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Sample records for deficient sn isotopes

  1. Study of neutron-deficient Sn isotopes

    International Nuclear Information System (INIS)

    Auger, G.

    1982-05-01

    The formation of neutron deficient nuclei by heavy ion reactions is investigated. The experimental technique is presented, and the results obtained concerning Sn et In isotopes reported: first excited states of 106 Sn, high spin states in 107 Sn and 107 In; Yrast levels of 106 Sn, 107 Sn, 108 Sn; study of neutron deficient Sn and In isotopes formed by the desintegration of the compound nucleus 112 Xe. All these results are discussed [fr

  2. Laser spectroscopy of neutron deficient Sn isotopes

    CERN Multimedia

    We propose to study the ground state properties of neutron-deficient Sn isotopes towards the doubly-magic nucleus $^{100}$Sn. Nuclear spins, changes in the rms charge radii and electromagnetic moments of $^{101-121}$Sn will be measured by laser spectroscopy using the CRIS experimental beam line. These ground-state properties will help to clarify the evolution of nuclear structure properties approaching the $\\textit{N = Z =}$ 50 shell closures. The Sn isotopic chain is currently the frontier for the application of state-of-the-art ab-initio calculations. Our knowledge of the nuclear structure of the Sn isotopes will set a benchmark for the advances of many-body methods, and will provide an important test for modern descriptions of the nuclear force.

  3. Coulomb Excitation of Neutron Deficient Sn-Isotopes using REX-ISOLDE

    CERN Multimedia

    Di julio, D D; Kownacki, J M; Marechal, F; Andreoiu, C; Siem, S; Perrot, F; Van duppen, P L E; Napiorkowski, P J; Iwanicki, J S

    2002-01-01

    It is proposed to study the evolution of the reduced transition probabilities, B(E2; 0$^{+} \\rightarrow$ 2$^{+}$), for neutron deficient Sn isotopes by Coulomb excitation in inverse kinematics using REX-ISOLDE and the MINIBALL detector array. Measurements of the reduced transition matrix element for the transition between the ground state and the first excited 2$^{+}$ state in light even-even Sn isotopes provide a means to study e.g. core polarization effects in the $^{100}$Sn core. Previous attempts to measure this quantity have been carried out using the decay of isomeric states populated in fusion evaporation reactions. We thus propose to utilize the unique opportunity provided by REX-ISOLDE, after the energy upgrade to 3.1 MeV/u, to use the more model-independent approach of Coulomb excitation to measure this quantity in a number of isotopes in this region.

  4. Towards 100Sn: Studies on neutron-deficient even isotopes of tin

    International Nuclear Information System (INIS)

    Rathke, G.E.

    1987-02-01

    Neutron-deficient 108,106,104 Sn isotopes were produced by heavy ion induced fusion reactions using high-intensity 59 Ni beams from the UNILAC of the GSI. Their decay properties were studied by techniques of gamma and conversion electron spectroscopy employing the mass separator on-line to the UNILAC. Earlier information on the 108 Sn → 108 In and 106 Sn → 106 In decays was complemented and improved in the course of this work. The new nucleus 104 Sn and its decay to excited states in 104 In was identified and studied for the first time. These investigations yield the following results: the mass of 104 Sn and of nuclei linked to it by alpha decay or proton radioactivity, 108 Te, 112 Xe and 109 I, 113 Cs, respectively were determined from the measured Q EC value of 104 Sn and the known mass value of 104 In. These are nuclei very close or beyond the proton drip line. In addition, information on the quenching of the fast Gamow-Teller beta decay of the even neutron-deficient tin isotopes was obtained. This complements investigations on the N = 50 isotones 94 Ru and 96 Pd, and allows a systematic comparison of these transition strengths for nuclei near the doubly magic 100 Sn. The spreading of the vertical strokeπg 9/2 -1 vg 7/2 , 1 + > configuration over several states, due to residual interactions, and the centroid energies of these magnetic dipole states were determined for the corresponding odd-odd indium isotopes. (orig./HSI)

  5. Further studies of neutron-deficient Sn-isotopes using REX-ISOLDE

    CERN Multimedia

    Larsen, A; Syed naeemul, H; Siem, S

    2007-01-01

    Encouraged by the committee to submit the latter part of our latest addendum to experiment IS418 under a new heading this proposal focuses on the second physics case mentioned there. We propose to use Coulomb excitation of odd mass neutron-deficient Sn isotopes to study some dominantly "one quasi-particle" states in these nuclei. Due to spin selection rules these states are difficult to populate following either $\\beta$-decay or in a cascade after a fusion-evaporation reactions, whereas the excitation from the ground-state is of E2 character for some of the most interesting cases.

  6. Generalized-seniority scheme in light Sn isotopes

    International Nuclear Information System (INIS)

    Sandulescu, N.; Blomqvist, J.; Liotta, R.J.; Engeland, T.; Hjorth-Jensen, M.; Holt, A.; Osnes, E.

    1998-01-01

    In the last years the region of light Sn isotopes has been intensively investigated both from experimental and theoretical perspectives. The main goal was to study the excitation mechanisms around the exotic isotope 100 Sn, the heaviest symmetric double magic nucleus which may exist. The simplest approach in analysing the spectra of light tin isotopes is to consider 100 Sn as an inert core and to treat only neutron degrees of freedom in the valence shell N = 50-82. Extensive shell model calculations have been performed on this line. On the other hand, a large part of the light Sn isotopes spectra could be rather well described in terms of simple quasiparticle excitations. Therefore one expects that at least a part of the low-lying states in this region are well approximated in shell-model subspaces with reduced dimensions. An alternative in truncating the shell model space to low-dimensions is the generalized seniority scheme (GSEN). The aim of this letter is to analyse the accuracy of the GSEN scheme for the case of light tin isotopes. In the present calculations we use a microscopically derived interaction. The yrast generalized seniority states are compared with the corresponding shell model states for the case of the tin isotopes 104-112 Sn. For most of the states that agreement is within 100 keV, although the SM space is drastically truncated. For instance, in 110 Sn the number of SM basis states 2 + is 86990, compared with 9 in the case of GSEN. The seniority two states correspond to the particle-number projected QRPA (Quasiparticle Random Phase Approximation) states. One expects the quasiparticle approximations to break down when the number of active nucleons is small. In order to investigate this in the case of light Sn isotopes, we calculated also the energies predicted by QRPA. The agreement of the QRPA with the exact SM result is impressive, even in the case of only few extra-core neutrons. This is due to the large pairing correlations in the high

