/n, P.O. Box 90500, Santiago de Cuba (Cuba)]. E-mail: mune@cnt.uo.edu.cu

    2005-06-15

    Measurements of the electrical resistivity as a function of temperature, {rho}(T), for different values of applied magnetic field, B {sub a} (0 B {sub a} 50 mT), were performed in samples extracted from different regions of the same Bi{sub 1.64}Pb{sub 0.36}Sr{sub 2}Ca{sub 2}Cu{sub 3}O {sub y} pellet in order to evaluate its homogeneity regarding the transport properties. Three pieces in form of slab were cut from the pellet. The first was extracted from the interface where the piston used in the compacting process has a direct mechanical contact with the powders (face A). The second, was taken from the interface parallel to the latter which is located in the base of the cylindrical sample (face B). Finally, the last piece was obtained by cutting an slab along the axis of the cylinder from the face A to face B. We have found appreciable differences in the grain orientation between these pieces by using X-ray diffractometry. Results indicate that the grains of the samples extracted from the interfaces A and B, are preferentially aligned with their c-axis parallel to the compacting direction. However, this feature is practically absent in the sample that was cut along the axis of the pellet, where the grains are more randomly oriented. The {rho}(T) dependence at zero applied magnetic field shows a similar metallic-like behavior in the normal-state region in all samples, but the electrical resistivity at 200 K of the samples extracted from the interfaces A and B is {approx}16% lower than the observed value for the other sample. In addition, the values of the so-called offset critical temperature, T {sub off}, show an appreciable decrease with increasing applied magnetic field, B {sub a}. In the case of the samples extracted from the faces A and B T {sub off} falls {approx}9%, while in the sample cut along the thickness of the pellets was {approx}13%. The above transport experimental results are interpreted in terms of changes in the grain alignment and the effective

  14. Composition and source of salinity of ore-bearing fluids in Cu-Au systems of the Carajás Mineral Province, Brazil

    Science.gov (United States)

    Xavier, Roberto; Rusk, Brian; Emsbo, Poul; Monteiro, Lena

    2009-01-01

    The composition and Cl/Br – NaCl ratios of highly saline aqueous inclusions from large tonnage (> 100 t) IOCG deposits (Sossego, Alvo 118, and Igarapé Bahia) and a Paleoproterozoic intrusion-related Cu-Au-(Mo-W-Bi-Sn) deposit (Breves; chromatography. In both Cu-Au systems, brine inclusions are Ca-dominated (5 to 10 times more than in porphyry Cu-Au fluids), and contain percent level concentrations of Na and K. IOCG inclusion fluids, however, contain higher Sr, Ba, Pb, and Zn concentrations, but significantly less Bi, than the intrusion-related Breves inclusion fluids. Cu is consistently below detection limits in brine inclusions from the IOCG and intrusion-related systems and Fe was not detected in the latter. Cl/Br and Na/Cl ratios of the IOCG inclusion fluids range from entirely evaporative brines (bittern fluids; e.g. Igarapé Bahia and Alvo 118) to values that indicate mixing with magma-derived brines. Cl/Br and Na/Cl ratios of the Breves inclusion fluids strongly suggest the involvement of magmatic brines, but that possibly also incorporated bittern fluids. Collectively, these data demonstrate that residual evaporative and magmatic brines were important components of the fluid regime involved in the formation of Cu-Au systems in the Carajás Mineral Province.

  15. Contact interaction of the Bi12GeO20, Bi12SiO20, and Bi4Ge3O12 melts with noble metals

    Science.gov (United States)

    Denisov, V. M.; Podkopaev, O. I.; Denisova, L. T.; Kuchumova, O. V.; Istomin, S. A.; Pastukhov, E. A.

    2014-02-01

    The sessile drop method is used to study the contact interaction of Ag, Au, Pd, Pt, and Ir with the Bi2O3-GeO2 and Bi2O3-SiO2 melts. These melts spread over Ag and Pd and, in some cases, over Au and Pt at a rather high speed and form equilibrium contact angles on Ir.

  16. Development and Manufacture of Bi-2223 Wires

    Science.gov (United States)

    Kobayashi, Shin-Ichi

    This chapter reviews Ag-sheathed (Bi, Pb)2Sr2Ca2Cu3Ox (Bi-2223) wire made by the powder-in-tube technique (PIT). The currently leading high-temperature superconductors (HTS) wire technology for practical use is Bi-2223 wire, made by the controlled over-pressure (CT-OP) sintering process. The CT-OP process uses pressures up to 30MPa during heat treatment. The technique densifies the Bi-2223 filaments and enhances the uniformity of the electrical and mechanical performance in the Bi-2223 wire. Today, Bi-2223 wires are used in most HTS applications, such as power cables, many kinds of magnets, and motors for ship propulsion and electric vehicles.

  17. Hyperfine interactions and electrical properties of multiferroic 0.5Bi{sub 0.95}Dy{sub 0.05}FeO{sub 3}-0.5Pb(Fe{sub 0.5}Nb{sub 0.5})O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Stoch, A; Kulawik, J [Institute of Electron Technology, Krakow Division, ul. Zablocie 39, 30-701 Krakow (Poland); Zachariasz, P; Stoch, P; Maurin, J, E-mail: stoch@ite.waw.p [Institute of Atomic Energy Polatom, 05-400 Otwock-Swierk (Poland)

    2010-03-01

    0.5Bi{sub 0.95}Dy{sub 0.05}FeO{sub 3}-0.5Pb(Fe{sub 0.5}Nb{sub 0.5})O{sub 3} is a multiferroic material, simultaneously revealing ferroelectric and antiferromagnetic ordering, synthesis is rather difficult. In this paper we present a conventional solid state reaction method for synthesis of 0.5Bi{sub 0.95}Dy{sub 0.05}FeO{sub 3}-0.5Pb(Fe{sub 0.5}Nb{sub 0.5})O{sub 3} perovskite. A series of methodological measurements were carried out to determine the basic structural and electromagnetical properties. X-ray diffraction studies have been made in order to determine a crystal structure. Moessbauer effect spectroscopy was used to identify the oxidation state of Fe. Electrical properties of the perovskite ceramic were examined with impedance spectroscopy. The impedance spectra were analysed by means of an equivalent electrical circuit, and results are discussed in the scope of the brick layer model without easy paths.

  18. Impedance and modulus spectroscopy characterization of Tb modified Bi{sub 0.8}A{sub 0.1}Pb{sub 0.1}Fe{sub 0.9}Ti{sub 0.1}O{sub 3} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Shweta; Rai, Radheshyam, E-mail: rshyam1273@gmail.com [School of Physics, Shoolini University, Himachal Pradesh (India); Bdikin, Igor [Centre for Mechanical Technology and Automation (TEMA), University of Aveiro (Portugal); Valente, Manuel Almeida [Departamento de Fisica, Universidade de Aveiro (Portugal)

    2016-01-15

    In this paper we present the impedance spectroscopy of ternary solid solutions of BiFeO{sub 3} , TbFeO{sub 3} and PbTiO{sub 3} , prepared by solid-state reaction method. The preliminary structural studies were carried out by X-ray diffraction technique, showing the formation of polycrystalline sample with ABO{sub 3} type of perovskite structure with hexagonal symmetry for Bi{sub 0.8}Tb{sub 0.1}Pb{sub 0.1}Fe{sub 0.9}Ti{sub 0.1}O{sub 3} system at room temperature. Dielectric and impedance study of this ceramic has been characterized in the temperature range 175 - 325 deg C and frequency range 100 Hz - 1 MHz. The maximum ferroelectric transition temperature (T{sub c} ) of this system was in the range 210 - 225 deg C with the dielectric constant having maximum value ∼ 2480 at 1 kHz. The complex impedance graph exhibited one impedance semicircle arc at all reported temperatures, which indicates that the impedance response is a Cole-Cole type relaxation. Single semicircle indicate that the grain effect of the bulk in ceramic. The bulk resistance of the material decreases with increasing temperature showing negative temperature showing a typical semiconducting property, i.e. negative temperature coefficient of resistance (NTCR) behavior. (author)

  19. Magnetic properties of Bi{sub 1.7}Pb{sub 0.4}Sr{sub 1.5}Ca{sub 2.5}Cu{sub 3.6}O{sub x}/(LiF){sub y} superconducting system

    Energy Technology Data Exchange (ETDEWEB)

    Mihalache, V.; Aldica, G.; Popa, S.; Crisan, A

    2003-02-15

    AC complex susceptibility (with and without a superimposed DC field) and DC magnetization measurements on (Bi,Pb)-2223 high-temperature superconductors with various amounts of LiF are presented. The results are discussed in the frame of the critical state model. The values of the intra- and inter-granular critical current density as well as of fields for full penetration are estimated. It can be seen that, in Bi{sub 1.7}Pb{sub 0.4}Sr{sub 1.5}Ca{sub 2.5}Cu{sub 3.6}O{sub x}/(LiF){sub y}, various amounts of LiF change the superconducting properties of both the grains and the inter-grain matrix. The intra-granular critical current density has similar values from both AC susceptibility and DC magnetization measurements, its highest value being attained for y=0.15. For all LiF-doped samples, a split of the peak corresponding to the dissipation in the grains was observed.

  20. Simulation of Pb(p,xn) and Bi(p,xn) Pro duction Cross Sections in the Incident Proton Energy Range up to 3 GeV%Ep 63 GeV质子入射铅、铋引起的中子产生双微分截面的模拟

    Institute of Scientific and Technical Information of China (English)

    张苏雅拉吐; 陈志强; 韩瑞; 刘星泉; 林炜平; 靳增雪; 刘建立; 石福东

    2014-01-01

    加速器驱动次临界系统(ADS)液态Pb-Bi散裂靶的设计中,需要可靠的理论计算工具精确地预言几个GeV能量范围的质子引起的散裂反应产生的各种粒子和核素。利用蒙特卡罗模拟软件包Geant4计算研究了800 MeV至3 GeV质子入射铅、铋材料引起的中子产生双微分截面。比较了Geant4不同物理模型得到的模拟结果与现有的实验数据。其中,Geant4的QGSP BERT和QGSP INCL ABLA物理模型模拟结果很好地再现了实验数据。本工作证实了Geant4蒙特卡罗模拟软件包适合用于能量高达3 GeV的质子入射铅、铋引起的中子产生双微分截面的模拟计算。%A detailed design of the liquid Pb-Bi spallation target of the Accelerator Driven Systems (ADS) requires powerful and reliable computational tools that can accurately predict particles and nuclides production by the proton induced spallation reactions in the energy range of a few GeV. In this paper, the neutron production double-differential cross sections for Pb and Bi target materials at incident proton kinetic energies between 800 MeV and 3 GeV are studied by calculations with Monte Carlo simulation package Geant4. The simulated results of Geant4 with several physics models are compared with available experimental data. The simulated results generated by QGSP BERT and QGSP INCL ABLA physics models of Geant4 well reproduce the available experimental data. The present results validated that Geant4 Monte Carlo simulation package is suitable for simulations of neutron production double-differential cross sections of proton induced reaction on Pb and Bi targets in the incident energy range up to 3 GeV.

  1. Systematics of hydrothermal alteration at the volcanic-hosted Falun Zn-Pb-Cu-(Au-Ag) deposit - implications for ore genesis, structure and exploration in a 1.9 Ga ore district, Fennoscandian Shield, Sweden

    Science.gov (United States)

    Kampmann, Tobias C.; Jansson, Nils J.; Stephens, Michael B.; Majka, Jarosław

    2016-04-01

    The Palaeoproterozoic, volcanic-hosted Falun Zn-Pb-Cu-(Au-Ag) sulphide deposit was mined for base and precious metals during several centuries, until its closure in 1992. The deposit is located in a 1.9 Ga ore district in the Bergslagen lithotectonic unit, Fennoscandian Shield, south-central Sweden. Both the ores and their host rock underwent polyphase ductile deformation, and metamorphism under amphibolite facies and later retrograde conditions at 1.9-1.8 Ga (Svecokarelian orogenic system). This study has the following aims: (i) Classify styles and intensities of alteration in the hydrothermally altered zone at Falun; (ii) identify precursor rocks to hydrothermally altered rocks and their spatial distribution at the deposit; (iii) evaluate the chemical changes resulting from hydrothermal alteration using mass change calculations; and (iv) assess the pre-metamorphic alteration assemblages accounting for the observed metamorphic mineral associations in the altered rocks at Falun. Results will have implications for both the ore-genetic and structural understanding of the deposit, as well as for local and regional exploration. Metamorphic mineral associations in the altered rocks include biotite-quartz-cordierite-(anthophyllite) and, more proximally, quartz-anthophyllite-(biotite-cordierite/almandine), biotite-cordierite-(anthophyllite) and biotite-almandine-(anthophyllite). The proximal hydrothermally altered zone corresponds to intense chlorite-style alteration. Subordinate dolomite or calcite marble, as well as calc-silicate (tremolite, diopside) rocks are also present at the deposit. Metavolcanic rocks around the deposit are unaltered, weakly sericitized or sodic-altered. Immobile-element (e.g. Zr, TiO2, Al2O3, REE) systematics of the silicate-rich samples at and around the deposit suggest that the precursors to the hydrothermally altered rocks at Falun were predominantly rhyolitic in composition, dacitic rocks being subordinate and mafic-intermediate rocks

  2. Spectral and thermodynamic properties of Ag(I), Au(III), Cd(II), Co(II), Fe(III), Hg(II), Mn(II), Ni(II), Pb(II), U(IV), and Zn(II) binding by methanobactin from Methylosinus trichosporium OB3b.

    Science.gov (United States)

    Choi, Dong W; Do, Young S; Zea, Corbin J; McEllistrem, Marcus T; Lee, Sung-W; Semrau, Jeremy D; Pohl, Nicola L; Kisting, Clint J; Scardino, Lori L; Hartsel, Scott C; Boyd, Eric S; Geesey, Gill G; Riedel, Theran P; Shafe, Peter H; Kranski, Kim A; Tritsch, John R; Antholine, William E; DiSpirito, Alan A

    2006-12-01

    Methanobactin (mb) is a novel chromopeptide that appears to function as the extracellular component of a copper acquisition system in methanotrophic bacteria. To examine this potential physiological role, and to distinguish it from iron binding siderophores, the spectral (UV-visible absorption, circular dichroism, fluorescence, and X-ray photoelectron) and thermodynamic properties of metal binding by mb were examined. In the absence of Cu(II) or Cu(I), mb will bind Ag(I), Au(III), Co(II), Cd(II), Fe(III), Hg(II), Mn(II), Ni(II), Pb(II), U(VI), or Zn(II), but not Ba(II), Ca(II), La(II), Mg(II), and Sr(II). The results suggest metals such as Ag(I), Au(III), Hg(II), Pb(II) and possibly U(VI) are bound by a mechanism similar to Cu, whereas the coordination of Co(II), Cd(II), Fe(III), Mn(II), Ni(II) and Zn(II) by mb differs from Cu(II). Consistent with its role as a copper-binding compound or chalkophore, the binding constants of all the metals examined were less than those observed with Cu(II) and copper displaced other metals except Ag(I) and Au(III) bound to mb. However, the binding of different metals by mb suggests that methanotrophic activity also may play a role in either the solubilization or immobilization of many metals in situ.

  3. 从含高铜铅氰化金泥中提取金、银、铜、铅全湿法工艺%Total-wet method to extract Au, Ag, Cu and Pb from cyanidation gold-slime containing high copper and lead

    Institute of Scientific and Technical Information of China (English)

    胡宪

    2011-01-01

    A total-wet method to extract Au, Ag, Cu and Pb from cyanidation gold-slime containing high copper and lead is put forward by experiments.The gold slim is pretreated by adding a sort of decoppering agent in the sulfuric acid medium, and the decoppering rate is 98 %.The gold extraction rate from the extracting slag after pretreatment is 99.5 %.Sponge gold is reduced with mixed reducer,and after impurity removement, the gold purity meets the Au-2 standard.%根据试验结果,提出了一种从含高铜铅氰化金泥中提取Au、Ag、Cu、Pb全湿法工艺.该工艺在硫酸介质中加入一种除铜剂对氰化金泥进行预处理,除铜率达98%;预处理后的含金渣浸金,金浸出率达99.5%以上;用混合还原荆还原出的海绵金,经去杂处理,金的成色达到Au-2标准.

  4. Luminescence efficiency growth in wide band gap semiconducting Bi2O3 doped Cd0.4Pb0.1B0.5 glasses and effect of γ-irradiation

    Science.gov (United States)

    Marzouk, M. A.; Ibrahim, S.; Hamdy, Y. M.

    2014-11-01

    Cadmium lead borate glasses together with other glasses containing different Bi2O3-doping concentrations (2.5, 5, 7.5, 10 mol%) were prepared by conventional melt annealing method. The density and molar volume values were calculated to obtain some insight on the packing density and arrangement in the network. Also their optical and structural properties have been characterized by means of X-ray diffraction, UV-visible spectroscopy, luminescence spectroscopy and FTIR spectroscopy. Optical measurements have been used to determine the optical band gap (Eg), Urbach energy (ΔE) and the refractive index (n). The results demonstrate the effective rule of Bi2O3 on the studied glasses. The undoped and Bi2O3 doped - glass show strong extended UV-near visible absorption bands which are attributed to the collective presence of both trace iron impurities from raw materials and also the sharing of bismuth Bi+3 ions. Furthermore, the luminescence intensity strongly increases with increasing Bi2O3 content which may be attributed to transfer of energy from transitions in its energy levels. It has been revealed that the decreasing values of optical band gap and band tail can be understood and related in terms of the structural changes that are taking place in the glass samples. The infrared absorption spectra of the prepared glasses show characteristic absorption bands related to the borate network (BO3, BO4 groups) together with vibrational modes due to Bi-O groups upon the introduction of Bi2O3. The prepared samples reveal a very limited response towards of gamma irradiation which reflects its shielding behavior towards the effect of such type of irradiation.

  5. Transmission electron microscopy investigation of Bi-2223/Ag tapes

    DEFF Research Database (Denmark)

    Andersen, L.G.; Bals, S.; Tendeloo, G. Van

    2001-01-01

    The microstructure of (Bi,Pb)(2)Sr2Ca2CuOx (Bi-2223) tapes has been investigated by means of transmission electron microscopy (TEM) and high-resolution TEM. The emphasis has been placed on: (1) an examination of the grain morphology and size, (2) grain and colony boundary angles, which are formed...

  6. NEUTRON DECAY OF THE ISOBARIC ANALOG STATE IN BI-209

    NARCIS (Netherlands)

    BORDEWIJK, JA; BALANDA, A; BEAUMEL, D; BLOMGREN, J; BRANDENBURG, S; VANTHOF, G; HARAKEH, MN; HOFSTEE, MA; JANECKE, J; KRASZNAHORKAY, A; LAURENT, H; NILSSON, L; OLSSON, N; PERRINO, R; SIEBELINK, R; SODERMAN, PO; VANDERWERF, SY; VANDERWOUDE, A

    1994-01-01

    The isospin-forbidden neutron decay of the isobaric analog state in Bi-208 has been measured, following its excitation via the Pb-208(He-3, t)Bi-208 reaction at 61.2 MeV. In contrast to the proton decay, which is direct, the neutron decay spectrum has a statistical shape. Its branching ratio is dete

  7. One disorder out of two orders: Synthesis and crystal structures of cation-ordered PbNaF2NO3, anion-ordered Pb2OFNO3, and continuous disordered (Pb, Na)2(O,F)2-δNO3 solid solution with Sillén-derived structures

    Science.gov (United States)

    Charkin, Dmitri O.; Plokhikh, Igor V.; Zaloga, Aleksandr N.; Lobanov, Maxim V.; Kazakov, Sergey M.

    2017-09-01

    Two new Sillén-like layered lead fluoride nitrates, PbNaF2NO3 and Pb2OFNO3, have been prepared at 300 °C. PbNaF2NO3 is a structural analog of alkaline earth - bismuth oxyhalides, BaBiO2X and SrBiO2X (X = Cl - I), but not the corresponding nitrates, SrBiO2NO3 or BaBiO2NO3. Pb2OFNO3 is analogous to the corresponding halides, Pb2OFX (X = Cl, Br, I). Both structures belong to orthorhombic symmetry and demonstrate Na/Pb and O/F ordering, respectively. A continuous solid solution is formed between PbNaF2NO3 and Pb2OFNO3 which demonstrates neither cation nor anion ordering; the structure of intermediate composition Pb1.5Na0.5F1.5O0.5NO3 was refined in tetragonal symmetry and is indeed very close to that of PbBiO2NO3 and CaBiO2NO3. In PbNaF2NO3, the O:F ratio may be varied to a slight extent, PbNaF2-2yOyyNO3, which also breaks the Na - Pb cation ordering. Analogous fluoride halides could not be prepared. Structural analogies to lead, bismuth, and antimony oxyhalides are discussed.

  8. Po-210 and Pb-210 as atmospheric tracers and global atmospheric Pb-210 fallout: a review.

    Science.gov (United States)

    Baskaran, M

    2011-05-01

    Over the past ∼ 5 decades, the distribution of (222)Rn and its progenies (mainly (210)Pb, (210)Bi and (210)Po) have provided a wealth of information as tracers to quantify several atmospheric processes that include: i) source tracking and transport time scales of air masses; ii) the stability and vertical movement of air masses iii) removal rate constants and residence times of aerosols; iv) chemical behavior of analog species; and v) washout ratios and deposition velocities of aerosols. Most of these applications require that the sources and sink terms of these nuclides are well characterized. Utility of (210)Pb, (210)Bi and (210)Po as atmospheric tracers requires that data on the (222)Rn emanation rates is well documented. Due to low concentrations of (226)Ra in surface waters, the (222)Rn emanation rates from the continent is about two orders of magnitude higher than that of the ocean. This has led to distinctly higher (210)Pb concentrations in continental air masses compared to oceanic air masses. The highly varying concentrations of (210)Pb in air as well the depositional fluxes have yielded insight on the sources and transit times of aerosols. In an ideal enclosed air mass (closed system with respect to these nuclides), the residence times of aerosols obtained from the activity ratios of (210)Pb/(222)Rn, (210)Bi/(210)Pb, and (210)Po/(210)Pb are expected to agree with each other, but a large number of studies have indicated discordance between the residence times obtained from these three pairs. Recent results from the distribution of these nuclides in size-fractionated aerosols appear to yield consistent residence time in smaller-size aerosols, possibly suggesting that larger size aerosols are derived from resuspended dust. The residence times calculated from the (210)Pb/(222)Rn, (210)Bi/(210)Pb, and (210)Po/(210)Pb activity ratios published from 1970's are compared to those data obtained in size-fractionated aerosols in this decade and possible reasons for

  9. Development of materials design tool and its application in Pb-free micro-solders in electronic package

    Institute of Scientific and Technical Information of China (English)

    OHNUMA; Ikuo; KAINUMA; Ryosuke; ISHIDA; Kiyohito; CHANG; Austin; Y.

    2010-01-01

    A materials design tool for developing Pb-free soldering alloys in electronic package was developed based on comprehensive experimental data of phase equilibria and thermodynamic properties data accumulated with the CALPHAD (calculation of phase diagrams) method and contains 10 elements,namely,Ag,Au,Bi,Cu,In,Ni,Sb,Sn,Zn and Pb.It can handle the calculation of phase diagrams in all combinations of these elements and all composition ranges.In addition,based on this tool,the liquidus,solidus,phase fractions and constitutions,equilibrium and non-equilibrium solidification behavior,surface tension and viscosity of liquid,diffusion reactions and microstructural evolution,etc.can be predicted.Typical examples of the calculation and application of this tool are presented.The design tool is expected to be a powerful tool for the development of Pb-free solders,as well as for promoting the understanding of the interfacial phenomena between Cu substrate and Pb-free solders in electronic packaging technology.

  10. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon

    2002-05-31

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  11. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon [Univ. of California, Berkeley, CA (United States)

    2002-05-01

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  12. Multiple production of mesons in Au+Au and Pb+Pb collisions

    CERN Document Server

    Guptaroy, P; Bhattacharya, D P; Bhattacharya, S

    2003-01-01

    The study presented here pertains to the model-based analyses for production of some important charged secondaries in lead-lead and gold-gold collisions at AGS, SPS and RHIC energies. We examine the role of a particular version of the Sequential Chain Model (SCM) in interpreting the data on the production of only the secondary mesons of the most abundant variety in relativistic nucleus-nucleus collisions. The initial results derived for basic pp collisions have been transformed into the corresponding cases for nucleus-nucleus collisions through the appropriate physical-mathematical formalisms. The agreement between the model of choice and the measured data for the most important varieties of mesons in the two above-stated nuclear collisions could so far be rated to be barely modest. This is presumably due to our neglect of the effects of rescattering and cascading, while we choose to obtain only the first-order results in the initial attempt. (47 refs).

  13. Lead Telluride Doped with Au as a Very Promising Material for Thermoelectric Applications

    Directory of Open Access Journals (Sweden)

    Pantelija M. Nikolic

    2015-01-01

    Full Text Available PbTe single crystals doped with monovalent Au or Cu were grown using the Bridgman method. Far infrared reflectivity spectra were measured at room temperature for all samples and plasma minima were registered. These experimental spectra were numerically analyzed and optical parameters were calculated. All the samples of PbTe doped with Au or Cu were of the “n” type. The properties of these compositions were analyzed and compared with PbTe containing other dopants. The samples of PbTe doped with only 3.3 at% Au were the best among the PbTe + Au samples having the lowest plasma frequency and the highest mobility of free carriers-electrons, while PbTe doped with Cu was the opposite. Samples with the lowest Cu concentration of 0.23 at% Cu had the best properties. Thermal diffusivity and electronic transport properties of the same PbTe doped samples were also investigated using a photoacoustic (PA method with the transmission detection configuration. The results obtained with the far infrared and photoacoustic characterization of PbTe doped samples were compared and discussed. Both methods confirmed that when PbTe was doped with 3.3 at% Au, thermoelectric and electrical properties of this doped semiconductor were both significantly improved, so Au as a dopant in PbTe could be used as a new high quality thermoelectric material.

  14. Auger analysis of the PbS-Si heterojunction

    Science.gov (United States)

    Elabd, H.; Steckl, A. J.

    1980-05-01

    The chemical structure of the solution-grown PbS-Si hetero-junction was studied by Auger Electron Spectroscopy. Auger depth profiles indicate a PbS film of uniform composition. No major contaminants were observed in the bulk of the PbS film. At the PbS-Si interface the only impurity observed was an oxygen peak, corresponding to approximately 1% atomic concentration. Heating the growth solution enhances the chemical reaction and deposition rates without altering the profiles of the elements at the interface. Similar oxygen peaks were detected at the Au-PbS interface and at the interface between consecutive PbS films. The interface oxygen concentration in the PbS-Si (100) structure is roughly twice that present in the PbS-Si (111) structure. Heat treatment in air increased the interface and surface oxygen concentration by a factor of 2 to 5. The same treatment in N2} ambient had only a slight effect on the surface oxygen concentration but enhanced the interface oxygen concentration. The oxygen at the Au-PbS interface showed similar sensitivity to heat treatment. Oxygen content at the interface of HJs formed on unpolished Si was double that in HJs formed on polished Si. The relative intensity of the S to Pb peaks in the bulk of the PbS film compares closely with that measured on the cleaved surface of natural single crystal galena. The Pb: S peak ratio was roughly constant throughout the PbS film and at the PbS-Si interface. Fe and Cl contaminants were observed at the surface of the PbS film, along with significant changes in the Pb:S ratio. The simultaneous detection of Pb, S and Si near the interface is attributed to the presence of surface irregularity caused by a secondary PbS macrostructure consisting of isolated chain-like clusters.

  15. Presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of multiferroic (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} solid solution: A Rietveld study

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Rishikesh, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2014-07-28

    We present here the results of structural studies on multiferroic (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} solid solution using Rietveld analysis on powder x-ray diffraction data in the composition range 0.35 ≤ x ≤ 0.55. The stability region of various crystallographic phases at room temperature for (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} is determined precisely. Structural transformation from pseudo-cubic (x ≤ 0.40) to tetragonal (x ≥ 0.50) phase is observed via phase coexistence region demarcating the morphotropic phase boundary. The morphotropic phase boundary region consists of coexisting tetragonal and monoclinic structures with space group P4mm and Pm, respectively, stable in composition range 0.41 ≤ x ≤ 0.49 as confirmed by Rietveld analysis. The results of Rietveld analysis completely rule out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier workers. A comparison between the bond lengths for “B-site cations-oxygen anions” obtained after Rietveld refinement, with the bond length calculated using Shannon-Prewitt ionic radii, reveals the ionic nature of B-O (Ni/Ti-O) bonds for the cubic phase and partial covalent character for the other crystallographic phases.

  16. Bennani-Chraïbi Mounia, Catusse Myriam, Santucci Jean-Claude, Scènes et coulisses de l’élection au Maroc. Les législatives 2002, IREMAM-Karthala, Paris-Aix, 2004, 318 p.

    Directory of Open Access Journals (Sweden)

    Pierre Vermeren

    2007-07-01

    Full Text Available À l’heure où se profilent les élections législatives marocaines de 2007, susceptibles de réaménager profondément la vie politique du Royaume, il n’est pas inutile de faire retour sur les législatives du 27 septembre 2002. Ces premières élections générales du règne de Mohammed VI ont joué un rôle déterminant dans la visibilité de l’islamisme marocain, tant au plan intérieur qu’au plan international. Avec l’élection de 42 députés du PJD (Parti de la justice et de développement,  elles ont fait...

  17. Re-Os isotopic and trace element compositions of pyrite and origin of the Cretaceous Jinchang porphyry Cu-Au deposit, Heilongjiang Province, NE China

    Science.gov (United States)

    Zhang, Peng; Huang, Xiao-Wen; Cui, Bin; Wang, Bo-Chao; Yin, Yi-Fan; Wang, Jing-Rui

    2016-11-01

    The Jinchang Cu-Au deposit in Northeast China contains more than 76 tons of Au and 4683 tons of Cu with average ore grades of 11.34 g/t Au and 1.44% Cu. The deposit is typical of porphyry types and consists of gold orebodies mainly hosted in a ∼113 Ma granitic porphyry and breccia pipes within the porphyry intrusion. Mineralization is closely associated with early potassic alteration and late phyllic alteration. Pyrite is the main Au-bearing mineral and contains 1.48-18.9 ppb Re and 11.4-38 ppt common Os. Extremely low common Os concentrations and high Re/Os ratios are indicative of derivation of ore-forming materials from the crust. Low Re in pyrite from the Jinchang deposit may indicate a mixing source of mantle and crust or a crustal source. Five Re-Os isotopic analyses yield a model 1 isochron age of 114 ± 22 Ma (2σ, MSWD = 0.15), similar to the age of the host porphyry. Pyrite contains detectable Co, Ni, Cu, Zn, As, Ag, Au, Sb, Pb and Bi. Pyrite has Co/Ni ratios similar to that of volcanogenic and hydrothermal sulfide deposits, indicating a magmatic-hydrothermal origin, and has Au and As contents similar to that of porphyry-epithermal systems. Pyrite grains from potassic and phyllic alteration stages have different trace element contents, reflecting the evolution of ore-forming fluids from magmatic dominated to magmatic mixed with meteoric water. In combination with regional geology, our new results are suggestive of origin of the Jinchang Cu-Au deposit from contemporary intrusions of granitic porphyries related to the Early Cretaceous subduction of the Paleo-Pacific plate.

  18. Transport and ac susceptibility measurements on silver wrapped pellets of Bi1.7Pb0.35Sr1.9Ca2.1Cu3Oy superconductors

    Science.gov (United States)

    Terzioglu, C.; Yegen, D.; Varilci, A.; Belenli, I.

    2009-03-01

    The effect of the cooling rates on oxygen content of silver sheathed Bi-2223 bulk superconducting samples was investigated performing dc electrical resistivity, transport critical current density, ac susceptibility and x-ray diffraction (XRD) measurements. The bulk samples with Ag sheathing were annealed under identical conditions and cooled with rates of 25° C / h, 50° C / h, 75° C / h, and 100° C / h. We estimated the transition temperatures from both dc resistivity and ac susceptibility as a function of temperature measurements. It is observed that Tc and Jc depend on cooling rates of the samples. Tc and Jc decrease with increasing cooling rates. The imaginary part of ac susceptibility measurements is used to calculate inter-granular critical current density using the Bean Model. Jc(Tp) is also seen to decreases with increasing cooling rates. The peak temperature, Tp, in the imaginary part of the ac susceptibility is shifted to a lower temperature with increasing cooling rates as well as increasing ac magnetic fields. The force pinning density decreased with increasing the cooling rates. XRD patterns are given to determine lattice parameter c and obtain information about Bi-2223 and Bi-2212 phases.

  19. Geological setting, isotope studies (C, O and Pb) and associated metals in the Tocantinzinho gold deposit, Tapajos domain, Tapajos-Parima Province; Contexto geologico, estudos isotopicos (C, O e Pb) e associacao metalica do deposito aurifero Tocantinzinho, dominio Tapajos, Provincia Tapajos-Parima

    Energy Technology Data Exchange (ETDEWEB)

    Villas, Raimundo Netuno Nobre [Universidade Federal do Para (UFPA), Belem, PA (Brazil); Santiago, Erika Suellen Barbosa; Castilho, Marilia Portela, E-mail: netuno@ufpa.br, E-mail: esbsantiago@gmail.com, E-mail: castilho.marilia@hotmail.com [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Geociencias. Programa de Pos-graduacao em Geologia e Geoquimica

    2013-03-15

    The Tocantinzinho ore deposit is located along a NW-SE-trending lineament, southwestern of Itaituba (Para, Brazil), and is the largest known gold deposit of the Tapajos Province. The host Tocantinzinho granite is essentially isotropic and dominated by syenogranites and monzogranites that have been weakly to moderately altered by hydrothermal fluids. Microclinization (earliest), chloritization, sericitization, silicification and carbonatization (latest) are the main types of alteration. Most mineralization was contemporaneous with the sericitization/silicification and is represented by sulfide- and gold-bearing veinlets which locally occur as stockwork. Pyrite, chalcopyrite, sphalerite and galena are the most common sulfides. Among the ore metals, Cu, Pb and Zn present the highest contents, but Mo, As and Bi locally show anomalous concentrations. The relationship of Au with Cu, Pb or Zn is at random and the Au/Ag ratios range from 0.05 to 0.5. The higher the sulfide contents, the higher the Au concentrations, though it occurs mainly included in pyrite. Zircon monocrystals from the Tocantinzinho granite yielded an average Pb-Pb age of 1982 {+-}8Ma and may represent an earlier event of the Creporizao magmatic arc. {delta}{sup 13}C{sub PDB} values for calcite from the carbonatization stage fall dominantly between -3.45 and -2.29 Per-Mille-Sign , being compatible with a deep crustal source that may include carbonatite reservoirs. In turn, {delta}{sup 18}O{sub SMOW} values vary from +5.97 to +14.10 Per-Mille-Sign , being indicative of magmatic derivation, although the less positive values suggest contribution from surficial waters. Unpublished fluid inclusion study reveals the presence of aquo-carbonic fluids, whose CO{sub 2} could have been dissolved in the granitic magma rather than being related to the shear zone. The available data allow the Tocantinzinho deposit to be classified as a granite-hosted, intrusion-related gold deposit. (author)

  20. Microfabricated interdigitated Au electrode for voltammetric determination of lead and cadmium in Chinese mitten crab (Eriocheir sinensis).