  7. Coulomb excitation of $^{110}$Sn using REX-ISOLDE

    CERN Document Server

    Ekström, A; Hurst, A; Fahlander, C; Banu, A; Butler, P; Eberth, J; Górska, M; Habs, D; Huyse, M; Kester, O; Niedermayer, O; Nilsson, T; Pantea, M; Scheit, H; Schwalm, D; Sletten, G; Ushasi, D P; Van Duppen, P; Warr, N; Weisshaar, D

    2006-01-01

    In this paper, we report the preliminary result from the first Coulomb excitation experiment at REX-ISOLDE (Habs et al 1998 Nucl. Instrum. Methods B 139 128) using neutron-deficient Sn-beams. The motivation of the experiment is to deduce the reduced transition probability, B(E2 ; 2$^+\\rightarrow$ 0$^+$) , for the sequence of neutron deficient, unstable, even-even Sn-isotopes from using a radioactive beam opens up a new path to study the lifetime of the first excited 2$^+$ state in these isotopes. The de-excitation path following fusion-evaporation reactions will for the even-even Sn isotopes pass via an isomeric 6$^+$ state, located at higher energy, which thus hampers measurements of the lifetime of the first excited state using, e.g., recoil-distance methods. For this reason the reduced transition probability of the first excited 2$^+$ state has remained unknown in this chain of isotopes although the B(E2) value of the stable isotope $^{112}$Sn was measured approximately 30 years ago (see, e.g., Stelson et...

  8. Realistic shell-model calculations for Sn isotopes

    International Nuclear Information System (INIS)

    Covello, A.; Andreozzi, F.; Coraggio, L.; Gargano, A.; Porrino, A.

    1997-01-01

    We report on a shell-model study of the Sn isotopes in which a realistic effective interaction derived from the Paris free nucleon-nucleon potential is employed. The calculations are performed within the framework of the seniority scheme by making use of the chain-calculation method. This provides practically exact solutions while cutting down the amount of computational work required by a standard seniority-truncated calculation. The behavior of the energy of several low-lying states in the isotopes with A ranging from 122 to 130 is presented and compared with the experimental one. (orig.)

  9. Decay properties of nuclei in the neighbourhood of {sup 100}Sn; Zerfallseigenschaften von Nukliden in der Umgebung von {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Straub, Katrin

    2011-01-24

    This thesis concentrates on nuclear properties of very neutron deficient nuclei near the proton dripline in the neighbourhood of doubly-magic {sup 100}Sn. In an experiment performed in March 2008 at the GSI in Darmstadt, the exotic nuclei were produced in a projectile fragmentation reaction using a {sup 124}Xe primary beam with an energy of 100 AMeV impinging on a 4000 Beryllium target, separated and identified in the FRS and eventually stopped for decay spectroscopy in a complex implantation detector developed at the institute E12. The Germanium array RISING was employed for the measurement of prompt and delayed gamma radiation. Production cross sections and half lives were determined along the proton dripline. The isotopes {sup 99}Sn, {sup 97}In and {sup 95}Cd were identified for the first time. additional nuclei studied in this thesis are {sup 103}Sn, {sup 96}Cd as well as the two tin isotopes {sup 101}Sn and {sup 102}Sn. (orig.)

  10. Coulomb excitation of {sup 107}Sn

    Energy Technology Data Exchange (ETDEWEB)

    DiJulio, D.D.; Cederkall, J.; Fahlander, C. [Lund University, Physics Department, 118, Lund (Sweden); Ekstroem, A. [University of Oslo, Department of Physics and Center of Mathematics for Applications, Oslo (Norway); Hjorth-Jensen, M. [University of Oslo, Department of Physics and Center of Mathematics for Applications, Oslo (Norway); Michigan State University, National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, East Lansing, MI (United States); Albers, M.; Blazhev, A.; Fransen, C.; Geibel, K.; Hess, H.; Reiter, P.; Seidlitz, M.; Taprogge, J.; Warr, N. [University of Cologne, Institute of Nuclear Physics, Cologne (Germany); Bildstein, V.; Gernhaeuser, R.; Wimmer, K. [Technische Universitaet Muenchen, Physik Department E12, Garching (Germany); Darby, I.; Witte, H. de [Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Davinson, T. [University of Edinburgh, Department of Physics and Astronomy, Edinburgh (United Kingdom); Diriken, J. [Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Studiecentrum voor Kernenergie/Centre d' Etude de l' energie Nucleaire (SCK CEN), Mol (Belgium); Goergen, A.; Siem, S.; Tveten, G.M. [University of Oslo, Department of Physics, Oslo (Norway); Iwanicki, J. [University of Warsaw, Heavy Ion Laboratory, Warsaw (Poland); Lutter, R. [Ludwig-Maximilians-Universitaet Muenchen, Fakultaet fuer Physik, Garching (Germany); Scheck, M. [University of Liverpool, Oliver Lodge Laboratory, Liverpool (United Kingdom); Walle, J.V. de [PH Department, Geneva 23 (Switzerland); Voulot, D.; Wenander, F. [AB Department, Geneva 23 (Switzerland)

    2012-07-15

    The radioactive isotope {sup 107}Sn was studied using Coulomb excitation at the REX-ISOLDE facility at CERN. This is the lightest odd-Sn nucleus examined using this technique. The reduced transition probability of the lowest-lying 3/2{sup +} state was measured and is compared to shell-model predictions based on several sets of single-neutron energies relative to {sup 100}Sn. Similar to the transition probabilities for the 2{sup +} states in the neutron-deficient even-even Sn nuclei, the measured value is underestimated by shell-model calculations. Part of the strength may be recovered by considering the ordering of the d{sub 5/2} and g{sub 7/2} single-neutron states. (orig.)