    Science.gov (United States)

    Xu, Yiwei; Zhang, Wen; Shi, Jiyong; Zou, Xiaobo; Li, Zhihua; Zhu, Yaodi

    2016-06-15

    An in-situ plating bismuth modified interdigitated Au electrode (IAE) was developed for determination of Pb(2+) and Cd(2+) in crab. The IAE was fabricated and used as counter electrode and working electrode. Cyclic voltammetry (CV) was performed with the IAE for studying electrochemical performance, showing clear redox peaks. The key operational parameters were optimized, which were 600 μg L(-1) of Bi(3+) concentration, 0.1 mol L(-1) of acetate buffer (pH 4.5), -1.2V of deposition potential and 180 s of deposition time. Under optimized condition, the linear range of IAE was from 5 to 50 μg L(-1) for both metal ions, with detection limit (threefold signal-to-noise) of 0.74 μg L(-1) for Pb(2+) and 0.86 μg L(-1) for Cd(2+). Finally, the developed sensor was applied to detect Pb(2+) and Cd(2+) in crab extract solutions by standard addition method. The results were in good agreement with outcomes obtained by inductively coupled plasma mass spectrometry.

  1. CHEMICAL DETERMINATION OF HEAVY METALS IN PB AND ZN CONCENTRATES OF TREPÇA (KOSOVO AND CORRELATIONS COEFFI CIENTS STUDY BETWEEN CHEMICAL DATA

    Directory of Open Access Journals (Sweden)

    Fatbardh Gashi

    2017-03-01

    Full Text Available Kosovo ore deposits are located in the Trepça belt which extends for over 80 km. The concentrate produced by the flotation process of the Trepça metallurgical corporation contains a considerable quantity of valuable metals, such as Pb, Zn, Fe and minor accompanying metals such as Cd, Cu, As, Sb, Bi, Ag, Au, etc. The subject of this work was to assess the concentration of major and minor metals in lead and zinc concentrates of Trepça and to study the correlation coefficients between metals. Chemical determination of concentrates was performed by using atomic absorption spectroscopy (AAS. In the content on lead concentrate samples, the following were found: Pb>Fe>Zn> Ag> As>Sb>Cd. In the content of zinc concentrate, the following were found: Zn>Fe>Pb>Ag>As>Cd. The program “Statistica ver. 6.0” has been used for calculations of basic statistical parameters, relationships between data and cluster analysis of R-mode. R-mode cluster analysis on lead concentrate samples showed that Pb has the closest linkages with Fe and they form one branch of the dendogram. On the zinc concentrate samples, Zn has the closest linkages with Fe and they form one branch of the dendogram.

  2. Agile BI – The Future of BI

    Directory of Open Access Journals (Sweden)

    Mihaela MUNTEAN

    2013-01-01

    Full Text Available In a rapidly changing economy, Business Intelligence solutions have to become more agile. This paper attempts to discuss some questions which help in creating an agile BI solution such as: What is Agile? Why agile is so well suited for BI? Which are the key elements that promote an agile BI solution? Also, this paper briefly looks at technologies that can be used for enabling an agile BI solution.

  3. LA-ICP-MS Zircon U-Pb Dating of the Dacite Porphyry from Zijinshan Cu-Au Deposit and its Metallogenetic Implications%福建紫金山矿田晚中生代英安玢岩形成时代及其成矿意义

    Institute of Scientific and Technical Information of China (English)

    胡春杰; 黄文婷; 包志伟; 梁华英; 王春龙

    2012-01-01

    The dacite porphyry occurs in the volcanic caldera of Zijinshan ore field and closely associates with the Cu-Au mineralization.The LA-ICP-MS zircon U-Pb dating of two dacite porphyry samples yields weighted mean ages of ( 105.0 ±0.7) Ma and ( 105.0 ±2.2) Ma,respectively.These results suggest that the dacite porphyry was formed proximately contemporarily with the other two Mo and Cu mineralized granite porphyries,i.e.,the Sifang and Luoboling granite porphyries.The dacite and granite intrusives are characterized by high Ce4+/Ce3+ ratios,which indicates that the magmatic system was of oxidative and therefore consistent with the huge Cu-Mo-Au ore-forming potential of the dacite and granite porphyries.Moreover,the similarities of age,geochemical characteristics and mineralization demonstrate that the Cu-Mo-Au mineralization in the Zijinshan ore field is most likely a unified porphyry ore-forming system.%福建紫金山Cu-Mo-Au-Ag多金属矿田是一个完整的斑岩-浅成低温热液矿床成矿体系.英安玢岩主要分布在紫金山Au-Cu矿床内火山机构及其附近,与高品位Au-Cu矿体空间上联系密切,是矿田内火山-侵入岩浆过程的一个重要环节.采自矿区的两个英安玢岩样品LA-ICP-MS锫石U-Pb定年结果分别为(105.0±0.7) Ma(MSWD =0.83)和(105.0±2.2) Ma (MSWD=1.70),其形成时代与区内Mo-Cu矿化的萝卜岭和四方岩体形成时代相近.三个岩体形成时代及地球化学特征的相似性表明它们应为同源岩浆演化的产物,它们均具有较高的锆石Ce4+/Ce3+值,即岩浆体系具有较高的氧逸度,与区内斑岩成矿体系巨量金属堆积的地质事实相一致.英安玢岩的精确定年表明,紫金山Cu-Au矿与萝卜岭Mo-Cu矿及四方岩体有关的Mo矿床为同一斑岩成矿体系的产物.

  4. Classification of Broken Hill-Type Pb-Zn-Ag Deposits: A Refinement

    Science.gov (United States)

    Spry, P. G.; Teale, G. S.; Steadman, J. A.

    2009-05-01

    Broken Hill Hill-type Pb-Zn-Ag (BHT) deposits constitute some of the largest ore deposits in the world. The Broken Hill deposit is the largest accumulation of Pb, Zn, and Ag on Earth and the Cannington deposit is currently the largest silver deposit. Characteristic features of BHT deposits include: 1. high Pb+Zn+Ag values with Pb > Zn; 2. Metamorphism to amphibolite-granulite facies; 3. Paleo-to Mesoprotoerozoic clastic metasedimentary host rocks; 4. Sulfides that are spatially associated with bimodal (felsic and mafic) volcanic rocks, and stratabound gahnite- and garnet-bearing rocks and iron formations, 5. Stacked orebodies with characteristic Pb:Zn:Ag ratios and skarn-like Fe-Mn-Ca-F gangue assemblages, and the presence of Cu, Au, Bi, As, and Sb; and 6. Sulfur-poor assemblages. Broken Hill (Australia) has a prominent footwall feeder zone whereas other BHT deposits have less obvious alteration zones (footwall garnet spotting and stratabound alteration haloes). Deposits previously regarded in the literature as BHT deposits are Broken Hill, Cannington, Oonagalabie, Menninie Dam, and Pegmont (Australia), Broken Hill, Swartberg, Big Syncline, and Gamsberg (South Africa), Zinkgruvan (Sweden), Sullivan, Cottonbelt, and Foster River (Canada), and Boquira (Brazil). Of these deposits, only the Broken Hill (Australia, South Africa), Pinnacles, Cannington, Pegmont, and Swartberg deposits are BHT deposits. Another BHT deposit includes the Green Parrot deposit, Jervois Ranges (Northern Territory). The Foster River, Gamsberg, and Sullivan deposits are considered to be "SEDEX deposits with BHT affinities", and the Oonagalabie, Green Mountain (Colorado), and Zinkgruvan are "VMS deposits with BHT affinities". In the Broken Hill area (Australia), Corruga-type Pb-Zn-Ag deposits occur in calc-silicate rocks and possess some BHT characteristics; the Big Syncline, Cottonbelt, Menninie Dam, and Saxberget deposits are Corruga-type deposits. SEDEX deposits with BHT affinities, VMS

  5. Modification of carbon screen-printed electrodes by adsorption of chemically synthesized Bi nanoparticles for the voltammetric stripping detection of Zn(II), Cd(II) and Pb(II).

    Science.gov (United States)

    Rico, Ma Angeles Granado; Olivares-Marín, Mara; Gil, Eduardo Pinilla

    2009-12-15

    A simple procedure for the chemical synthesis of bismuth nanoparticles and subsequent adsorption on commercial screen-printed carbon electrodes offer reliable quantitation of trace zinc, cadmium and lead by anodic stripping square-wave voltammetry in nondeareated water samples. The influence of two hydrodynamic configurations (convective cell and flow cell) and the effect of various experimental variables upon the stripping signals at the bismuth-coated sensor are explored. The square-wave peak current signal is linear over the low ng mL(-1) range (120 s deposition), with detections limits ranging from 0.9 to 4.9 ng mL(-1) and good precision. Applicability to waste water certified reference material and drinking water samples is demonstrated. The attractive behaviour of the new disposable Bi nanoparticles modified carbon strip electrodes, coupled with the negligible toxicity of bismuth, hold great promise for decentralized heavy metal testing in environmental and industrial effluents waters.

  6. The role of spontaneous polarization in the negative thermal expansion of tetragonal PbTiO3-based compounds.

    Science.gov (United States)

    Chen, Jun; Nittala, Krishna; Forrester, Jennifer S; Jones, Jacob L; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

    2011-07-27

    PbTiO(3)-based compounds are well-known ferroelectrics that exhibit a negative thermal expansion more or less in the tetragonal phase. The mechanism of negative thermal expansion has been studied by high-temperature neutron powder diffraction performed on two representative compounds, 0.7PbTiO(3)-0.3BiFeO(3) and 0.7PbTiO(3)-0.3Bi(Zn(1/2)Ti(1/2))O(3), whose negative thermal expansion is contrarily enhanced and weakened, respectively. With increasing temperature up to the Curie temperature, the spontaneous polarization displacement of Pb/Bi (δz(Pb/Bi)) is weakened in 0.7PbTiO(3)-0.3BiFeO(3) but well-maintained in 0.7PbTiO(3)-0.3Bi(Zn(1/2)Ti(1/2))O(3). There is an apparent correlation between tetragonality (c/a) and spontaneous polarization. Direct experimental evidence indicates that the spontaneous polarization originating from Pb/Bi-O hybridization is strongly associated with the negative thermal expansion. This mechanism can be used as a guide for the future design of negative thermal expansion of phase-transforming oxides.

  7. Contribution to the study of electromagnetic calorimeter with PbWO{sub 4} crystals in the CMS experiment at LHC; Contribution a l`etude du calorimetre electromagnetique a cristaux de PbWO{sub 4} de l`experience CMS au LHC

    Energy Technology Data Exchange (ETDEWEB)

    Benhammou, Y. [Lyon-1 Univ., 69 (France)

    1997-01-13

    The Higgs bosons can be observed in the [90-130] GeV mass range in the channel h -> {gamma}{gamma} if a high resolution electromagnetic calorimeter is used. The needed performances are met in the Pb W O{sub 4} crystals. This thesis is devoted to the study of the first Pb W O{sub 4} crystals (23 cm length) and their associated electronic equipment. Of crucial importance it was found to be the behaviour of these crystals under long radiation exposure. The understanding of the radiation effects, the crystal growth procedure mastering and the realization of a green light monitoring system of high performance were successful results obtained in the study described in this thesis. A rather high energy (0.6 % at 100 GeV) and position resolution was achieved by using a APD readout. In addition, the prototype of a final readout chain of large dynamic range and low consumption was built with very encouraging results. Concerning the APDs it was established that increasing the active surface and reduction of exceeding noise factor F improves significantly the stochastic term in the energy resolution. Besides, a complete readout chain comprising current preamplifiers, a linear compressing (multi-slope) system and a fast ADC (40 MHz), were found necessary to met the requirements imposed on the high performing Pb W O{sub 4} calorimeter. Research and development works based on the pioneering studies described in this thesis devoted to the crystal calorimeters are underway 77 refs.

  8. Preparation of flowerlike BiOBr/Bi2MoO6 composite superstructures and the adsorption behavior to dyes

    Science.gov (United States)

    He, Qiong; Ni, Yonghong; Ye, Shiyong

    2017-05-01

    Flowerlike BiOBr/Bi2MoO6 composite superstructures were synthesized by a simple solvothermal route with subsequent direct precipitation at room temperature, employing bismuth nitrate, sodium molybdate, and cetyltrimethylammonium bromide (CTAB) as the raw materials. The phase and the morphology of the as-prepared products were characterized by SEM, TEM, SAED, XRD and EDS. BET investigation proved the mesoporous structure of flowerlike BiOBr/Bi2MoO6 composite superstructures. It was found that the composite superstructures exhibited higher adsorption ability to methylene blue (MB) and pyronine B (PB) dyes from their solutions than single component (BiOBr or Bi2MoO6). As a case, the adsorption behavior of MB aqueous solution on BiOBr/Bi2MoO6 composite superstructures was detailedly studied, including the adsorption isotherm, kinetics and thermodynamic parameters. The results indicated that flowerlike BiOBr/Bi2MoO6 composite superstructures have potential applications in the field of wastewater treatment.

  9. Structural and Moessbauer effect studies of 0.1Bi{sub 0.95}Dy{sub 0.05}FeO{sub 3}-0.9Pb(Fe{sub 2/3}W{sub 1/3})O{sub 3} multiferroic

    Energy Technology Data Exchange (ETDEWEB)

    Stoch, P; Maurin, J; Zachariasz, P [Institute of Atomic Energy - POLATOM, 05-400 Otwock - Swierk (Poland); Stoch, A; Kulawik, J, E-mail: stoch@ite.waw.pl [Institute of Electron Technology Krakow Division, Zablocie 39, 30 -701 Krakow (Poland)

    2011-10-29

    Multiferroics which are simultaneously ferroelectric and magnetically ordered are of great importance both for fundamental solid state physics and for modern technology. The polycrystalline sample of 0.1Bi{sub 0.95}Dy{sub 0.05}FeO{sub 3} - 0.9Pb(Fe{sub 2/3}W{sub 1/3})O{sub 3} were synthesized using standard sintering procedure. Crystal phase purity and crystal structure were determined using XRD method. The obtained crystal structure of the compound is a tetragonally distorted perovskite like structure (P4mm) with lattice parameters a = b = 3.987 A, c = 3.990 A. Moessbauer Effect (ME) studies were performed on {sup 57}Fe nuclei at 77K. The obtained spectra are composed of three Zeeman sextets. In the middle part of the obtained spectra there is observed paramagnetic dublet, which could be designated to impurity phase, which wasn't reveled on XRD pattern. The hyperfine interaction parameters for the all subspectra components confirm existence iron Fe{sup 3+} only in the investigated material.

  10. Grain size dependent phase stabilities and presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} piezoceramics

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Ashutosh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2015-04-14

    Results of the room temperature structural studies on (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} ceramics using Rietveld analysis of the powder x-ray diffraction data in the composition range 0.28 ≤ x ≤ 0.45 are presented. The morphotropic phase boundary region exhibits coexistence of monoclinic (space group Pm) and tetragonal (space group P4 mm) phases in the composition range 0.33 ≤ x ≤ 0.40. The structure is nearly single phase monoclinic (space group Pm) in the composition range 0.28 ≤ x ≤ 0.32. The structure for the compositions with x ≥ 0.45 is found to be predominantly tetragonal with space group P4 mm. Rietveld refinement of the structure rules out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier authors. The Rietveld structure analysis for the sample x = .35 calcined at various temperatures reveals that phase fraction of the coexisting phases in the morphotropic phase boundary region varies with grain size. The structural parameters of the two coexisting phases also change slightly with changing grain size.

  11. Effect of La-substitution on structural, dielectric and electrical properties of (Bi{sub 0.5}Pb{sub 0.5}) (Fe{sub 0.5}Zr{sub 0.25}Ti{sub 0.25})O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Panda, Niranjan [Driems Engineering College, Department of Physics, Cuttack (India); Pattanayak, Samita [College of Engineering and Technology, Department of Physics, Bhubaneswar (India); Choudhary, R.N.P. [Siksha ' O' Anusandhan University, Department of Physics, Bhubaneswar (India); Kumar, Ashok [National Physical Laboratory (CSIR), New Delhi (India)

    2016-09-15

    As lead zirconium titanate and bismuth ferrite (BFO), members of perovskite family, have high dielectric constant and ferroelectric/ferromagnetic phase transition temperature, they are used for many potential applications including random access memory, sensors. The present work describes the modifications in the ferroelectric behaviour of PZT doped BFO due to substitution of few molar percent of La on Fe-site. A thorough comparative investigation of the frequency and temperature response of dielectric permittivity, dielectric loss, electric modulus, complex impedance and ferroelectric properties of Bi{sub 0.5}Pb{sub 0.5}[Fe{sub (0.5-x)}La{sub x}(Zr{sub 0.25}Ti{sub 0.25})] O{sub 3}, where x = 0.0, 0.1, 0.2, 0.3 (hence forth called as BFPZLTO) compounds were studied in a wide frequency range 10 kHz to 1 MHz at temperature range 25-400 C using ac impedance spectroscopy and electric modulus analysis. The structural analysis of compound revealed the tetragonal phase with space group P4 mm at room temperature. Cole-Cole plots are used for interpretation of relaxation mechanism in the materials. The materials especially the compound with x = 0.3 found more suitable to be used in transducers, RAMs, flip-flop memories, etc., for electronics applications. (orig.)