  11. NMR Isotope Tracking Reveals Cascade Steps in Carbohydrate Conversion by Sn-Beta

    DEFF Research Database (Denmark)

    Elliot, Samuel Gilbert; Taarning, Esben; Madsen, Robert

    2017-01-01

    Quantitative isotope tracking studies were used to investigate the reaction pathways occurring for Sn-Beta catalyzed carbohydrate conversion to various alpha-hydroxy esters. Experimental insight into the conversion of pentoses was sought (i) by identifying pathways based on isotope patterns in th...

  12. Decay properties of nuclei in the neighbourhood of 100Sn

    International Nuclear Information System (INIS)

    Straub, Katrin

    2011-01-01

    This thesis concentrates on nuclear properties of very neutron deficient nuclei near the proton dripline in the neighbourhood of doubly-magic 100 Sn. In an experiment performed in March 2008 at the GSI in Darmstadt, the exotic nuclei were produced in a projectile fragmentation reaction using a 124 Xe primary beam with an energy of 100 AMeV impinging on a 4000 Beryllium target, separated and identified in the FRS and eventually stopped for decay spectroscopy in a complex implantation detector developed at the institute E12. The Germanium array RISING was employed for the measurement of prompt and delayed gamma radiation. Production cross sections and half lives were determined along the proton dripline. The isotopes 99 Sn, 97 In and 95 Cd were identified for the first time. additional nuclei studied in this thesis are 103 Sn, 96 Cd as well as the two tin isotopes 101 Sn and 102 Sn. (orig.)

  13. Coulomb excitation of neutron-rich $^{134-136}$Sn isotopes

    CERN Multimedia

    We propose to study excited states in the isotopes $^{134,136}$Sn by $\\gamma$-ray spectroscopy following "safe" Coulomb excitation. The experiment aims to investigate the evolution of quadrupole collectivity beyond the magic shell closure at N = 82 by the determination of B(E2) values and electric quadrupole moments $\\mathcal{Q}_2$. Recent shell-model calculations using realistic interactions predict possible enhanced collectivity in neutron-rich regions. Evidence for this could be obtained by this experiment. Furthermore, the currently unknown excitation energies of the 2$^+_{1}$ and 4$^+_{1}$ states in $^{136}$Sn will be measured for the first time.

  14. Isotope correlations as a probe for freeze-out characterization: central {sup 124}Sn+{sup 64}Ni, {sup 112}Sn+{sup 58}Ni collisions

    Energy Technology Data Exchange (ETDEWEB)

    Geraci, E.; Alderighi, M.; Anzalone, A.; Auditore, L.; Baran, V.; Bartolucci, M.; Berceanu, I.; Blicharska, J.; Bonasera, A.; Borderie, B.; Bougault, R.; Bruno, M.; Brzychczyk, J.; Cardella, G.; Cavallaro, S.; Chbihi, A.; Cibor, J.; Colonna, M.; D' Agostino, M.; De Filippo, E.; Di Toro, M.; Giustolisi, F.; Grzeszczuk, A.; Guazzoni, P.; Guinet, D.; Iacono-Manno, M.; Kowalski, S.; La Guidara, E.; Lanzalone, G.; Lanzano, G.; Le Neindre, N.; Li, S.; Lo Nigro, S.; Maiolino, C.; Majka, Z.; Manfredi, G.; Paduszynski, T.; Pagano, A.; Papa, M.; Petrovici, M.; Piasecki, E.; Pirrone, S.; Politi, G.; Pop, A.; Porto, F.; Rivet, M.F.; Rosato, E.; Russo, S.; Russotto, P.; Sechi, G.; Simion, V.; Sperduto, M.L.; Steckmeyer, J.C.; Trifiro, A.; Trimarchi, M.; Vannini, G.; Vigilante, M.; Wieleczko, J.P.; Wilczynski, J.; Wu, H.; Xiao, Z.; Zetta, L.; Zipper, W

    2004-04-05

    {sup 124}Sn+{sup 64}Ni and {sup 112}Sn+{sup 58}Ni reactions at 35 AMeV incident energy were studied with the forward part of CHIMERA multi-detector. The most central collisions were selected by means of a multidimensional analysis. The characteristics of the source formed in the central collisions, as size, temperature and volume, were inspected. The measured isotopes of light fragments (3 {<=} Z {<=} 8) were used to examine isotope yield ratios that provide information on the free neutron to proton densities.

  15. Study of Neutron-Deficient $^{202-205}$Fr Isotopes with Collinear Resonance Ionization Spectroscopy

    CERN Document Server

    De Schepper, Stijn; Cocolios, Thomas; Budincevic, Ivan

    The scope of this master’s thesis is the study of neutron-deficient $^{202−205}$Fr isotopes. These isotopes are inside the neutron-deficient lead region, a region that has shown evidence of shape coexistence. For this thesis, this discussion is limited to the phenomenon where a low lying excited state has a different shape than the ground state. Shape coexistence is caused by intruder states. These are single-particle Shell Model states that are perturbed in energy due to the interaction with a deformed core. In the neutron-deficient lead region the main proton intruder orbit is the 3s$_{1/2}$orbit. When going towards more neutron-deficient isotopes, deformation increases. The $\\pi3s_{1/2}$orbit will rise in energy and will eventually become the ground state in odd- A bismuth (Z=83) isotopes. It is also observed in odd-A astatine (Z=85) isotopes, already in less neutron-deficient nuclei. The same phenomenon is expected to be present francium (Z=87) isotopes already at $^{199}$Fr. Although it is currently ...

  16. No evidence of reduced collectivity in Coulomb-excited Sn isotopes

    Science.gov (United States)

    Kumar, R.; Saxena, M.; Doornenbal, P.; Jhingan, A.; Banerjee, A.; Bhowmik, R. K.; Dutt, S.; Garg, R.; Joshi, C.; Mishra, V.; Napiorkowski, P. J.; Prajapati, S.; Söderström, P.-A.; Kumar, N.; Wollersheim, H.-J.

    2017-11-01

    In a series of Coulomb excitation experiments the first excited 2+ states in semimagic Sn 112 ,116 ,118 ,120 ,122 ,124 isotopes were excited using a 58Ni beam at safe Coulomb energy. The B (E 2 ; 0+→2+) values were determined with high precision (˜3 %) relative to 58Ni projectile excitation. These results disagree with previously reported B (E 2 ↑) values [A. Jungclaus et al., Phys. Lett. B 695, 110 (2011)., 10.1016/j.physletb.2010.11.012] extracted from Doppler-shift attenuation lifetime measurements, whereas the reported mass dependence of B (E 2 ↑) values is very similar to a recent Coulomb excitation study [J. M. Allmond et al., Phys. Rev. C 92, 041303(R) (2015), 10.1103/PhysRevC.92.041303]. The stable Sn isotopes, key nuclei in nuclear structure, show no evidence of reduced collectivity and we, thus, reconfirm the nonsymmetric behavior of reduced transition probabilities with respect to the midshell A =116 .

  17. Radiochemical studies of neutron deficient actinide isotopes

    International Nuclear Information System (INIS)

    Williams, K.E.

    1978-04-01

    The production of neutron deficient actinide isotopes in heavy ion reactions was studied using alpha, gamma, x-ray, and spontaneous fission detection systems. A new isotope of berkelium, 242 Bk, was produced with a cross-section of approximately 10 μb in reactions of boron on uranium and nitrogen on thorium. It decays by electron capture with a half-life of 7.0 +- 1.3 minutes. The alpha-branching ratio for this isotope is less than 1% and the spontaneous fission ratio is less than 0.03%. Studies of (Heavy Ion, pxn) and (Heavy Ion, αxn) transfer reactions in comparison with (Heavy ion, xn) compound nucleus reactions revealed transfer reaction cross-sections equal to or greater than the compound nucleus yields. The data show that in some cases the yield of an isotope produced via a (H.I.,pxn) or (H.I.,αxn) reaction may be higher than its production via an xn compound nucleus reaction. These results have dire consequences for proponents of the ''Z 1 + Z 2 = Z/sub 1+2/'' philosophy. It is no longer acceptable to assume that (H.I.,pxn) and (H.I.,αxn) product yields are of no consequence when studying compound nucleus reactions. No evidence for spontaneous fission decay of 228 Pu, 230 Pu, 232 Cm, or 238 Cf was observed indicating that strictly empirical extrapolations of spontaneous fission half-life data is inadequate for predictions of half-lives for unknown neutron deficient actinide isotopes

  18. Isotopic Dependence of the Giant Monopole Resonance in the Even-A 112-124Sn Isotopes and the Asymmetry Term in Nuclear Incompressibility

    International Nuclear Information System (INIS)

    Li, T.; Garg, U.; Liu, Y.; Marks, R.; Nayak, B. K.; Rao, P. V. Madhusudhana; Fujiwara, M.; Hashimoto, H.; Kawase, K.; Nakanishi, K.; Okumura, S.; Yosoi, M.; Itoh, M.; Ichikawa, M.; Matsuo, R.; Terazono, T.; Uchida, M.; Kawabata, T.; Akimune, H.; Iwao, Y.

    2007-01-01

    The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112-124) with inelastic scattering of 400-MeV α particles in the angular range 0 deg. - 8.5 deg. We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in 208 Pb and 90 Zr very well. From the GMR data, a value of K τ =-550±100 MeV is obtained for the asymmetry term in the nuclear incompressibility

  19. Isotopic Dependence of the Giant Monopole Resonance in the Even-A Sn112 124 Isotopes and the Asymmetry Term in Nuclear Incompressibility

    Science.gov (United States)

    Li, T.; Garg, U.; Liu, Y.; Marks, R.; Nayak, B. K.; Rao, P. V. Madhusudhana; Fujiwara, M.; Hashimoto, H.; Kawase, K.; Nakanishi, K.; Okumura, S.; Yosoi, M.; Itoh, M.; Ichikawa, M.; Matsuo, R.; Terazono, T.; Uchida, M.; Kawabata, T.; Akimune, H.; Iwao, Y.; Murakami, T.; Sakaguchi, H.; Terashima, S.; Yasuda, Y.; Zenihiro, J.; Harakeh, M. N.

    2007-10-01

    The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112 124) with inelastic scattering of 400-MeV α particles in the angular range 0° 8.5°. We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in Pb208 and Zr90 very well. From the GMR data, a value of Kτ=-550±100MeV is obtained for the asymmetry term in the nuclear incompressibility.

  20. Radiochemical studies of neutron deficient actinide isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Williams, K.E.

    1978-04-01

    The production of neutron deficient actinide isotopes in heavy ion reactions was studied using alpha, gamma, x-ray, and spontaneous fission detection systems. A new isotope of berkelium, /sup 242/Bk, was produced with a cross-section of approximately 10 ..mu..b in reactions of boron on uranium and nitrogen on thorium. It decays by electron capture with a half-life of 7.0 +- 1.3 minutes. The alpha-branching ratio for this isotope is less than 1% and the spontaneous fission ratio is less than 0.03%. Studies of (Heavy Ion, pxn) and (Heavy Ion, ..cap alpha..xn) transfer reactions in comparison with (Heavy ion, xn) compound nucleus reactions revealed transfer reaction cross-sections equal to or greater than the compound nucleus yields. The data show that in some cases the yield of an isotope produced via a (H.I.,pxn) or (H.I.,..cap alpha..xn) reaction may be higher than its production via an xn compound nucleus reaction. These results have dire consequences for proponents of the ''Z/sub 1/ + Z/sub 2/ = Z/sub 1+2/'' philosophy. It is no longer acceptable to assume that (H.I.,pxn) and (H.I.,..cap alpha..xn) product yields are of no consequence when studying compound nucleus reactions. No evidence for spontaneous fission decay of /sup 228/Pu, /sup 230/Pu, /sup 232/Cm, or /sup 238/Cf was observed indicating that strictly empirical extrapolations of spontaneous fission half-life data is inadequate for predictions of half-lives for unknown neutron deficient actinide isotopes.

  1. Description of the Gamov-Teller β+-decay of tin isotopes

    International Nuclear Information System (INIS)

    Kuz'min, V.A.; Solov'ev, V.G.