  12. Residual nuclide formation in 206,207,208,nat-Pb and 209-Bi induced by 0.04-2.6 GeV Protons as well as in 56-Fe induced by 0.3-2.6 GeV Protons

    CERN Document Server

    Titarenko, Yu E; Titarenko, A Yu; Butko, M A; Pavlov, K V; Tikhonov, R S; Florya, S N; Mashnik, S G; Ignatyuk, A V; Gudowski, W

    2007-01-01

    5972 independent and cumulative yields of radioactive residuals nuclei have been measured in 55 thin 206,207,208,nat-Pb and 209-Bi targets irradiated by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV protons. Besides, 219 yields have been measured in 0.3, 0.5, 0.75, 1.0, 1.5, and 2.6 GeV proton-irradiated 56-Fe target. The protons were extracted from the ITEP U-10 synchrotron. The measured data are compared with experimental results obtained elsewhere and with theoretical calculations by LAHET, MCNPX, CEM03, LAQGSM03, CASCADE, CASCADO, and LAHETO codes. The predictive power was found to be different for each of the codes tested, but was satisfactory on the whole in the case of spallation products. At the same time, none of the codes can de-scribe well the product yields throughout the whole product mass range, and all codes must be further improved.

  13. Effects of ZnO addition on mechanical properties of Bi{sub 1.84}Pb{sub 0.34}Sr{sub 1.91}Ca{sub 2.03}Cu{sub 3.06}O{sub 10} prepared by a wet technique

    Energy Technology Data Exchange (ETDEWEB)

    Karaca, I. [Department of Physics, Faculty of Science and Arts, Nigde University, 51200 Nigde (Turkey)], E-mail: ikaraca38@hotmail.com; Uzun, O.; Koelemen, U.; Yilmaz, F. [Department of Physics, Faculty of Science and Arts, Gaziosmanpasa University, 60240 Tokat (Turkey); Sahin, O. [Department of Physics, Faculty of Science and Arts, Mustafa Kemal University, 31034 Hatay (Turkey)

    2009-05-12

    In this study, ZnO molar wt% 0, 5, 10, 20, 30, and 50 added Bi{sub 1.84}Pb{sub 0.34}Sr{sub 1.91}Ca{sub 2.03}Cu{sub 3.06}O{sub 10} superconductors were prepared by wet technique. The experimental works consist of powder X-ray diffraction (XRD) for phase analyses and c-axes parameters, scanning electron microscopy (SEM) for microstructure examination, and microhardness measurements for mechanical properties. These measurements showed that Zn-added material, in comparison with the pure sample, had increased c-axes parameters and decreased grain size. In addition, the experimental results of microhardness measurements were analyzed using Oliver-Pharr model. It was observed that the change of indentation hardness (H{sub IT}) and reduced elastic modulus (E{sub r}) values showed an increasing trend with ZnO addition and exhibited peak load dependence (i.e., indentation size effect (ISE))

  14. Étude de la production inclusive de $J/\\psi$ dans les collisions Pb-Pb à $\\sqrt{s_{_{\\rm NN}}}=2,76$ TeV avec le spectromètre à muons de l'expérience ALICE au LHC

    CERN Document Server

    Lardeux, Antoine

    The quantum chromodynamics theory predicts the existence of a deconfined state of matter called Quark Gluon Plasma (QGP). Experimentally, the formation of a QGP is expected under the extreme conditions of temperature and density reached in ultra-relativistic heavy-ion collisions. Many observables were proposed to observe and characterize indirectly such a state of matter. In particular, the phenomena of suppression and (re)combination of the $J/\\psi$ meson in the QGP are extensively studied. This thesis presents the analysis of the inclusive production of $J/\\psi$ in Pb-Pb collisions, at a center of mass energy $\\sqrt{s_{_{\\rm NN}}}=2.76$ TeV, detected with the ALICE muon spectrometer at the LHC. From the high statistics of events collected during 2011 data taking, the $J/\\psi$ nuclear modification factor was measured as a function of transverse momentum, rapidity and collision centrality. The $J/\\psi$ mean transverse momentum was also measured as a function of centrality. The predictions of theoretical...

  15. Time evolution of relativistic d + Au and Au + Au collisions

    CERN Document Server

    Wolschin, G; Mizoguchi, T; Suzuki, N; Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi; Wolschin, Georg

    2006-01-01

    The evolution of charged-particle production in collisions of heavy ions at relativistic energies is investigated as function of centrality in a nonequilibrium-statistical framework. Precise agreement with recent d + Au and Au + Au data at sqrt(s_NN) = 200 GeV is found in a Relativistic Diffusion Model with three sources for particle production. Only the midrapidity source comes very close to local equilibrium, whereas the analyses of the overall pseudorapidity distributions show that the systems remain far from statistical equilibrium.

  16. DIRECT PROTON DECAY FROM THE GAMOW-TELLER RESONANCE IN BI-208

    NARCIS (Netherlands)

    AKIMUNE, H; DAITO, [No Value; FUJITA, Y; FUJIWARA, M; GREENFIELD, MB; HARAKEH, MN; INOMATA, T; JANECKE, J; KATORI, K; NAKAYAMA, S; SAKAI, H; SAKEMI, Y; TANAKA, M; YOSOI, M

    1995-01-01

    Spin-isospin excitations in Bi-208 have been investigated using the Pb-208(He-3,t)Bi-208 reaction at and near theta approximate to 0 degrees at E(He-3)=450 MeV. The microscopic structure of the Gamow-Teller resonance (GTR), the isobaric analog state (IAS), and the spin-flip dipole (Delta L = 1) reso

  17. Po-210 and Pb-210 as atmospheric tracers and global atmospheric Pb-210 fallout: a Review

    Energy Technology Data Exchange (ETDEWEB)

    Baskaran, M., E-mail: Baskaran@wayne.ed [Department of Geology, Wayne State University, Detroit, MI-48202 (United States)

    2011-05-15

    Over the past {approx}5 decades, the distribution of {sup 222}Rn and its progenies (mainly {sup 210}Pb, {sup 210}Bi and {sup 210}Po) have provided a wealth of information as tracers to quantify several atmospheric processes that include: i) source tracking and transport time scales of air masses; ii) the stability and vertical movement of air masses iii) removal rate constants and residence times of aerosols; iv) chemical behavior of analog species; and v) washout ratios and deposition velocities of aerosols. Most of these applications require that the sources and sink terms of these nuclides are well characterized. Utility of {sup 210}Pb, {sup 210}Bi and {sup 210}Po as atmospheric tracers requires that data on the {sup 222}Rn emanation rates is well documented. Due to low concentrations of {sup 226}Ra in surface waters, the {sup 222}Rn emanation rates from the continent is about two orders of magnitude higher than that of the ocean. This has led to distinctly higher {sup 210}Pb concentrations in continental air masses compared to oceanic air masses. The highly varying concentrations of {sup 210}Pb in air as well the depositional fluxes have yielded insight on the sources and transit times of aerosols. In an ideal enclosed air mass (closed system with respect to these nuclides), the residence times of aerosols obtained from the activity ratios of {sup 210}Pb/{sup 222}Rn, {sup 210}Bi/{sup 210}Pb, and {sup 210}Po/{sup 210}Pb are expected to agree with each other, but a large number of studies have indicated discordance between the residence times obtained from these three pairs. Recent results from the distribution of these nuclides in size-fractionated aerosols appear to yield consistent residence time in smaller-size aerosols, possibly suggesting that larger size aerosols are derived from resuspended dust. The residence times calculated from the {sup 210}Pb/{sup 222}Rn, {sup 210}Bi/{sup 210}Pb, and {sup 210}Po/{sup 210}Pb activity ratios published from 1970&apos

  18. In situ stress and nanogravimetric measurements during underpotential deposition of bismuth on (111)-textured Au.

    Science.gov (United States)

    Stafford, G R; Bertocci, U

    2006-08-10

    The surface stress associated with the underpotential deposition (upd) of bismuth on (111)-textured Au is examined, using the wafer curvature method, in acidic perchlorate and nitrate supporting electrolyte. The surface stress is correlated to Bi coverage by independent nanogravimetric measurements using an electrochemical quartz crystal nanobalance. The mass increase measured in the presence of perchlorate is consistent with the (2 x 2) and (p x square root 3)-2Bi adlayers reported in the literature. ClO(4)(-) does not play a significant role in the upd process. The complete Bi monolayer causes an overall surface stress change of about -1.4 N m(-1). We attribute this compressive stress to the formation of Bi-Au bonds which partially satisfy the bonding requirements of the Au surface atoms, thereby reducing the tensile surface stress inherent to the clean Au surface. At higher Bi coverage, an additional contribution to the compressive stress is due to the electrocompression of the (p x square root 3)-2Bi adlayer. In nitric acid electrolyte, NO(3)(-) coadsorbs with Bi over the entire upd region but has little fundamental impact on adlayer structure and stress.

  19. Phase stability and grain growth in an Ag/Bi-2223 composite conductor prepared using fine-grained Bi-2223 as a precursor.

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, N. N.

    1998-09-17

    We have investigated the stability and microstructural transformability of the Bi-2223 phase in a silver-sheathed monofilament composite tape fabricated using fine-grained Bi{sub 1.7}Pb{sub 0.3}Sr{sub 1.9}Ca{sub 2.0}-Cu{sub 3.0}O{sub y} (Bi-2223) as the precursor powder. The fully formed Bi-2223 precursor was prepared using established procedures. The purpose of this study was to explore the prospects for growing textured, large-grain-size Bi-2223 from the fine-grained precursor by process parameter perturbations. These perturbations included thermal ramp up variations, programmed heat treatment temperature and oxygen pressure fluctuations, and parameter manipulations during cool-down. Our results show that the types of heat treatments used in conventional oxide-powder-in-tube (OPIT) processing do not facilitate Bi-2223 grain growth when the precursor powder is preconcerted Bi-2223. We also observed that the Bi-2223 partially. decomposed during conventional thermal ramp-up in 0.075 atm O{sub 2}, but that this decomposition can be inhibited by ramping up in a reduced oxygen pressure. A pathway was found for back-reacting the fine-grained Bi-2223 (to Bi-2212, Bi-2201 and nonsuperconducting secondary phases), then reforming large-grained Bi-2223 in a colony microstructure having some distinct differences from that produced during conventional OPIT processing.

  20. Synthesis of 4H/fcc-Au@Metal Sulfide Core-Shell Nanoribbons.

    Science.gov (United States)

    Fan, Zhanxi; Zhang, Xiao; Yang, Jian; Wu, Xue-Jun; Liu, Zhengdong; Huang, Wei; Zhang, Hua

    2015-09-02

    Although great advances on the synthesis of Au-semiconductor heteronanostructures have been achieved, the crystal structure of Au components is limited to the common face-centered cubic (fcc) phase. Herein, we report the synthesis of 4H/fcc-Au@Ag2S core-shell nanoribbon (NRB) heterostructures from the 4H/fcc Au@Ag NRBs via the sulfurization of Ag. Remarkably, the obtained 4H/fcc-Au@Ag2S NRBs can be further converted to a novel class of 4H/fcc-Au@metal sulfide core-shell NRB heterostructures, referred to as 4H/fcc-Au@MS (M = Cd, Pb or Zn), through the cation exchange. We believe that these novel 4H/fcc-Au@metal sulfide NRB heteronanostructures may show some promising applications in catalysis, surface enhanced Raman scattering, solar cells, photothermal therapy, etc.

  1. Strain-Mediated Interfacial Dynamics during Au–PbS Core–Shell Nanostructure Formation

    KAUST Repository

    Niu, Kai-Yang

    2016-05-23

    An understanding of the hierarchical nanostructure formation is of significant importance for the design of advanced functional materials. Here, we report the in situ study of lead sulfide (PbS) growth on gold (Au) nanorod seeds using liquid cell transmission electron microscopy (TEM). By tracking the formation dynamics of Au-PbS core-shell nanoparticles, we found the preferential heterogeneous nucleation of PbS on the ends of a Au nanorod prior to the development of a complete PdS shell. During PbS shell growth, drastic sulfidation of Au nanorod was observed, leading to large volume shrinkage (up to 50%) of the initial Au nanorod seed. We also captured intriguing wavy interfacial behavior, which can be explained by our DFT calculation results that the local strain gradient at the core-shell interface facilitates the mass transport and mediates reversible phase transitions of AuAu2S during the PbS shell growth. © 2016 American Chemical Society.

  2. Evaluation of the uncertainty for the efficiency curve determination of {sup 210}Pb by liquid scintillation; Avaliacao da incerteza para a curva de eficiencia da determinacao de {sup 210}Pb por cintilacao liquida

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, C.S.; Sousa, W.O.; Dantas, B.M., E-mail: camilla@ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Methodologies for the evaluation of uncertainties associated with the determination of the efficiency curve of {sup 210}Pb by liquid scintillation counting (LSC) are presented. No statistical difference were found when compared the uncertainties of the curves that represented the counting net before and after the secular equilibrium between {sup 210}Pb and {sup 210}Bi, nether when compared the curves when counting only {sup 210}Pb and the curve with the total count of {sup 210}Pb and {sup 210}Bi, for the same time interval after precipitation. (author)

  3. Discussion on the ore-controlling factors and metallogenesis of Yanshan Au, Ag, Pb, Zn deposits in the volcanic rock of Southeastern Zhejiang%浙东南火山岩地区燕山期金银铅锌矿床控矿因素及成因探讨

    Institute of Scientific and Technical Information of China (English)

    何元才; 俞跃平

    2011-01-01

    Based on the study of ore - controlling factors and metallogenesis, it was concluded in this paper that the Au, Ag, Pb, Zn deposits related to Yanshan volcanic rock in Southeastern Zhejiang were meso - epithemal deposits, and the hydrothermal fluid was originated from rainwater, and ore - forming materials were derived from wall rock as well. So water source and heat source were the key factors in the ore - forming process. Water played a special effect on the ore - forming process and deposits distributed because of continental margin of volcanic activities. It was concluded that water - bearing faulted structure and sedimentary formation were the optimistical section for large - scale deposit.%文章对浙东南火山岩地区燕山期金银铅锌矿床的控矿因素和成因进行了分析研究,认为浙东南燕山期金银铅锌矿属于浅成中低温热液矿床,其热液来源于雨水,成矿物质来源于围岩,水源和热源在成矿过程中起着决定性的作用,陆缘火山活动的地质背景决定了水在成矿作用中的特殊作用,决定了矿床的空间分布,含水的断裂构造和沉积建造是寻找大型矿床的最有利地段.

  4. Late Cretaceous porphyry Cu and epithermal Cu-Au association in the Southern Panagyurishte District, Bulgaria: the paired Vlaykov Vruh and Elshitsa deposits

    Science.gov (United States)

    Kouzmanov, Kalin; Moritz, Robert; von Quadt, Albrecht; Chiaradia, Massimo; Peytcheva, Irena; Fontignie, Denis; Ramboz, Claire; Bogdanov, Kamen

    2009-08-01

    Vlaykov Vruh-Elshitsa represents the best example of paired porphyry Cu and epithermal Cu-Au deposits within the Late Cretaceous Apuseni-Banat-Timok-Srednogorie magmatic and metallogenic belt of Eastern Europe. The two deposits are part of the NW trending Panagyurishte magmato-tectonic corridor of central Bulgaria. The deposits were formed along the SW flank of the Elshitsa volcano-intrusive complex and are spatially associated with N110-120-trending hypabyssal and subvolcanic bodies of granodioritic composition. At Elshitsa, more than ten lenticular to columnar massive ore bodies are discordant with respect to the host rock and are structurally controlled. A particular feature of the mineralization is the overprinting of an early stage high-sulfidation mineral assemblage (pyrite ± enargite ± covellite ± goldfieldite) by an intermediate-sulfidation paragenesis with a characteristic Cu-Bi-Te-Pb-Zn signature forming the main economic parts of the ore bodies. The two stages of mineralization produced two compositionally different types of ores—massive pyrite and copper-pyrite bodies. Vlaykov Vruh shares features with typical porphyry Cu systems. Their common geological and structural setting, ore-forming processes, and paragenesis, as well as the observed alteration and geochemical lateral and vertical zonation, allow us to interpret the Elshitsa and Vlaykov Vruh deposits as the deep part of a high-sulfidation epithermal system and its spatially and genetically related porphyry Cu counterpart, respectively. The magmatic-hydrothermal system at Vlaykov Vruh-Elshitsa produced much smaller deposits than similar complexes in the northern part of the Panagyurishte district (Chelopech, Elatsite, Assarel). Magma chemistry and isotopic signature are some of the main differences between the northern and southern parts of the district. Major and trace element geochemistry of the Elshitsa magmatic complex are indicative for the medium- to high-K calc-alkaline character of

  5. Charmonium production in Pb-Pb collisions

    CERN Document Server

    De Marco, N; Alessandro, B; Alexa, C; Arnaldi, R; Astruc, J; Atayan, M; Baglin, C; Baldit, A; Bedjidian, Marc; Bellaiche, F G; Beolè, S; Boldea, V; Bordalo, P; Bussière, A; Capelli, L; Caponi, V; Casagrande, L; Castor, J I; Chambon, T; Chaurand, B; Chevrot, I; Cheynis, B; Chiavassa, E; Cicalò, C; Comets, M P; Constans, N; Constantinescu, S; Cruz, J; De Falco, A; De Marco, N; Dellacasa, G; Devaux, A; Dita, S; Drapier, O; Ducroux, L; Espagnon, B; Fargeix, J; Filippov, S N; Fleuret, F; Force, P; Gallio, M; Gavrilov, Yu K; Gerschel, C; Giubellino, P; Golubeva, M B; Gonin, M; Grigorian, A A; Grossiord, J Y; Guber, F F; Guichard, A; Gulkanian, H R; Hakobyan, R S; Haroutunian, R; Idzik, M; Jouan, D; Karavitcheva, T L; Kluberg, L; Kurepin, A B; Le Bornec, Y; Lourenço, C; Macciotta, P; MacCormick, M; Marzari-Chiesa, A; Masera, M; Masoni, A; Mehrabyan, S S; Monteno, M; Mourgues, S; Musso, A; Ohlsson-Malek, F; Petiau, P; Piccotti, A; Pizzi, J R; Prado da Silva, W L; Puddu, G; Quintans, C; Racca, C; Ramello, L; Ramos, S; Rato-Mendes, P; Riccati, L; Romana, A; Ropotar, I; Saturnini, P; Scomparin, E; Serci, S; Shahoyan, R; Silva, S; Sitta, M; Soave, C; Sonderegger, P; Tarrago, X; Topilskaya, N S; Usai, G L; Vercellin, Ermanno; Villatte, L; Willis, N

    2000-01-01

    The NA50 Collaboration studies the J/psi, psi' and Drell-Yan production via their dimuon decay in Pb-Pb interactions at 158 GeV per nucleon at the CERN SPS: the most recent results on charmonium production are presented here.