    1988-01-01

    The integrated log(ft) values of Gamow-Teller β + decays of the neutron-deficient tine isotopes are calculated in the random phase approximation with particle-hole and particle-particle residual interactions which parameters have been fixed earlier. For |g A /g V |=1 and |g A /g V |=1.263 a good correspondence with the experimental data is obtained for 104,106,108 Sn and a prediction is made for 102 Sn. It is shown that one cannot define from the rate of neutron-deficient nuclei β + decay the renormalization of the axial-vector weak interaction constant g A

  2. Charge radii of neutron-deficient Ca isotopes

    Science.gov (United States)

    Miller, A. J.; Minamisono, K.; Klose, A.; Everett, N.; Kalman, C.; Powel, R. C.; Watkins, J.; Garand, D.; Sumithrarachchi, C.; Krämer, J.; Maa, B.; Nörtershäuser, W.; Rossi, D. M.; Kujawa, C.; Pineda, S.; Lantis, J.; Liu, Y.; Mantica, P. F.; Pearson, M. R.

    2017-09-01

    Nucleon shell closures are generally associated with a local minimum in mean-square charge radii, 〈r2 〉 , along an isotopic chain. The 〈r2 〉 of 18Ar and 19K isotopes, however, do not show this signature at the N = 20 neutron shell closure. To gain a microscopic understanding of this abnormal behavior, measurements of 〈r2 〉 of neutron-deficient Ca isotopes below N = 20 have been proposed at the BEam COoling and LAser spectroscopy (BECOLA) facility at NSCL/MSU. Preliminary results will be presented and the deduced charge radii will be compared to theoretical calculations and the trends in the nearby isotopic chains. Work supported in part by NSF Grant PHY-15-65546, U.S. DOE Grant DE-NA0002924 and by the Deutsche Forschungsgemeinschaft through Grant SFB 1245.

  3. Moessbauer spectroscopy of isotope separator implanted sup(119m)Sn in FCC metals

    International Nuclear Information System (INIS)

    Larsen, A.N.; Weyer, G.

    1979-01-01

    Radioactive sup(119m)Sn has been implanted in FCC metals by means of an isotope separator. Moessbauer spectra have been measured for the 24 keV transition of 119 Sn. Large substitutional fractions are found in all cases. A correlation for substitutional lattice sites between the measured isomer shifts of the impurity atoms and the force constants of the host lattices is discussed. Debye-Waller factors determined for substitutional Sn in the host lattices are found to be smaller than values calculated by a simple mass-defect model. For some host metals indications of an influence of radiation damage on the spectra are observed. Defect sites are assigned to Sn in aluminium and lead. Qualitative conclusions on the structures of these defects are drawn from the determined Moessbauer parameters. (author)

  4. The two-proton shell gap in Sn isotopes

    International Nuclear Information System (INIS)

    Fleischer, P.; Kluepfel, P.; Reinhard, P.-G.; Cornelius, T.; Schramm, S.; Maruhn, J.A.; Buervenich, T.J.

    2004-01-01

    We present an analysis of two-proton shell gaps in Sn isotopes. As theoretical tool we use self-consistent mean-field models, namely the relativistic mean-field model and the Skyrme-Hartree-Fock approach, both with two different pairing forces, a delta interaction (DI) model and a density-dependent delta interaction (DDDI). We investigate the influence of nuclear deformation as well as collective correlations and find that both effects contribute significantly. Moreover, we find a further significant dependence on the pairing force used. The inclusion of deformation plus correlation effects and the use of DDDI pairing provides agreement with the data. (orig.)

  5. Skin Dose Equivalent Measurement from Neutron-Deficient Isotopes

    International Nuclear Information System (INIS)

    Hsu, Hsiao-Hua; Costigan, Steve A.; Romero, Leonard L.; Whicker, Jeffrey J.

    1997-12-01

    Neutron-deficient-isotopes decay via positron emission and/or electron capture often followed by x-ray, gamma-ray, and 0.511 MeV photons from positron annihilation. For cases of significant area and/or personnel contamination with these isotopes, determination of skin dose equivalent (SDE) is required by 10CFR835. For assessment of SDE, we evaluated the MICROSPEC-2(TM) system manufactured by Bubble Technology Industries of Canada which uses three different probes for dose measurement. We used two probes: (1) the X-probe which measures lower energy (4 - 120 keV) photon energy distributions and determines deep dose equivalent, SDE and dose equivalent to eyes, and (2) the B-probe which measures electron (positron) energy distributions, and determines skin dose equivalent. Also, the measured photon and beta spectra can be used to identify radioactive isotopes in the contaminated area. Measurements with several neutron-deficient sources showed that this system provided reasonably accurate SDE rate measurements when compared with calculated benchmark SDE rates with an average percent difference of 40%. Variations were expected because of differences between the assumed geometries used by MlCROSPEC-2 and the calculations when compared to the measurement conditions

  6. New neutron-deficient isotopes of barium and rare-earth elements

    CERN Document Server

    Bogdanov, D D; Karnaukhov, V A; Petrov, L A; Plochocki, A; Subbotin, V G; Voboril, J

    1976-01-01

    The authors present an investigation of the short-lived neutron- deficient isotopes of barium and rare-earth elements. By using the BEMS-2 isotope separator on a heavy ion beam, 19 new isotopes were produced with mass numbers ranging from 117 to 138. Five of these (/sup 117/Ba, /sup 129,131/Nd and /sup 133,135/Sm) turned out to be delayed proton emitters. The beta -decay probabilities for the new isotopes have been analyzed in terms of the beta -strength function. An analysis of the proton spectrum shape has been performed using the statistical model for delayed proton emission.

  7. Tin isotope fractionation during magmatic processes and the isotope composition of the bulk silicate Earth

    Science.gov (United States)

    Wang, Xueying; Amet, Quentin; Fitoussi, Caroline; Bourdon, Bernard

    2018-05-01

    Tin is a moderately volatile element whose isotope composition can be used to investigate Earth and planet differentiation and the early history of the Solar System. Although the Sn stable isotope composition of several geological and archaeological samples has been reported, there is currently scarce information about the effect of igneous processes on Sn isotopes. In this study, high-precision Sn isotope measurements of peridotites and basalts were obtained by MC-ICP-MS with a double-spike technique. The basalt samples display small variations in δ124/116Sn ranging from -0.01 ± 0.11 to 0.27 ± 0.11‰ (2 s.d.) relative to NIST SRM 3161a standard solution, while peridotites have more dispersed and more negative δ124Sn values ranging from -1.04 ± 0.11 to -0.07 ± 0.11‰ (2 s.d.). Overall, basalts are enriched in heavy Sn isotopes relative to peridotites. In addition, δ124Sn in peridotites become more negative with increasing degrees of melt depletion. These results can be explained by different partitioning behavior of Sn4+ and Sn2+ during partial melting. Sn4+ is overall more incompatible than Sn2+ during partial melting, resulting in Sn4+-rich silicate melt and Sn2+-rich residue. As Sn4+ has been shown experimentally to be enriched in heavy isotopes relative to Sn2+, the effect of melting is to enrich residual peridotites in relatively more compatible Sn2+, which results in isotopically lighter peridotites and isotopically heavier mantle-derived melts. This picture can be disturbed partly by the effect of refertilization. Similarly, the presence of enriched components such as recycled oceanic crust or sediments could explain part of the variations in Sn isotopes in oceanic basalts. The most primitive peridotite analyzed in this study was used for estimating the Sn isotope composition of the BSE, with δ124Sn = -0.08 ± 0.11‰ (2 s.d.) relative to the Sn NIST SRM 3161a standard solution. Altogether, this suggests that Sn isotopes may be a powerful probe of

  8. Study of asymmetric fission yield behavior from neutron-deficient Hg isotope

    International Nuclear Information System (INIS)

    Perkasa, Y. S.; Waris, A.; Kurniadi, R.; Su'ud, Z.

    2014-01-01

    A study of asymmetric fission yield behavior from a neutron-deficient Hg isotope has been conducted. The fission yield calculation of the neutron-deficient Hg isotope using Brownian Metropolis shape had showed unusual result at decreasing energy. In this paper, this interesting feature will be validated by using nine degree of scission shapes parameterization from Brosa model that had been implemented in TALYS nuclear reaction code. This validation is intended to show agreement between both model and the experiment result. The expected result from these models considered to be different due to dynamical properties that implemented in both models

  9. Laser spectroscopy of neutron deficient gold and platinum isotopes

    International Nuclear Information System (INIS)

    Savard, G.

    1988-03-01

    A new method for on-line laser spectroscopy of radioactive atoms based on the resonant ionization spectroscopy of laser-desorbed radioactive samples has been devised. An experimental setup has been installed on-line at the ISOCELE mass separator in Orsay (France) and experiments have been performed on the region of transitional nuclei around Z=79. Isotopic shift measurements on four new isotopes 194 Au, 196 Au, 198 Au, 199 Au have been performed on gold and results on the neutron deficient isotopes down to 186 Au have been obtained confirming the nuclear ground-state shape transition from oblate to prolate between 187 Au and 186 Au. The first isotopic shift measurements on radioactive platinum isotopes have been obtained on 186 Pt, 188 Pt, 189 Pt. Indications of a shape transition have been observed between 186 Pt and 188 Pt. The extracted experimental changes in mean square charge radii δ 2 > A,A' along isotopic chains are compared to self-consistent Hartree-Fock plus BCS calculations

  10. Spectroscopy of very neutron-deficient hafnium and tungsten isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Dracoulis, G D; Fabricius, B; Davidson, P M [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics; Macchiavelli, A O; Oliviera, J; Burde, J; Stephens, F; Deleplanque, M A [Lawrence Berkeley Lab., CA (United States)

    1992-08-01

    Level schemes of the very neutron-deficient isotopes {sup 158}Hf and {sup 162}W have been identified, and that for {sup 164}W extended. Alignment of the H{sub 9/2} neutrons is suggested. (author). 12 refs., 7 figs.

  11. Shell structure in the vicinity of the doubly magic {sup 100}Sn via Coulomb excitation at PreSPEC

    Energy Technology Data Exchange (ETDEWEB)

    Guastalla, Giulia

    2014-11-17

    The PreSPEC setup in combination with the high intensity primary beams available at GSI provided unique opportunities for the key nuclear structure studies on exotic nuclei. The experiment performed on the neutron deficient {sup 104}Sn aimed to deduce the reduced transition probability of the first excited 2{sup +} state quantified by the B(E2; 0{sup +} → 2{sup +}) value. This result is the central point in the discussion of the evolution of nuclear structure in proximity of the doubly magic nucleus {sup 100}Sn. As {sup 100}Sn is not yet accessible for such measurements, a series of experiments have been performed for neutron-deficient Sn isotopes over the past few years. These data showed excessive experimental B(E2) strength compared to shell model calculations below neutron number N=64 and they are therefore not excluding a constant or even increasing collectivity below {sup 106}Sn. Hence, the measurement of the B(E2) value in the next even-even isotope toward {sup 100}Sn, i.e. {sup 104}Sn, was a crucial step to verify the robustness of the shell gap of {sup 100}Sn. Moreover, {sup 104}Sn is the heaviest isotope of the Sn isotopic chain for which a shell model calculation without significant truncation of the valence space can be performed and therefore with this experimental value the validity of Large Scale Shell Model (LSSM) calculations could be tested. As a main result of the experiment a B(E2) value corresponding to 0.10(4) e{sup 2}b{sup 2} has been extracted for {sup 104}Sn. The experimental value showed a very good agreement with the predicted one and, despite the large error bar, it clearly established a downward trend of the B(E2) values of the Sn isotopic chain toward A=100. This implied enhanced stability of the N = Z = 50 shell closure against ph-excited quadrupole modes. However, an experiment of this kind is very challenging for several reasons. First, {sup 104}Sn lies in proximity of the proton drip line and has therefore a small production

  12. Shape coexistence in the neutron-deficient Pt isotopes in the configuration-mixed IBM

    International Nuclear Information System (INIS)

    Vargas, Carlos E.; Campuzano, Cuauhtemoc; Morales, Irving O.; Frank, Alejandro; Van Isacker, Piet