  6. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... States Environmental Protection Agency Search Search Lead (Pb) Air Pollution Share Facebook Twitter Google+ Pinterest Contact Us As ... and protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Lead Air Pollution Basics How does lead get ...

  7. Enhancing average ZT in pristine PbSe by over-stoichiometric Pb addition

    Science.gov (United States)

    Wu, Chao-Feng; Wei, Tian-Ran; Li, Jing-Feng

    2016-10-01

    PbSe is an inexpensive alternative for PbTe as a mid-temperature thermoelectric material, but few investigations have been reported about its intrinsic properties despite recent efforts on doping techniques. In this work, pristine PbSe bulk materials were synthesized by a process combining mechanical alloying and spark plasma sintering, which is increasingly used for processing thermoelectric materials, and their electrical and thermal transport properties as well as thermoelectric performance were investigated in a wide temperature range. A maximum ZT ˜0.83 was obtained at 673 K in nominal composition PbSe + 3 or 4 at. % Pb, leading to nearly 50% enhancement from reported n-type pristine PbSe, mainly benefitting from the improved electrical performance. Furthermore, the potential thermoelectric efficiency was also improved due to the enhanced low-temperature performance, showing a high average ZT of 0.6 that is even comparable to that of commercial n-type Bi2Te3 materials.

  8. The effect of sintering temperature on the intergranular properties and weak link behavior of Bi2223 superconductors

    Directory of Open Access Journals (Sweden)

    P. Kameli

    2006-03-01

    Full Text Available  A systematic study of the intergranular properties of (Bi,Pb2 Sr2 Ca2 Cu3 Oy (Bi2223 polycrystalline samples has been done using the electrical resistivity and AC susceptibility techniques. In this study, we have prepared a series of Bi2223 samples with different sintering temperatures. The XRD results show that by increasing the sintering temperature up to 865° c , the Bi2212 phase fraction decreases. It was found that the Bi2212 phase on the grain boundaries is likely to play the role of the weak links and consequently reduces the intergranular critical current densities.

  9. Critical current densities in Bi-2223 sinter forgings.

    Energy Technology Data Exchange (ETDEWEB)

    Balachandran, U.; Fisher, B. L.; Goretta, K. C.; Harris, N. C.; Murayama, N.

    1999-07-23

    (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Bi-2223) bars, prepared by sinter forging, exhibited good phase purity and strong textures with the c axes of the Bi-2223 grains parallel to the forging direction. The initial zero-field critical current density (J{sub c}) of the bars was 10{sup 3} A/cm{sup 2}, but because the forged bars were uncoated, this value decreased with repeated thermal cycling. J{sub c} as a function of applied magnetic field magnitude and direction roughly followed the dependencies exhibited by Ag-sheathed Bi-2223 tapes, but the forged bars were more strongly dependent on field strength and less strongly dependent on field angle.

  10. Alpha decay of {sup 181}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Henderson, D.J.; Hermann, R. [and others

    1995-08-01

    The {alpha}-decay energy of {sup 181}Pb was measured as 7211(10) keV and 7044(15). In the first study the isotope was produced in {sup 90}Zr bombardments of {sup 94}Mo and, after traversing a velocity filter, implanted in a position-sensitive Si detector; no half life for {sup 181}Pb was reported. In the second study the isotope was produced in {sup 40}Ca bombardments of {sup 144}Sm and transported to a position in front of a Si(Au) surface barrier detector with a fast He-gas-jet capillary system; an estimate of 50 ms was determined for the {sup 181}Pb half life. Recently we investigated {sup 181}Pb {alpha} decay at ATLAS as part of a survey experiment in which a l-pnA beam of 400-MeV {sup 92}Mo was used to irradiate targets of {sup 89}Y, {sup 90,92,94}Zr, and {sup 92}Mo to examine yields for one- and two-nucleon evaporation products from symmetric cold-fusion reactions. Recoiling nuclei of interest were passed through the Fragment Mass Analyzer and implanted in a double-sided silicon strip detector for {alpha}-particle assay. With the {sup 90}Zr target we observed a group at 7065(20) keV which was correlated with A = 181 recoils and had a half life of 45(20) ms. Our new results for {sup 181}Pb therefore agreed with those of the second study. There was no indication in the {sup 90}Zr + {sup 92}Mo data of the 7211(10)-keV {alpha} particles seen by Keller et al. The interested reader is referred to the 1993 atomic mass evaluation wherein the input {alpha}-decay energies and resultant masses of the light Pb isotopes (including {sup 181}Pb) are discussed.

  11. Collective flow in Au + Au collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, H.G.; EOS Collaboration

    1994-05-01

    Based on a preliminary sample of Au + Au collisions in the EOS time projection chamber at the Bevalac, we study sideward flow as a function of bombarding energy between 0.25A GeV and 1.2A GeV. We focus on the increase in in-plane transverse momentum per nucleon with fragment mass. We also find event shapes to be close to spherical in the most central collisions, independent of bombarding energy and fragment mass up to {sup 4}He.

  12. Role of vanadium in Bi-2223 ceramics

    Indian Academy of Sciences (India)

    D R Mishra; S V Sharma; R G Sharma

    2000-02-01

    The effect of substitution of vanadium in Bi1.6Pb0.4Sr2Ca2Cu3O ceramic at Bi and Cu sites has been investigated for the resistivity, a.c. susceptibility, XRD and a.c. magnetization studies. Enhancement in for the smaller concentrations of V at either of the two sites was observed which followed an expected lattice distortion and decrease in for higher V concentrations. V plays a role of substituting element more than just a sintering agent as reflected in the more rapid decrease in at Cu-site and further in the magnetization values that are higher compared to the values at the Bisite. It indicates higher magnetization scattering at the Cu site. The results were explained keeping in mind the liquid phase mechanism behind the formation of the 2223 phase and the possibility of magnetic scattering.

  13. Resonance energy transfer between fluorescent BSA protected Au nanoclusters and organic fluorophores.

    Science.gov (United States)

    Raut, Sangram; Rich, Ryan; Fudala, Rafal; Butler, Susan; Kokate, Rutika; Gryczynski, Zygmunt; Luchowski, Rafal; Gryczynski, Ignacy

    2014-01-01

    Bovine serum albumin (BSA) protected nanoclusters (Au and Ag) represent a group of nanomaterials that holds great promise in biophysical applications due to their unique fluorescence properties and lack of toxicity. These metal nanoclusters have utility in a variety of disciplines including catalysis, biosensing, photonics, imaging and molecular electronics. However, they suffer from several disadvantages such as low fluorescence quantum efficiency (typically near 6%) and broad emission spectrum (540 nm to 800 nm). We describe an approach to enhance the apparent brightness of BSA Au clusters by linking them with a high extinction donor organic dye pacific blue (PB). In this conjugate PB acts as a donor to BSA Au clusters and enhances its brightness by resonance energy transfer (RET). We found that the emission of BSA Au clusters can be enhanced by a magnitude of two-fold by resonance energy transfer (RET) from the high extinction donor PB, and BSA Au clusters can act as an acceptor to nanosecond lifetime organic dyes. By pumping the BSA Au clusters using a high extinction donor, one can increase the effective brightness of less bright fluorophores like BSA Au clusters. Moreover, we prepared another conjugate of BSA Au clusters with the near infrared (NIR) dye Dylight 750 (Dy750), where BSA Au clusters act as a donor to Dy750. We observed that BSA Au clusters can function as a donor, showing 46% transfer efficiency to the NIR dye Dy750 with a long lifetime component in the acceptor decay through RET. Such RET-based probes can be used to prevent the problems of a broad emission spectrum associated with the BSA Au clusters. Moreover, transferring energy from BSA Au clusters to Dy750 will result in a RET probe with a narrow emission spectrum and long lifetime component which can be utilized in imaging applications.

  14. Direct observation of atomic columns in a Bi-2223 polycrystal by aberration-corrected STEM using a low accelerating voltage

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Takuro, E-mail: nagai.takuro@nims.go.jp [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Haruta, Mitsutaka [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kikuchi, Masashi [Sumitomo Electric Industries Ltd., Konohana-ku, Osaka 554-0024 (Japan); Zhang, Weizhu; Takeguchi, Masaki; Kimoto, Koji [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan)

    2014-05-15

    Highlights: • We investigate a Ag-sheathed Bi-2223 wire by low-voltage aberration-corrected STEM. • Atomic displacements enable each layer to be continuous at edge grain boundaries. • The grains are terminated with deficient (Bi,Pb)–O layers at the other boundaries. • EELS mapping visualizes atomic columns in the intergrowth of Bi-2212 and 2234 phases. • HAADF analysis shows modulation of the occupancy of the (Bi,Pb) sites along [1 1 0]. - Abstract: Aberration correction in scanning transmission electron microscopy (STEM) enables an atomic-scale probe size of ∼0.1 nm at a low accelerating voltage of 80 kV that avoids knock-on damage in materials including light elements such as oxygen. We used this advanced method of microscopy to directly observe atomic columns in a (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+δ} (Bi-2223) superconducting wire produced by a powder-in-tube method. Using the atomic-number (Z) contrast mechanism, incoherent high-angle annular dark-field (HAADF) imaging clearly showed the atomic columns. Atomic displacements toward the boundary with a maximum magnitude of ∼0.26 nm enable each atomic layer to be continuous at edge grain boundaries (EGBs). The grains tend to be terminated with deficient (Bi,Pb)–O single layers at c-axis twist boundaries (TWBs) and small-angle asymmetrical tilt boundaries (ATBs); a quantitative HAADF analysis showed that the occupancies of the (Bi,Pb) sites around these boundaries are ∼0.66 and ∼0.72, respectively. Electron energy-loss spectroscopy (EELS) mapping successfully visualized atomic columns in the half-unit cell intergrowth of (Bi,Pb){sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} (Bi-2212) and (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 3}Cu{sub 4}O{sub 12+δ} (Bi-2234) phases. Furthermore, the HAADF analysis indicated that the occupancy of the (Bi,Pb) sites is modulated between ∼0.88 and 1.0 along the diagonal direction of the primitive perovskite cell with the same period as the structural modulation.

  15. The origin of photovoltaic responses in BiFeO3 multiferroic ceramics.

    Science.gov (United States)

    Tu, C-S; Hung, C-M; Schmidt, V H; Chien, R R; Jiang, M-D; Anthoninappen, J

    2012-12-12

    Multiferroic BiFeO(3) (BFO) ceramics with electrodes of indium tin oxide (ITO) and Au thin films exhibit significant photovoltaic effects under near-ultraviolet illumination (λ = 405 nm) and show strong dependences on light wavelength, illumination intensity, and sample thickness. The correlation between photovoltaic responses and illumination intensity can be attributed to photo-excited and thermally generated charge carriers in the interface depletion region between BFO ceramic and ITO thin film. A theoretical model is developed to describe the open-circuit photovoltage and short-circuit photocurrent density as a function of illumination intensity. This model can be applied to the photovoltaic effects in p-n junction type BFO thin films and other systems. The BFO ceramic exhibits stronger photovoltaic responses than the ferroelectric Pb(1-x)La(x)(Zr(y)Ti(1-y))(1-x/4)O(3) (PLZT) ceramics under near-ultraviolet illumination. Comparisons are made with other systems and models for the photovoltaic effect.

  16. Catalytic Activity of Mono- and Bi-Metallic Nanoparticles Synthesized via Microemulsions

    Directory of Open Access Journals (Sweden)

    Ramona Y.G. König

    2014-07-01

    Full Text Available Water-in-oil (w/o microemulsions were used as a template for the synthesis of mono- and bi-metallic nanoparticles. For that purpose, w/o-microemulsions containing H2PtCl6, H2PtCl6 + Pb(NO32 and H2PtCl6 + Bi(NO3, respectively, were mixed with a w/o-microemulsion containing the reducing agent, NaBH4. The results revealed that it is possible to synthesize Pt, PtPb and PtBi nanoparticles of ~3–8 nm in diameter at temperatures of about 30°C. The catalytic properties of the bimetallic PtBi and PtPb nanoparticles were studied and compared with monometallic platinum nanoparticles. Firstly, the electrochemical oxidation of formic acid to carbon monoxide was investigated, and it was found that the resistance of the PtBi and PtPb nanoparticles against the catalyst-poisoning carbon monoxide was significantly higher compared to the Pt nanoparticles. Secondly, investigating the reduction of 4-nitrophenol to 4-aminophenol,we found that the bimetallic NPs are most active at 23 °C, while the order of the activity changes at higher temperatures, i.e., that the Pt nanoparticles are the most active ones at 36 and 49 °C. Furthermore, we observed a strong influence of the support, which was either a polymer or Al2O3. Thirdly, for the hydrogenation of allylbenzene to propylbenzene, the monometallic Pt NPs turned out to be the most active catalysts, followed by the PtPb and PtBi NPs. Comparing the two bimetallic nanoparticles, one sees that the PtPb NPs are significantly more active than the respective PtBi NPs.

  17. Synthesis, characterization and electrical properties of sol-gel derived 0.63Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-0.37PbTiO{sub 3} high-T{sub c} piezoelectric ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ji Xun [Institute of Electro Ceramics and Devices, School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zuo Ruzhong, E-mail: piezolab@hfut.edu.cn [Institute of Electro Ceramics and Devices, School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Qi Shishun; Liu Longdong [Institute of Electro Ceramics and Devices, School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China)

    2012-06-15

    The nano-scaled powders of a high Curie temperature piezoelectric system with a composition of 0.63Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-0.37PbTiO{sub 3} (0.63BMT-0.37PT) have been synthesized via a citrate sol-gel method. The thermal decomposition process of the as-prepared xerogel was investigated through the thermo-gravitometry and differential scanning calorimetry. The lattice structure of the powders as the function of heat-treatment temperatures was explored by using X-ray diffraction, Fourier-transform infra-red and Raman spectra. The results indicated that the transparent gel could be obtained via the chelate reaction of citric acid with ethylene glycol and ethanolamine assist. Gels can be transformed into crystallite powders with a single-phase perovskite structure when heat-treated at 600 Degree-Sign C for 3 h, much lower than that of traditional solid-state reaction method. The sol-gel derived 0.63BMT-0.37PT ceramics sintered at 1020 Degree-Sign C exhibit excellent dielectric, ferroelectric and piezoelectric properties of T{sub c} = 463 Degree-Sign C, {epsilon}{sub 33}{sup T}=1208, tan {delta} = 0.063, P{sub r} = 22.1 {mu}C cm{sup -2} and d{sub 33} = 230 pC N{sup -1}. Moreover, a small amount of Mn{sup 2+} doping could cause the reduced leakage current and slightly increased T{sub c} values. - Highlights: Black-Right-Pointing-Pointer We synthesize BMT-PT superfine powders of a high Curie temperature piezoelectric system of via citrate sol-gel method. Black-Right-Pointing-Pointer We characterize the powders by means of DSC, XRD, FT-IR, Raman and TEM. Black-Right-Pointing-Pointer Sol-gel derived BMT-PT ceramics sintered at 1020 Degree-Sign C exhibit optimum electrical properties.

  18. Modification of photosensing property of CdS–Bi{sub 2}S{sub 3} bi-layer by thermal annealing and swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, Shaheed U.; Siddiqui, Farha Y. [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India); Singh, Fouran; Kulriya, Pawan K. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Phase, D.M. [UGC DAE Consortium for Scientific Research, Khandwa Road, Indore 452017 (India); Sharma, Ramphal, E-mail: ramphalsharma@yahoo.com [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India)

    2016-02-01

    The CdS–Bi{sub 2}S{sub 3} bi-layer thin films have been deposited on Indium Tin Oxide (ITO) glass substrates at room temperature by Chemical Bath Deposition Technique (CBD) and bi-layer thin films were annealed in air atmosphere for 1 h at 250 {sup °}C. The air annealed sample was irradiated using Au{sup 9+} ions at the fluence 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. Effects of Swift Heavy Ion (SHI) irradiation on CdS–Bi{sub 2}S{sub 3} bi-layer thin films were studied. The results are explained on the basis annealing and high electronic excitation, using X-ray diffraction (XRD), Selective Electron Area Diffraction (SEAD), Atomic Force Microscopy (AFM), Raman Spectroscopy, UV spectroscopy and I–V characteristics. The photosensing property after illumination of visible light over the samples is studied. These as-deposited, annealed and irradiated bi-layer thin films are used to sense visible light at room temperature. - Graphical abstract: Schematic illustration of CdS–Bi{sub 2}S{sub 3} bi-layer thin film (a) As-deposited (b) Annealed (c) irradiated sample respectively (d) Model of bi-layer photosensor device (e) Graph of illumination intensity verses photosensitivity. - Highlights: • CdS–Bi{sub 2}S{sub 3} bi-layer thin film prepared at room temperature. • Irradiated using Au{sup 9+} ions at the fluence of 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. • Study of modification induced by irradiations. • Study of Photosensitivity after annealing and irradiation.

  19. Geology, mineralogy and fluid inclusion data from the Arapucan Pb Zn Cu Ag deposit, Canakkale, Turkey

    Science.gov (United States)

    Orgün, Yüksel; Gültekin, Ali Haydar; Onal, Ayten

    2005-07-01

    The Arapucan Pb-Zn-Cu-Ag deposit occurs as hydrothermal veins in diabase and altered Triassic metasandstones adjacent to calc-alkaline intrusive igneous rocks. The deposit is an important commercial source of base metal in northwestern Turkey. Potential by-products are silver and gold. The geology of the area includes a Paleozoic metamorphic basement, Triassic sedimentary rocks with carbonate blocks, Tertiary granitoids and Neogene volcanics. The mineral assemblage includes galena, quartz, calcite, sphalerite, chalcopyrite and pyrite as well as minor bismuthinite, tetrahedrite, pyrolusite, hematite, scheelite, malachite, magnetite, limonite and rutile. Silver is associated with tetrahedrite. Early hydrothermal activity was responsible for the formation of three hypogene alteration types of decreasing intensity: silicification, sericitization and argillic alteration. These alteration styles show a rough spatial zonation. The ore stage clearly postdates hydrothermal alteration, as indicated by the occurrence of ore minerals in vuggy cavities and fractures in silica bodies. The deposit contains evidence of at least two periods of hypogene mineralization separated by a period of faulting. In addition to Pb, Zn, Cu, Ag and Au, the ores contain substantial quantities of W, Bi, Sb and Te. Average δ 34S values for galena and pyrite are -3.95 and -2.24‰, respectively, suggesting an igneous source for both the sulphur and metals. However, geological and geochemical interpretations suggest that at least some of the metals were leached from the metasandstones and diabases. Fluid inclusions in main-stage sphalerite homogenize at 229-384 °C with salinities ranging from 1.7 to 18.5 eq.wt% NaCl. The deposits formed as the result of the interaction of two aqueous fluids: a higher-salinity fluid (probably magmatic) and a dilute meteoric fluid. The narrow range of δ 34S (galena and pyrite) values (-5.2 to -1.2‰ CDT) suggests that the sulphur source of the hydrothermal fluids

  20. Pb-free Radiation Shielding Glass Using Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Watcharin Rachniyom

    2015-12-01

    Full Text Available In this work, Pb-free shielding glass samples were prepared by the melt quenching technique using subbituminous fly ash (SFA composed of xBi2O3 : (60-xB2O3 : 10Na2O : 30SFA (where x = 10, 15, 20, 25, 30 and 35 by wt%. The samples were investigated for their physical and radiation shielding properties. The density and hardness were measured. The results showed that the density increased with the increase of Bi2O3 content. The highest value of hardness was observed for glass sample with 30 wt% of Bi2O3 concentration. The samples were investigated under 662 keV gamma ray and the results were compared with theoretical calculations. The values of the mass attenuation coefficient (μm, the atomic cross section (σe and the effective atomic number (Zeff were found to increase with an increase of the Bi2O3 concentration and were in good agreement with the theoretical calculations. The best results for the half-value layer (HVL were observed in the sample with 35 wt% of Bi2O3 concentration, better than the values of barite concrete. These results demonstrate the viability of using coal fly ash waste for radiation shielding glass without PbO in the glass matrices.

  1. Bi-Force

    DEFF Research Database (Denmark)

    Sun, Peng; Speicher, Nora K; Röttger, Richard

    2014-01-01

    -clustering', has been successfully utilized to discover local patterns in gene expression data and similar biomedical data types. Here, we contribute a new heuristic: 'Bi-Force'. It is based on the weighted bicluster editing model, to perform biclustering on arbitrary sets of biological entities, given any kind...... of pairwise similarities. We first evaluated the power of Bi-Force to solve dedicated bicluster editing problems by comparing Bi-Force with two existing algorithms in the BiCluE software package. We then followed a biclustering evaluation protocol in a recent review paper from Eren et al. (2013) (A...... datasets from Gene Expression Omnibus were analyzed. All resulting biclusters were subsequently investigated by Gene Ontology enrichment analysis to evaluate their biological relevance. The distinct theoretical foundation of Bi-Force (bicluster editing) is more powerful than strict biclustering. We thus...

  2. Angle - resolved - photoemission study of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta. : Metallicity of the Bi-O plane

    Energy Technology Data Exchange (ETDEWEB)

    Wells, B.O.; Shen, Z.; Dessau, D.S.; Spicer, W.E.; Olson, C.G.; Mitzi, D.B.; Kapitulnik, A.; List, R.S.; Arko, A. (Stanford Electronics Laboratories, Stanford University, Stanford, CA (USA) Ames Laboratory, Iowa State University, Ames, IA Department of Applied Physics, Stanford University, Stanford, CA (USA) Los Alamos National Laboratory, Los Alamos, NM (USA))

    1990-12-10

    We have performed high-resolution angle-resolved-photoemission experiments on Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single crystals with different annealing histories. By depositing a small amount of Au on the surface, we were able to distinguish electronic states associated with the Bi-O surface layer. We found that the Bi-O atomic surface layer is metallic and superconducting for samples that were high-temperature annealed in oxygen but not for as-grown samples. The Cu-O plane is found to be superconducting in all samples.

  3. 冷却工艺对浸制备Bi-2223/Ag超导带临界电流密度的影响

    Institute of Scientific and Technical Information of China (English)

    汪京荣

    2004-01-01

    @@ 在Bi-Pb-Sr-Ca-Cu-O系统里,单一Bi-2223仅在空气中有银存在的830℃~845℃范围内是稳定的.对Bi-2223生长来说,Bi-2212是最理想的籽晶,因为有相同的组分和相似的结构.插入Ca-Cu-O,使Bi-2212转变成Bi-2223;Bi-2223变厚进入Bi-2212晶粒,使Bi-2212消融.Ca-Cu-O的插入是极慢的反应,控制着过程速率.

  4. Determination of Average Failure Time and Microstructural Analysis of Sn-Ag-Bi-In Solder Under Electromigration

    Science.gov (United States)

    Wu, Albert T.; Sun, K. H.

    2009-12-01

    Despite the extensive use of Sn-Ag-Cu as a Pb-free solder alloy, its melting point is significantly higher than that of eutectic Sn-Pb solder. Sn-Ag-Bi-In solder is an alternative Pb-free solder, with a melting temperature close to that of eutectic Sn-Pb. This study elucidates the electromigration behavior of Sn-Ag-Bi-In solder and then compares the results with those of the Sn-Ag-Bi system. The behavior of Pb-free Sn-Ag-Bi-In solder strips under electromigration is examined by preparing them in Si (001) U-grooves. The samples are then tested under various temperatures and current densities. Although the compounds thicken near both electrodes with current stressing, the thickness at the anode exceeds that at the cathode. Experimental results of the average failure time indicate that Sn-Ag-Bi-In solder has a longer lifetime than does Sn-Ag-Bi, which is attributed to the ζ phase. Additionally, the ζ phase dissolved by the current in the early stage replenishes the outgoing atomic flux. These atomic fluxes also enhance the growth of abnormally large particles in the middle of the strips. Field-emission electron probe microanalysis (FE-EPMA) results indicate that the amount of indium is reduced after the ζ phase near the cathode is exhausted for extended current stressing time.

  5. Preparation of granular Bi-2212 nanowires by electrospinning

    Science.gov (United States)

    Zeng, Xian Lin; Koblischka, Michael R.; Karwoth, Thomas; Hauet, Thomas; Hartmann, Uwe

    2017-03-01

    Bi2Sr2CaCu2O8 (Bi-2212) superconducting nanowires are synthesized by the electrospinning method. Two different precursors were employed to grow the nanowires, a Pb-doped one and a Cu,Ca-enriched one. The granular polycrystalline character was confirmed by scanning electron microscopy and x-ray diffraction measurement. The magnetic and electric properties of the samples were investigated via SQUID magnetometry and four-probe resistance measurements. The superconducting transition temperatures of the two systems were found to be similar (Pb-doped 84 K, Cu,Ca-enriched 76 K), but the transition width and the onset of irreversibility were clearly different. The magnetization loops and the resistance data demonstrate that the Cu,Ca-enriched precursor yields samples with better superconducting properties.

  6. Mechanism of visible light photocatalytic NO(x) oxidation with plasmonic Bi cocatalyst-enhanced (BiO)2CO3 hierarchical microspheres.

    Science.gov (United States)

    Sun, Yanjuan; Zhao, Zaiwang; Dong, Fan; Zhang, Wei

    2015-04-28

    Semimetal bismuth (Bi), as an emerging non-noble metal-based cocatalyst and plasmonic photocatalyst, has attracted significant attention. In this work, a one-pot solvent-controlled synthesis strategy was utilized for the in situ-deposition of plasmonic Bi nanoparticles onto the surfaces of (BiO)2CO3 microspheres (BOC-WE) using bismuth citrate, sodium carbonate, and ethylene glycol as precursors. The introduction of the Bi nanoparticles has a pivotal effect on the morphology, optical and photocatalytic performance of the pristine (BiO)2CO3. The results indicated that the Bi nanoparticles were generated on the surface of (BiO)2CO3 microspheres via the in situ reduction of Bi(3+) by ethylene glycol. The Bi-deposited (BiO)2CO3 microspheres were used for the photocatalytic purification of NOx in air under visible light irradiation. Significantly, the BOC-WE samples exhibited a drastically promoted photocatalytic performance with a NOx removal ratio (η) of 37.2%, superior to pristine (BiO)2CO3 (η = 19.1%), outperforming other well-known visible light photocatalysts, such as C-doped TiO2 (η = 21.8%), BiOBr (η = 21.3%), BiOI (η = 14.9%) and C3N4 (η = 25.5%). The conspicuously enhanced photocatalytic capability can be attributed to the synergistic effects of the surface plasmon resonance (SPR) effect, increased visible light absorption and the efficient separation of electron-hole pairs induced by the Bi nanoparticles. The Bi nanoparticles can act as a non-noble metal-based cocatalyst for strengthening photocatalytic performance, which is similar to the behavior of noble metals (Au, Ag) in enhancing photocatalysis. The mechanism of visible light photocatalytic NOx oxidation was investigated. DMPO-ESR spin-trapping results demonstrated that hydroxyl radicals were confirmed to be the main active species for NOx photo-oxidation. Due to the SPR effect of Bi, the BOC-WE could produce more hydroxyl radicals than BOC, which was responsible for the enhanced NO photo

  7. Optimization of Rolling Process for Bi(2223)/Ag Superconducting Tapes by a Statistical Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox tapes were prepared by the powder-in-tube method. The influences of rolling parameters on superconducting characteristics of Bi(2223)/Ag tapes were analyzed qualitatively with a statistical method. The results demonstrate that roll diameter and reduction per pass significantly influence the properties of superconducting tapes while roll speed does less and working friction the least. An optimized rolling process was therefore achieved according to the above results.

  8. Direct proton decay and microscopic structure of the spin-dipole resonance in Bi-208

    NARCIS (Netherlands)

    Akimune, H; Daito, [No Value; Fujita, Y; Fujiwara, M; Harakeh, MN; Janecke, J; Yosoi, M

    2000-01-01

    The microscopic structure of the spin-dipole resonance (SDR) at E-x = 21.1 MeV in Bi-208 has been investigated in the Pb-208(He-3,t)Bi-208 reaction at E(He-3) = 450 MeV and very forward scattering angles. Protons emitted due to the decay of the SDR were measured in solid-state detectors in coinciden

  9. Au pair trajectories

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    Since 2000, thousands of young Filipino migrants have come to Denmark as au pairs. Officially, they are there to “broaden their cultural horizons” by living temporarily with a Danish host family, but they also conduct domestic labor in exchange for food and money, which allows them to send import...... the Danish au pair scheme therefore speaks to current research on domestic work migration, the transnational family relations of young Filipina migrants and the forms of self-transformation that Filipino migration might engender.......Since 2000, thousands of young Filipino migrants have come to Denmark as au pairs. Officially, they are there to “broaden their cultural horizons” by living temporarily with a Danish host family, but they also conduct domestic labor in exchange for food and money, which allows them to send...... ethnographic component of the dissertation consists of four articles, all emphasizing the au pairs’ agency by viewing their migration as a dynamic personal and social experience. Arguing that Filipina au pairs tend to be understood primarily from the perspective of their precarious situation as domestic...

  10. New superconducting oxides in the Bi-Sr-Ca-Cu-0 system: magnetic measurements and structural determination

    Energy Technology Data Exchange (ETDEWEB)

    Giordanengo, B.; Godinho, M.; Lejay, P.; De Rango, P.; Sulpice, A.; Tholence, J.L.; Tournier, R. (Centre National de la Recherche Scientifique, 38 - Grenoble (FR) Centre de Recherches sur les Tres Basses Temperatures, Grenoble, (FR)); Hewat, A.W. (Institut Max Von Laue - Paul Langevin, 38 - Grenoble (FR)); Hewat, E.A. (CEA Centre d' Etudes Nucleaires de Grenoble 38 (FR). Inst. de Recherche Technologique et de Developpement Industriel (IRDI)); Marezio, M. (AT and T Bell Lab., Murray Hill, NJ (US)); Bordet, P.; Capponi, J.J.; Chaillout, C.; Chenavas, J.J.; Hodeau, J.L.; Spieser, A.M.; Tranqui, D. (Centre National de la Recherche Scientifique, 38 - Grenoble (FR) Lab. de Cristallographie (FR))

    1988-12-01

    Detailed neutron diffraction structure analysis of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} is reported. The effects of Pb-substitution on Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} and Bi{sub 2}Sr{sub 2}CuO{sub 6} are discussed, and magnetization measurement results on the 110 K phase in the Bi-Sr-Ca-Cu-O system are given.

  11. Wettability Studies of Pb-Free Soldering Materials

    Science.gov (United States)

    Moser, Z.; Gąsior, W.; Pstruś, J.; Dębski, A.

    2008-12-01

    For Pb-free soldering materials, two main substitutes are currently being considered, consisting of Sn-Ag and Sn-Ag-Cu eutectics, both with melting points higher than that of the Sn-Pb eutectic. Therefore, both will require higher soldering temperatures for industrial applications. Also, both eutectics have a higher surface tension than the Sn-Pb eutectic, requiring wettability studies on adding Bi, Sb, and In to the eutectics to decrease the melting points and surface tension. The experimental results for the surface tension were compared with thermodynamic modeling by Butler’s method and were used to create the SURDAT database, which also includes densities for pure metals, binary, ternary, quaternary, and quinary alloys. To model the surface tension, excess Gibbs energies of the molten components were taken from the ADAMIS database. For the case of the Ag-Sn system, enthalpies of formation of Ag3Sn from solution calorimetry were used for checking optimized thermodynamic parameters. In the study of Sn-Ag-Cu-Bi-Sb liquid alloys, the range of possible Bi compositions for practical applications has been used to formulate a generalized metric of wettability, which was checked by measurements of the influence of In on the Sn-Ag-Cu system.

  12. Experimental and Theoretical Study of the Feasibility of the Gunn Effect in BiSCl, BiSBr, BiSI, BiSeI, BiSeBr and BiSeCl.

    Science.gov (United States)

    1981-03-01

    BiSI has been measured with photon energy, from .2 ~e. to 3.6 eV. The band structures of BiSBr, BiSCI, BiSebr, BiSeCl and BiSel have 0.... been...ANDTIEORETICAL_,TUDY OF THE IASIBILITY OF TII-U EFFECT IN BI tlBiSBr, BISI, BiSel , WTSeBr ANWD BiSeCI* q ri1na Scientific Repot7- /t , .by J...measured with photon energy, lio, from 2.2 to 3.6 eV. The band structures of BiSBr, BiSCI, BiSI, BiSeBr, BiSeCI and BiSel have been calculated by using the

  13. Photoproduction of $J/\\psi$ in ultra-peripheral p-Pb and Pb-Pb collisions with the ALICE detector at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00360890

    The physics of ultra-peripheral collisions is introduced in the first part along with the fundamental concepts of several theoretical models. The measurement of photoproduction of vector mesons off proton and lead nucleus allows to study the QCD structure of these targets at energies that have never been measured before. The next parts of the text describe the measurements, the results, and present the physics discussion of the results. The aim of the thesis is to present the analysis of coherent $J/\\psi$ photoproduction in the forward rapidity in ultra-peripheral Pb-Pb collisions and the analysis of exclusive $J/\\psi$ photoproduction in ultra-peripheral p-Pb collisions in the forward, semi-forward and central rapidity. The personal contribution of the author in the Pb-Pb analysis consists in the determination of the efficiency of coherent, incoherent and two-photon processes and computations of the feed-down correction. In the case of the p-Pb analyses, the author has prepared and managed the official and au...