    2008-01-01

    The matrix-coherent state approach in the IBM with configuration mixing is used to describe the geometry of neutron-deficient Pt isotopes. Employing a parameter set for all isotopes determined previously, it is found that the lowest minimum goes from spherical to oblate and finally acquires a prolate shape when approaching the mid-shell Pt isotopes

  13. Collinear Resonance Ionization Spectroscopy of Neutron-Deficient Francium Isotopes

    CERN Document Server

    Flanagan, K T; Ruiz, R F Garcia; Budincevic, I; Procter, T J; Fedosseev, V N; Lynch, K M; Cocolios, T E; Marsh, B A; Neyens, G; Strashnov, I; Stroke, H H; Rossel, R E; Heylen, H; Billowes, J; Rothe, S; Bissell, M L; Wendt, K D A; de Groote, R P; De Schepper, S

    2013-01-01

    The magnetic moments and isotope shifts of the neutron-deficient francium isotopes Fr202-205 were measured at ISOLDE-CERN with use of collinear resonance ionization spectroscopy. A production-to-detection efficiency of 1\\% was measured for Fr-202. The background from nonresonant and collisional ionization was maintained below one ion in 10(5) beam particles. Through a comparison of the measured charge radii with predictions from the spherical droplet model, it is concluded that the ground-state wave function remains spherical down to Fr-205, with a departure observed in Fr-203 (N = 116).

  14. Monopole Effect on Isotopes in Sn and Pb Regions

    Directory of Open Access Journals (Sweden)

    M. KHITER

    2016-11-01

    Full Text Available Abstract. When going toward in description of neutron-rich nuclei, the monopole field plays a determining role in the properties of the quasiparticle states and their interactions. Detailed theoretical in shell model calculations of the characteristics of the neutron-rich isotopes in 132Sn and 208Pb regions are performed using the monopole hamiltonien effect. Some modification mentioned in literatures of effectives interactions are introduced for evaluated the effective single-particle energies. Their effect show a successful and consistent description of excitation energies spectra of these nuclei.Keywords:Nuclear Structure, Monopole Hamiltonian, Odd-Odd Nuclei,Three body Effects, Similarity, 21.60.Cs; 27.60. +j; 21.30.Fe

  15. Shape coexistence in the neutron-deficient Pt isotopes in a configuration mixing IBM

    International Nuclear Information System (INIS)

    Morales, Irving O.; Vargas, Carlos E.; Frank, Alejandro

    2004-01-01

    The recently proposed matrix-coherent state approach for configuration mixing IBM is used to describe the evolving geometry of the neutron deficient Pt isotopes. It is found that the Potential Energy Surface (PES) of the Platinum isotopes evolves, when the number of neutrons decreases, from spherical to oblate and then to prolate shapes, in agreement with experimental measurements. Oblate-Prolate shape coexistence is observed in 194,192Pt isotopes

  16. Deformation and mixing of co-existing shapes in the neutron-deficient polonium isotopes

    CERN Document Server

    AUTHOR|(CDS)2078559; Huyse, Mark

    The neutron-deficient polonium isotopes, with only 2 protons outside the Z = 82 shell closure, are situated in an interesting region of the nuclear chart. In the neighboring lead (Z = 82) and mercury (Z = 80) isotopes, experimental and theoretical efforts identified evidence of shape coexistence. Shape coexistence is the remarkable phenomenon in which two or more distinct types of deformation occur in states of the same angular momentum and similar excitation energy in a nucleus. The neutron-deficient polonium isotopes have also been studied intensively, experimentally as well as theoretically. The closed neutron-shell nucleus 210Po (N = 126) manifests itself as a two-particle nucleus where most of the excited states can be explained by considering the degrees of freedom of the two valence protons outside of 208Pb. The near-constant behavior of the yrast 2+1 and 4+1 states in the isotopes with mass 200 ≤ A ≤ 208 can be explained by coupling the two valence protons to a vibrating lead core. 200Po seems to ...

  17. Centrifugal extraction of highly enriched tin isotopes and increase of specific activity of the radionuclide 119mSn on the gas centrifuge cascade

    International Nuclear Information System (INIS)

    Suvorov, I.A.; Tcheltsov, A.N.; Sosnin, L.Yu.; Sazikin, A.A.; Rudnev, A.I.

    2002-01-01

    This work contains the results of research on centrifugal enrichment of 118 Sn isotope followed by irradiation and, finally, a second centrifugal enrichment to produce high specific activity 119m Sn. Non-steady-state separation methods were used for the effective extraction of the radionuclide 119m Sn from the irradiated target. As a result of this work, radiation sources based on 119m Sn were obtained with a specific activity of 500 mCi/g. This is 100 times greater than the specific activity obtained after irradiation in the reactor alone. In addition, the sources had an previously unattainable radio-purity ratio of 113 Sn/ 119m Sn of approximately 10 -6

  18. Catalytic recombination of dissociation products with Pt/SnO2 for rare and common isotope long-life, closed-cycle CO2 lasers

    Science.gov (United States)

    Brown, Kenneth G.; Sidney, B. D.; Schryer, D. R.; Upchurch, B. T.; Miller, I. M.

    1986-01-01

    This paper reports results on recombination of pulsed CO2 laser dissociation products with Pt/SnO2 catalysts, and supporting studies in a surrogate laboratory catalyst reactor. The closed-cycle, pulsed CO2 laser has been continuously operated for one million pulses with an overall power degradation of less than 5 percent by flowing the laser gas mixture through a 2-percent Pt/SnO2 catalyst bed. In the surrogate laboratory reactor, experiments have been conducted to determine isotopic exchange with the catalyst when using rare-isotope gases. The effects of catalyst pretreatment, sample weight, composition, and temperature on catalyst efficiency have also been determined.