  14. 3D origami electrochemical device for sensitive Pb(2+) testing based on DNA functionalized iron-porphyrinic metal-organic framework.

    Science.gov (United States)

    Wang, Xiu; Yang, Chunlei; Zhu, Shaojun; Yan, Mei; Ge, Shenguang; Yu, Jinghua

    2017-01-15

    A highly sensitive electrochemical (EC) biosensor combined with a 3D origami device for detection of Pb(2+)was developed based on novel Au nanoparticles modified paper working electrode (Au-PWE) as sensor platform and DNA functionalized iron-porphyrinic metal-organic framework ((Fe-P)n-MOF-Au-GR) hybrids as signal probes. In the presence of Pb(2+), GR could be specifically cleaved at the ribonucleotide (rA) site, which produced the short (Fe-P)n-MOF-linked oligonucleotide fragment to hybridize with hairpin DNA immobilized on the surface of Au-PWE. Because of the mimic peroxidase property of (Fe-P)n-MOF, enzymatically amplified electrochemical signal was obtained to offer the sensitive detection of Pb(2+). In addition, benefiting from the Pb(2+) dependent GR, the proposed assay could selectively detect Pb(2+) in the presence of other metal ions. This method showed a good linear relationship between the current response and the Pb(2+) concentration ranging from 0.03 to 1000nmolL(-1) with a detection limit of 0.02nmolL(-1). The Au-PWE based electrochemical sensor along with the (Fe-P)n-MOF-Au-GR probe exhibited the advantages of low-cost, simple fabrication, high sensitivity and selectivity, providing potential application of real-time Pb(2+) detection both in environmental and biological samples.

  15. Measurement of 208Pb(n ,γ )209Pb Maxwellian averaged neutron capture cross section

    Science.gov (United States)

    Weissman, L.; Tessler, M.; Arenshtam, A.; Eliyahu, I.; Halfon, S.; Guerrero, C.; Kaizer, B.; Kijel, D.; Kreisel, A.; Palchan, T.; Paul, M.; Perry, A.; Schimel, G.; Silverman, I.; Shor, A.; Tamim, N.; Vaintraub, S.

    2017-07-01

    The doubly magic 208Pb nucleus is a bottleneck at the termination of the s -process path due to its very low neutron capture cross section. This cross section is also important for the decomposition of s , r processes and U/Th radiogenic decay contributions to the Pb-Bi solar abundances. The 208Pb(n ,γ )209Pb cross section was measured at the Soreq Applied Research Accelerator Facility Phase I using an intense quasi-Maxwellian neutron source produced by irradiation of the liquid-lithium target with a 1.5-mA continuous-wave proton beam at 1.94 MeV. The cross section was measured by counting the β activity from the irradiated lead target. The measurement allowed us to evaluate the Maxwellian averaged cross section (MACS) at 30 keV obtaining a value of 0.33(2) mb. This has been compared with the earlier activation and time-of-flight measurements found in the literature. The MACS cross-sectional value of the 63Cu(n ,γ )64Cu reaction was determined in the same experiment and is compared to a recent published value.

  16. Spin resonance transport properties of a single Au atom in S-Au-S junction and Au-Au-Au junction

    Science.gov (United States)

    Fangyuan, Wang; Guiqin, Li

    2016-07-01

    The spin transport properties of S-Au-S junction and Au-Au-Au junction between Au nanowires are investigated with density functional theory and the non-equilibrium Green's function. We mainly focus on the spin resonance transport properties of the center Au atom. The breaking of chemical bonds between anchor atoms and center Au atom significantly influences their spin transmission characteristics. We find the 0.8 eV orbital energy shift between anchor S atoms and the center Au atom can well protect the spin state stored in the S-Au-S junction and efficiently extract its spin state to the current by spin resonance mechanism, while the spin interaction of itinerant electrons and the valence electron of the center Au atom in the Au-Au-Au junction can extract the current spin information into the center Au atom. Fermi energy drift and bias-dependent spin filtering properties of the Au-Au-Au junction may transform information between distance, bias, and electron spin. Those unique properties make them potential candidates for a logical nanocircuit. Project supported by the National Basic Research Program of China (Grants No. 2011CB921602) and the National Natural Science Foundation of China (Grants No. 20121318158).

  17. Indicateurs cles au Canada

    OpenAIRE

    Warren, Paul

    2005-01-01

    Au cours des dernieres annees, on s'est beaucoup interesse sur la scene internationale aux indicateurs cles. Le present document se veut un tour d'horizon des efforts deployes recemment au Canada en vue d'elaborer des indicateurs cles du bien etre economique, social, environnemental et physique. Y sont classifies et examines en detail plus de 40 projets et publications portant sur ce sujet. Y figurent aussi l'enumeration breve de 20 autres projets, ainsi que des renvois a plusieurs enquetes a...

  18. Epitaxial integration of tetragonal BiFeO3 with silicon for nonvolatile memory applications

    Science.gov (United States)

    Zhu, Jingbin; Yin, Zhigang; Fu, Zhen; Zhao, Yajuan; Zhang, Xingwang; Liu, Xin; You, Jingbi; Li, Xingxing; Meng, Junhua; Liu, Heng; Wu, Jinliang

    2017-02-01

    Ferroelectric field-effect transistor has long been considered as a promising nonvolatile memory technology, but its application is limited by the poor scalability. Here we show that this problem can be solved by epitaxially integrating tetragonal BiFeO3, a stress-induced metastable phase which exhibits remarkably low dielectric permittivity and high coercive field, on the silicon platform. Tetragonal BiFeO3 was stabilized on (001)-oriented silicon by using Bi2SiO5, which is chemically and structurally compatible with both silicon and tetragonal BiFeO3, as the buffer layer. Unlike the commonly observed MC structure, the obtained BiFeO3 layer exhibits a true tetragonal symmetry. An unprecedented high memory window of 6.5 V was observed for the Au/BiFeO3/Bi2SiO5/Si capacitor with BiFeO3 thickness of 135 nm. The epitaxial integration of tetragonal BiFeO3 with silicon may pave a possible avenue for nanosized, power-efficient ferroelectric nonvolatile memories.

  19. Charmonium production in pp, pPb and PbPb with CMS

    CERN Document Server

    Lee, Songkyo

    2016-01-01

    We report on the analysis of charmonia in pp, pPb and PbPb collisions with the CMS experiment with various observables. The cross section for coherent J/$\\psi$ photoproduction is measured in ultra-peripheral PbPb collisions at 2.76 TeV. The ratio of yields at forward (proton-going direction) and backward (Pb-going direction) is studied as a function of $p_{\\rm T}$, rapidity, and the event activity in pPb collisions at 5.02 TeV. The nuclear modification factor of prompt J/$\\psi$ in PbPb collisions at 2.76 TeV is presented as a function of centrality, $p_{\\rm T}$, and rapidity. Finally, the production yields of $\\psi$(2S) and J/$\\psi$ in pp and PbPb collisions have been compared.

  20. Elliptic Flow of Charged Particles in Pb-Pb Collisions at sNN=2.76TeV

    Science.gov (United States)

    Aamodt, K.; Abelev, B.; Abrahantes Quintana, A.; Adamová, D.; Adare, A. M.; Aggarwal, M. M.; Aglieri Rinella, G.; Agocs, A. G.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad Masoodi, A.; Ahmad, N.; Ahn, S. U.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaráz Aviña, E.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldini Ferroli, R.; Baldisseri, A.; Baldit, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I. G.; Beck, H.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Bergmann, C.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biolcati, E.; Blanc, A.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Bombonati, C.; Book, J.; Borel, H.; Borissov, A.; Bortolin, C.; Bose, S.; Bossú, F.; Botje, M.; Böttger, S.; Boyer, B.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Breitner, T.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bugaiev, K.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, F.; Carena, W.; Carminati, F.; Casanova Díaz, A.; Caselle, M.; Castillo Castellanos, J.; Catanescu, V.; Cavicchioli, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chiavassa, E.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Coccetti, F.; Coffin, J.-P.; Coli, S.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Constantin, P.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Erasmo, G. D.; Dainese, A.; Dalsgaard, H. H.; Danu, A.; Das, D.; Das, I.; Das, K.; Dash, A.; Dash, S.; de, S.; de Azevedo Moregula, A.; de Barros, G. O. V.; de Caro, A.; de Cataldo, G.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; de Marco, N.; de Pasquale, S.; de Remigis, R.; de Rooij, R.; Debski, P. R.; Del Castillo Sanchez, E.; Delagrange, H.; Delgado Mercado, Y.; Dellacasa, G.; Deloff, A.; Demanov, V.; Dénes, E.; Deppman, A.; di Bari, D.; di Giglio, C.; di Liberto, S.; di Mauro, A.; di Nezza, P.; Dietel, T.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domínguez, I.; Dönigus, B.; Dordic, O.; Driga, O.; Dubey, A. K.; Dubuisson, J.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Dutta Majumdar, M. R.; Elia, D.; Emschermann, D.; Engel, H.; Erdal, H. A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evrard, S.; Eyyubova, G.; Fabjan, C. W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fearick, R.; Fedunov, A.; Fehlker, D.; Fekete, V.; Felea, D.; Feofilov, G.; Fernández Téllez, A.; Ferretti, A.; Ferretti, R.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Fini, R.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Fragkiadakis, M.; Frankenfeld, U.; Fuchs, U.; Furano, F.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Ganti, M. S.; Garabatos, C.; Garcia-Solis, E.; Garishvili, I.; Gemme, R.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Girard, M. R.; Giraudo, G.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; Ferreiro, E. G.; González Santos, H.; González-Trueba, L. H.; González-Zamora, P.; Gorbunov, S.; Gotovac, S.; Grabski, V.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerra Gutierrez, C.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Gutbrod, H.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Harris, J. W.; Hartig, M.; Hasch, D.; Hasegan, D.; Hatzifotiadou, D.; Hayrapetyan, A.; Heide, M.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Hernández, C.; Herrera Corral, G.; Herrmann, N.; Hetland, K. F.; Hicks, B.; Hille, P. T.; Hippolyte, B.; Horaguchi, T.; Hori, Y.; Hristov, P.; Hřivnáčová, I.; Huang, M.; Huber, S.; Humanic, T. J.; Hwang, D. S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G. M.; Innocenti, P. G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Jachołkowski, A.; Jacobs, P. M.; Jancurová, L.; Jangal, S.; Janik, R.; Jena, S.; Jirden, L.; Jones, G. T.; Jones, P. G.; Jovanović, P.; Jung, H.; Jung, W.; Jusko, A.; Kalcher, S.; Kaliňák, P.; Kalisky, M.; Kalliokoski, T.; Kalweit, A.; Kamermans, R.; Kanaki, K.; Kang, E.; Kang, J. H.; Kaplin, V.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Khan, M. M.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, D. J.; Kim, D. S.; Kim, D. W.; Kim, H. N.; Kim, J. H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, S. H.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kliemant, M.; Klovning, A.; Kluge, A.; Knichel, M. L.; Koch, K.; Köhler, M. K.; Kolevatov, R.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskih, A.; Kornaś, E.; Kottachchi Kankanamge Don, C.; Kour, R.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kozlov, K.; Kral, J.; Králik, I.; Kramer, F.; Kraus, I.; Krawutschke, T.; Kretz, M.; Krivda, M.; Krizek, F.; Krumbhorn, D.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucheriaev, Y.; Kuhn, C.; Kuijer, P. G.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kweon, M. J.; Kwon, Y.; La Rocca, P.; Ladrón de Guevara, P.; Lafage, V.; Lara, C.; Lardeux, A.; Larsen, D. T.; Lazzeroni, C.; Le Bornec, Y.; Lea, R.; Lee, K. S.; Lee, S. C.; Lefèvre, F.; Lehnert, J.; Leistam, L.; Lenhardt, M.; Lenti, V.; León Monzón, I.; León Vargas, H.; Lévai, P.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Liu, L.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Lohn, S.; Loizides, C.; Loo, K. K.; Lopez, X.; López Noriega, M.; López Torres, E.; Løvhøiden, G.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luparello, G.; Luquin, L.; Luzzi, C.; Ma, K.; Ma, R.; Madagodahettige-Don, D. M.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Mal'Kevich, D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Markert, C.; Martashvili, I.; Martinengo, P.; Martínez, M. I.; Martínez Davalos, A.; Martínez García, G.; Martynov, Y.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastromarco, M.; Mastroserio, A.; Matthews, Z. L.; Matyja, A.; Mayani, D.; Mayer, C.; Mazza, G.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Mendez Lorenzo, P.; Menis, I.; Mercado Pérez, J.; Meres, M.; Mereu, P.; Miake, Y.; Midori, J.; Milano, L.; Milosevic, J.; Mischke, A.; Miśkowiec, D.; Mitu, C.; Mlynarz, J.; Mohanty, A. K.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Monteno, M.; Montes, E.; Morando, M.; Moreira de Godoy, D. A.; Moretto, S.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Müller, H.; Munhoz, M. G.; Munoz, J.; Musa, L.; Musso, A.; Nandi, B. K.; Nania, R.; Nappi, E.; Nattrass, C.; Navach, F.; Navin, S.; Nayak, T. K.; Nazarenko, S.; Nazarov, G.; Nedosekin, A.; Nendaz, F.; Newby, J.; Nicassio, M.; Nielsen, B. S.; Niida, T.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Nilsson, M. S.; Noferini, F.; Nooren, G.; Novitzky, N.; Nyanin, A.; Nyatha, A.; Nygaard, C.; Nystrand, J.; Obayashi, H.; Ochirov, A.; Oeschler, H.; Oh, S. K.; Oleniacz, J.; Oppedisano, C.; Ortiz Velasquez, A.; Ortona, G.; Oskarsson, A.; Ostrowski, P.; Otterlund, I.; Otwinowski, J.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Jayarathna, S. P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S.; Pal, S. K.; Palaha, A.; Palmeri, A.; Pappalardo, G. S.; Park, W. J.; Patalakha, D. I.; Paticchio, V.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Peresunko, D.; Pérez Lara, C. E.; Perini, D.; Perrino, D.; Peryt, W.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A. J.; Petráček, V.; Petran, M.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Piano, S.; Piccotti, A.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piuz, F.; Piyarathna, D. B.; Platt, R.; Płoskoń, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polák, K.; Polichtchouk, B.; Pop, A.; Porteboeuf, S.; Pospíšil, V.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puddu, G.; Pulvirenti, A.; Punin, V.; Putiš, M.; Putschke, J.; Quercigh, E.; Qvigstad, H.; Rachevski, A.; Rademakers, A.; Rademakers, O.; Radomski, S.; Räihä, T. S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Ramírez Reyes, A.; Rammler, M.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Read, K. F.; Real, J.; Redlich, K.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R. A.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rodríguez Cahuantzi, M.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Rosinský, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Rivetti, A.; Rusanov, I.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Sahu, P. K.; Saini, J.; Saiz, P.; Sakai, S.; Sakata, D.; Salgado, C. A.; Samanta, T.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Šándor, L.; Sandoval, A.; Sano, M.; Sano, S.; Santo, R.; Santoro, R.; Sarkamo, J.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schreiner, S.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P. A.; Scott, R.; Segato, G.; Selyuzhenkov, I.; Senyukov, S.; Seo, J.; Serci, S.; Serradilla, E.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharma, N.; Sharma, S.; Shigaki, K.; Shimomura, M.; Shtejer, K.; Sibiriak, Y.; Siciliano, M.; Sicking, E.; Siemiarczuk, T.; Silenzi, A.; Silvermyr, D.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.; Søgaard, C.; Soloviev, A.; Soltz, R.; Son, H.; Song, J.; Song, M.; Soos, C.; Soramel, F.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Stefanini, G.; Steinbeck, T.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stocco, D.; Stock, R.; Stokkevag, C. H.; Stolpovskiy, M.; Strmen, P.; Suaide, A. A. P.; Subieta Vásquez, M. A.; Sugitate, T.; Suire, C.; Sukhorukov, M.; Šumbera, M.; Susa, T.; Swoboda, D.; Symons, T. J. M.; Szanto de Toledo, A.; Szarka, I.; Szostak, A.; Tagridis, C.; Takahashi, J.; Tapia Takaki, J. D.; Tauro, A.; Tavlet, M.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Thäder, J.; Thomas, D.; Thomas, J. H.; Tieulent, R.; Timmins, A. R.; Tlusty, D.; Toia, A.; Torii, H.; Toscano, L.; Tosello, F.; Traczyk, T.; Truesdale, D.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Turvey, A. J.; Tveter, T. S.; Ulery, J.; Ullaland, K.; Uras, A.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Vacchi, A.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; van der Kolk, N.; van Leeuwen, M.; Vande Vyvre, P.; Vannucci, L.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernekohl, D. C.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopyanov, A.; Voloshin, K.; Voloshin, S.; Volpe, G.; von Haller, B.; Vranic, D.; Øvrebekk, G.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, V.; Wan, R.; Wang, D.; Wang, Y.; Wang, Y.; Watanabe, K.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, A.; Wilk, G.; Williams, M. C. S.; Windelband, B.; Xaplanteris Karampatsos, L.; Yang, H.; Yang, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yu, W.; Yuan, X.; Yushmanov, I.; Zabrodin, E.; Zach, C.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zelnicek, P.; Zenin, A.; Zgura, I.; Zhalov, M.; Zhang, X.; Zhou, D.; Zichichi, A.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.

    2010-12-01

    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sNN=2.76TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2Au-Au collisions at sNN=200GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

  1. Second step in the field-cooled magnetization of Bi-2212 single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Koblischka, M.R.; Murakami, M. [International Superconductivity Technology Center (ISTEC), Tokyo (Japan). Superconductivity Research Lab.

    2000-03-01

    In all Bi-based superconductors [Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi-2212), (Pb,Bi){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+{delta}}] the critical current density, j{sub c}, is found to increase steeply when decreasing the temperature below {approx}25 K (see, e.g.). In the case of Bi-2223 tapes, the pinning-dominated intragranular current density is found to increase considerably, whereas the transport current density shows only a small increase. Furthermore, determinations of the irreversibility line (IL) showed that there are two different regimes, a high field one with the irreversibility field H{sub irr}{proportional_to}exp(-T/T{sub 0}), and a low field regime. (orig.)

  2. Crystal structure and electronic properties of a thiolate-protected Au24 nanocluster

    Science.gov (United States)

    Das, Anindita; Li, Tao; Li, Gao; Nobusada, Katsuyuki; Zeng, Chenjie; Rosi, Nathaniel L.; Jin, Rongchao

    2014-05-01

    Solving the total structures of gold nanoclusters is of critical importance for understanding their electronic, optical and catalytic properties. Herein, we report the X-ray structure of a charge-neutral Au24(SCH2Ph-tBu)20 nanocluster. This structure features a bi-tetrahedral Au8 kernel protected by four tetrameric staple-like motifs. Electronic structure analysis is further carried out and the optical absorption spectrum is interpreted. The Au24(SCH2Ph-tBu)20, Au23(S-c-C6H11)16 and Au25(SCH2CH2Ph)18 nanoclusters constitute the first crystallographically characterized ``trio''.Solving the total structures of gold nanoclusters is of critical importance for understanding their electronic, optical and catalytic properties. Herein, we report the X-ray structure of a charge-neutral Au24(SCH2Ph-tBu)20 nanocluster. This structure features a bi-tetrahedral Au8 kernel protected by four tetrameric staple-like motifs. Electronic structure analysis is further carried out and the optical absorption spectrum is interpreted. The Au24(SCH2Ph-tBu)20, Au23(S-c-C6H11)16 and Au25(SCH2CH2Ph)18 nanoclusters constitute the first crystallographically characterized ``trio''. Electronic supplementary information (ESI) available: Experimental and supporting Fig. S1-S3. CCDC NUMBER(1000102). For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4nr01350f

  3. Catalytic activity of Au nanoparticles

    DEFF Research Database (Denmark)

    Larsen, Britt Hvolbæk; Janssens, Ton V.W.; Clausen, Bjerne

    2007-01-01

    Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change with par......Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change...... with particle size. We find that the fraction of low-coordinated Au atoms scales approximately with the catalytic activity, suggesting that atoms on the corners and edges of Au nanoparticles are the active sites. This effect is explained using density functional calculations....

  4. Garnet composite films with Au particles fabricated by repetitive formation for enhancement of Faraday effect

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, H; Nakai, Y [Department of Electronics and Intelligent Systems, Tohoku Institute of Technology, 35-1 Yagiyama-Kasumi, Taihaku, Sendai, Miyagi 982-8577 (Japan); Mizutani, Y; Inoue, M [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Fedyanin, A A, E-mail: uchida_hn@tohtech.ac.jp [Faculty of Physics, Moscow State University, Moscow 119992 (Russian Federation)

    2011-02-16

    To prepare garnet (Bi : YIG) composite films with Au particles, we used a repetitive formation method to increase the number density of particles. On increasing the number of repetitions, the diameter distribution of the particles changed. After five repetitions using 5 nm Au films, the diameter distribution separated into two size groups. Shift of wavelength-excited localized surface plasmon resonance is discussed relative to the diameter distribution. In the composite films, enhancement of Faraday rotation associated with surface plasmons was observed. With six repetitions, a maximum enhanced rotation of -1.2{sup 0} was obtained, which is 20 times larger than that of a single Bi : YIG film. The figures of merit for the composite films are discussed. The thickness of a Bi : YIG composite film working for enhanced Faraday rotation was examined using an ion milling method.

  5. A Portable and Power-Free Microfluidic Device for Rapid and Sensitive Lead (Pb2+) Detection

    OpenAIRE

    Lianhui Wang; Shiping Song; Gang Liu; Shijiang He; Chunhui Fan

    2012-01-01

    A portable and power-free microfluidic device was designed for rapid and sensitive detection of lead (Pb2+). 11-mercaptoundecanoic acid (MUA)-functionalized gold nanoparticles (MUA-AuNPs) aggregated in the presence of Pb2+ for the chelation mechanism. When we performed this analysis on a polydimethylsiloxane (PDMS) microfluidic chip, the aggregations deposited onto the surface of chip and formed dark lines along the laminar flows in the zigzag micr...

  6. Magnetic susceptibilities of liquid Cr-Au, Mn-Au and Fe-Au alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, S.; Shimakura, H. [Niigata University of Pharmacy and Applied Life Sciences, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Tahara, S. [Faculty of Science, University of the Ryukyus, Nishihara-cho, Okinawa 903-0213 (Japan); Okada, T. [Niigata College of Technology, Kamishin’eicho, Nishi-ku, Niigata 950-2076 (Japan)

    2015-08-17

    The magnetic susceptibility of liquid Cr-Au, Mn-Au, Fe-Au and Cu-Au alloys was investigated as a function of temperature and composition. Liquid Cr{sub 1-c}Au{sub c} with 0.5 ≤ c and Mn{sub 1-c}Au{sub c} with 0.3≤c obeyed the Curie-Weiss law with regard to their dependence of χ on temperature. The magnetic susceptibilities of liquid Fe-Au alloys also exhibited Curie-Weiss behavior with a reasonable value for the effective number of Bohr magneton. On the Au-rich side, the composition dependence of χ for liquid TM-Au (TM=Cr, Mn, Fe) alloys increased rapidly with increasing TM content, respectively. Additionally, the composition dependences of χ for liquid Cr-Au, Mn-Au, and Fe-Au alloys had maxima at compositions of 50 at% Cr, 70 at% Mn, and 85 at% Fe, respectively. We compared the composition dependences of χ{sub 3d} due to 3d electrons for liquid binary TM-M (M=Au, Al, Si, Sb), and investigated the relationship between χ{sub 3d} and E{sub F} in liquid binary TM-M alloys at a composition of 50 at% TM.

  7. Heating rate effect on the evolution of texture in (Bi,Pb)2Sr2Ca2Cu3O10 Ag-sheathed tapes

    DEFF Research Database (Denmark)

    Grivel, J.C.; Raittila, J.; Xu, G.J.

    2005-01-01

    Bi2223/Ag tapes have been produced by the powder-in-tube technique. The evolution of texture during the first heat treatment has been studied by means of in situ synchrotron radiation diffraction. Using various heating rates (1, 2 and 4 degrees C min(-1)), it wag found that the kinetics of prefer......Bi2223/Ag tapes have been produced by the powder-in-tube technique. The evolution of texture during the first heat treatment has been studied by means of in situ synchrotron radiation diffraction. Using various heating rates (1, 2 and 4 degrees C min(-1)), it wag found that the kinetics...

  8. Chlorine adlayer-templated growth of a hybrid inorganic-organic layered structure on Au(111)

    Science.gov (United States)

    Rzeźnicka, I. I.; Horino, H.; Yagyu, K.; Suzuki, T.; Kajimoto, S.; Fukumura, H.

    2016-10-01

    Growth of a hybrid inorganic-organic layered structure on the Au(111) surface using a one-step solution growth is reported. The hybrid structure is consist of 4,4‧-bipyridine [4,4‧-BiPyH2]2 + cations, Cl anions and Au adatoms, provided from substrate by means of the adsorbate-induced surface phase transition of a surface reconstruction. Its surface and bulk structures were characterized by scanning tunneling microscopy (STM), secondary ion mass spectrometry (SIMS), and Raman spectroscopy. STM results reveal growth of the first [4,4‧-BiPyH2]2 + layer on top of the p(√{ 3} ×√{ 3})" separators=", R 30 ° chlorine overlayer formed on the Au(111) surface. These two layers are found to provide a platform for a following three-dimensional growth facilitated by hydrogen bonding, aurophilic and π-π stacking interactions.

  9. XAFS study of rhombohedral ferroelectric PbHf{sub 0.9}Ti{sub 0.1}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Sicron, N.; Yacoby, Yizhak [Hebrew Univ., Racah Inst. of Physics, Jerusalem (Israel)

    1999-11-01

    The local structure of the rhombohedral perovskite PbHf{sub 0.9}Ti{sub 0.1}O{sub 3} was studied using Pb and Hf XAFS. XAFS data were analyzed by fitting a parameterized theoretical spectrum to the experimental data using the four nearest coordination shells. It was found that the Ti off center displacement is different from that of Hf. Furthermore, the Pb-O and Pb-Pb, bonds have very large Debye Waller factors indicating that Pb and possibly O atoms are disordered about the rhombohedral positions down to 11K. Despite the structural disorder, the local structure of PbHf{sub 0.9}Ti{sub 0.1}O{sub 3} is closer to the rhombohedral average structure measured by diffraction than to the structure of pure PbHfO{sub 3} or PbTiO{sub 3}. (au) 10 refs.

  10. Solid-Phase Equilibria in the Au-As, Au-Ga-Sb, Au-In-As, and Au-In-Sb Ternaries.

    Science.gov (United States)

    1986-02-28

    AD6i5 469 SOLID- PHASE EQUILIBRIA IN THE Ru-As AU-GA-SB AU-IN-AS- 1/17 AND AU-IN-SB TERNAR (U) CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY AND...REPORT & PERIOD COVERED SOLID- PHASE EQUILIBRIA IN THE Au-Ga-As, Au-Ga-Sb Thchnical Report Au-In-As, and Au-In-Sb TEARIEIS S. PERFORMING ORG. REPORT NUMBER...CLASSIFICATION OF THIS PAGEMI*n Does Entepd) 4./ lie- . .- - - - - -- -- Solid Phase Equilibria in the Au-Ga-As, Au-Ga-Sb, Au-In-As, and Au-In-Sb Ternaries C

  11. Measurements of $D_{S}^{\\pm}$-meson production in Au+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV in STAR

    CERN Document Server

    ,

    2016-01-01

    We present the first measurement of the nuclear modification factor $R_{AA}$ and elliptic flow $v_{2}$ of $D_{s}$ in Au+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV with the STAR detector. These results have been compared with those of other open charm mesons and strange mesons to determine how the (possibly) strangeness equilibrated partonic matter affects the $D_{s}$ meson production. We find that the nuclear modification factor of $D_{S}$ are systematically higher than unity and $D^{0}$ $R_{\\rm{AA}}$. The ratio $D_{s}/D^{0}$ is shown as a function of transverse momentum for the 10-40$\\%$ most central Au+Au collisions and compared with that in $p+p$ collisions obtained from PYTHIA. It is also compared with that in Pb-Pb collisions at 2.76 TeV by the ALICE experiment. Our measurement indicates a hint of enhancement of $D_{S}$ production in Au+Au collisions with respect to $p+p$ collisions as compared to non-strange $D$ mesons.

  12. Fluorescent detection of lead in environmental water and urine samples using enzyme mimics of catechin-synthesized Au nanoparticles.

    Science.gov (United States)

    Wu, Yan-Shiuan; Huang, Fan-Feng; Lin, Yang-Wei

    2013-02-01

    A facile, cost-effective, and sensitive fluorescent method for Pb²⁺ ion detection had been developed using catechin synthesized gold nanoparticles (C-Au NPs). The Pb-catechin complexes and Pb-Au alloys that formed on the C-Au NPs surfaces allowed NPs to exhibit peroxidase-mimicking catalytic activity in the H₂O₂-mediated oxidation of Amplex UltraRed (AUR). In 5 mM Tris-acetate buffers at pH 7.0, the H₂O₂-AUR-C-Au NP probe was highly selective (>100-fold) for Pb²⁺ ions in the presence of other tested metal ions (K⁺, Ag⁺, Na⁺, Cd²⁺, Ni²⁺, Ca²⁺, Hg²⁺, Sr²⁺, Co²⁺, Cu²⁺, Ba²⁺, Fe²⁺, Mg²⁺, Cr³⁺, and Fe³⁺ ions). The fluorescence intensity (excitation/emission maxima ∼540/588 nm) of the AUR product was proportional to the concentration of Pb²⁺ ions in the range of 10 nM-1.0 μM with a linear correlation (R² = 0.99). The H₂O₂-AUR-C-Au NP probe detected Pb²⁺ ions with a limit of detection (signal-to-noise ratio: 3) of 1.5 nM. The practicality of the H₂O₂-AUR-C-Au NP probe was validated for the determination of Pb²⁺ ion concentration in environmental water and urine samples, demonstrating its advantages of simplicity, selectivity, and sensitivity.

  13. Alpha-Decay of $^{211}Po$ on the 1633 keV $^{207}Pb$ level

    CERN Document Server

    Chumin, V G; Malikov, Sh R; Norseev, Yu V; Samatov, Z K; Fominykh, V I; Cherevatenko, A P; Yurkova, L V

    2000-01-01

    In investigations of gamma-spectrum of ^{211}At and daughter ^{211}Po and ^{207}Bi isotopes a new branch of the alpha-decay on the ^{207}Pb 1633 keV level is discovered. Its intensity is 8.1 cdot 10^{-4} %.

  14. Spin Hall effect in 5d Au: W transition metal alloys (Conference Presentation)

    Science.gov (United States)

    Laczkowski, Piotr; Rojas-Sánchez, Juan Carlos; Savero-Torres, Williams; Reyren, Nicolas; Deranlot, Cyrile; George, Jean-Marie; Jaffrès, Henri; Fu, Yu; Marty, Alain; Warin, Patrick; Attané, Jean-Philippe; Vila, Laurent; Fert, Albert

    2016-10-01

    The spin Hall effect (SHE) [1] allows for a reciprocal conversion between charge and spin currents using the spin orbit coupling which can be at the core of several promising spintronics devices. The spin orbit interaction is used to produce a transverse flow of spin or charge in response to a longitudinal excitation, these are the direct or inverse SHE. The spin Hall angle (SHA), the ratio of longitudinal and transverse electronic conductivities, is the characterising parameter of this conversion. So far, large SHA have been reported in transition metals like Pt, Pd, W, Beta-Ta and in a few alloys with large spin orbit coupling impurities: CuIr, CuBi or CuPb [2]. In this presentation we will report on our study of the SHA in Au based alloys [3] which exhibits a non-monotonic relation with the impurity concentration. In the regime of diluted alloys this behaviour suggests the dominent side-jump contribution to the spin Hall resistivity, thus allowing precise tuning of the SHA as a function of impurities concentration. We will present our analyses results by using the Lateral Spin Valves, with newly introduced spin-absorption model adapted to the case of the strong spin-orbit interactions and by using complementary Ferromagnetic-Resonance/Spin-Pumping technique thus demonstrating very large SHA of the order of 15 % or even larger. [1] J.E. Hirsch, PRL 83, 1834 (1999). [2] Y. Niimi et al., PRL 106, 126601 (2011), PRL 109, 156602 (2012), PRB 89, 054401 (2014). [3] P. Laczkowski et al., APL 104, 142403 (2014) [4] E. Saitoh, et al., APL 88, 182509 (2006).

  15. /Au Back Contacts

    Science.gov (United States)

    Paudel, Naba R.; Compaan, Alvin D.; Yan, Yanfa

    2014-08-01

    We report on the fabrication and characterization of CdTe thin-film solar cells with Cu-free MoO3- x /Au back contacts. CdTe solar cells with sputtered CdTe absorbers of thicknesses from 0.5 to 1.75 μm were fabricated on Pilkington SnO2:F/SnO2-coated soda-lime glasses coated with a 60- to 80-nm sputtered CdS layer. The MoO3- x /Au back contact layers were deposited by thermal evaporation. The incorporation of MoO3- x layer was found to improve the open circuit voltage ( V OC) but reduce the fill factor of the ultrathin CdTe cells. The V OC was found to increase as the CdTe thickness increased.

  16. Cerenkov counting: an alternative for determining {sup 210} Pb low-levels

    Energy Technology Data Exchange (ETDEWEB)

    Mingote, Raquel Maia; Gomes, Nilton Carlos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Servico de Quimica e Radioquimica]. E-mail: mingote@cdtn.br; Oliveira, Arno Heeren de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear]. E-mail: heeren@nuclear.ufmg.br

    2005-07-01

    Determining the {sup 210}Pb by Cerenkov counting is an indirect method which is measured by the Cerenkov radiation produced by its daughter {sup 210}Bi. {sup 210}Pb does not interfere because it does not produce Cerenkov radiation and only the lead chemical recovery is necessary, decreasing the uncertainty sources. This work presents a methodology for determining {sup 210}Pb in water for Cerenkov counting by using a conventional sp