  19. The effect of the pairing interaction on the energies of isobar analogue resonances in {sup 112-124}Sb and isospin admixture in {sup 100-124}Sn isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Babacan, Tahsin [Department of Physics, Celal Bayar University, Manisa (Turkey); Salamov, Djavad [Department of Physics, Anadolu University, Eskisehir (Turkey); Kuecuekbursa, Atalay [Department of Physics, Dumlupinar University, Kuetahya (Turkey); Babacan, Halil [Department of Physics, Celal Bayar University, Manisa (Turkey); Maras, Ismail [Department of Physics, Celal Bayar University, Manisa (Turkey); Aygoer, Hasan A [Department of Physics, Celal Bayar University, Manisa (Turkey); Uenal, Arslan [Department of Physics, Dumlupinar University, Kuetahya (Turkey)

    2004-06-01

    In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analogue resonances (IAR) in {sup 112-124}Sb isotopes and the isospin admixture in {sup 100-124}Sn isotopes is investigated within the framework of the proton-neutron quasi-particle random phase approximation (pnQRPA). The form of the interaction strength parameter is related to the shell-model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the {sup 100-124}Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral J{sub F} for the Sn({sup 3}He,t)Sb reactions at E({sup 3}He) =200 MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the {sup 100}Sn isotope is in good agreement with Colo et al's estimates (4-5%), and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al (53 {+-} 5 MeV fm{sup 3}). Moreover, it is concluded that although the differential cross section of the isobar analogue resonance for the ({sup 3}He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in N {approx} Z isotopes can be seen with the presence of these correlations.

  20. Total β-decay energies and masses of tin, antimony and tellurium isotopes in the vicinity of 50132Sn82

    International Nuclear Information System (INIS)

    Lund, E.; Aleklett, K.; Rudstam, G.

    1977-01-01

    Experimental β-decay energies for short-lived isotopes of tin, antimony and tellurium are presented. Mass-separated sources were produced at the on-line isotope separator OSIRIS. By applying β-γ coincidence methods, total β-decay energies have been determined for the following nuclides: 127-131 Sn, 128 130 131 134 Sb and 134 135 Te. The atomic mass excess has been derived for these nuclei, and comparisons are made with mass formula predictions. (Auth.)

  1. Laser spectroscopy of cadmium isotopes: probing the nuclear structure between the neutron 50 and 82 shell closures

    CERN Multimedia

    Blaum, K; Stroke, H H; Krieger, A R

    We propose to study the isotopic chain of cadmium with high-resolution laser spectroscopy for the first time. Our goal is to determine nuclear spins, moments and root-mean-square charge radii of ground and isomeric states between the neutron 50 and 82 shell closures, contributing decisively to a better understanding of the nuclear structure in the vicinity of the doubly-magic $^{100}$Sn and $^{132}$Sn. On the neutron-rich side this is expected to shed light on a shell-quenching hypothesis and consequently on the duration of the r-process along the waiting-point nuclei below $^{130}$Cd. On the neutron-deficient side it may elucidate the role of the cadmium isotopes in the rp-process for rapidly accreting neutron stars.

  2. Isotope techniques in studies of selenium deficiency and toxicity syndromes in farm animals

    International Nuclear Information System (INIS)

    Giese, W.W.

    1984-01-01

    In a brief review of the Se deficiency syndrome in ruminants, studies using non-isotopic methods are applied to an introductory description of the disease. They include methods currently applied for determining Se deficiency status in feed and in ruminant animals. Detection of potential white muscle disease in lambs and calves is discussed. The application of 75 Se in studies on absorption, tissue distribution and excretion under feeding regimes with different Se levels and partly with addition of SO 4 ions or vitamin E is reviewed. In vitro studies with 75 Se include a description of the 75 Se uptake test with red blood cells, the metabolism of selenite, selenate and selenomethionine in rumen microorganisms, and the distribution of 75 Se in cow's and goat's milk. Methods of Se supplementation in Se-deficient areas are summarized and tests with 75 Se-labelled ruminal pellets in sheep and cattle are described. The Se toxicity syndrome is surveyed with respect to causative agents, symptomatology and gross pathology. Special reference is made to the blind staggers and the alkali disease types of selenosis. Isotope techniques are found to be less frequently applied in studies on Se toxicity than in Se deficiency studies. (author)

  3. SnSAG5 is an alternative surface antigen of Sarcocystis neurona strains that is mutually exclusive to SnSAG1.

    Science.gov (United States)

    Crowdus, Carolyn A; Marsh, Antoinette E; Saville, Willliam J; Lindsay, David S; Dubey, J P; Granstrom, David E; Howe, Daniel K

    2008-11-25

    Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). Previous work has identified a gene family of paralogous surface antigens in S. neurona called SnSAGs. These surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. However, SnSAG diversity exists in strains of S. neurona, including the absence of the major surface antigen gene SnSAG1. Instead, sequence for an alternative SnSAG has been revealed in two of the SnSAG1-deficient strains. Herein, we present data characterizing this new surface protein, which we have designated SnSAG5. The results indicated that the protein encoded by the SnSAG5 sequence is indeed a surface-associated molecule that has characteristics consistent with the other SAGs identified in S. neurona and related parasites. Importantly, Western blot analyses of a collection of S. neurona strains demonstrated that 6 of 13 parasite isolates express SnSAG5 as a dominant surface protein instead of SnSAG1. Conversely, SnSAG5 was not detected in SnSAG1-positive strains. One strain, which was isolated from the brain of a sea otter, did not express either SnSAG1 or SnSAG5. Genetic analysis with SnSAG5-specific primers confirmed the presence of the SnSAG5 gene in Western blot-positive strains, while also suggesting the presence of a novel SnSAG sequence in the SnSAG1-deficient, SnSAG5-deficient otter isolate. The findings provide further indication of S. neurona strain diversity, which has implications for diagnostic testing and development of vaccines against EPM as well as the population biology of Sarcocystis cycling in the opossum definitive host.

  4. Laser-assisted decay and optical spectroscopy studies of neutron-deficient thallium isotopes

    CERN Document Server

    Van Beveren, Céline; Huyse, Mark

    The neutron-deficient thallium isotopes with one proton less than the Z = 82 shell closure, are situated in an interesting region of the nuclear chart, notorious for intruder states and shape coexistence. Shape coexistence is the remarkable phenomenon in which two or more distinct types of deformation occur at low energy in the same atomic nucleus. Shape coexistence has been studied intensively, experimentally as well as theoretically in different nuclei in the light-lead region and the isomerism in the thallium isotopes was among the first indications of this phenomenon. Different shapes, whose structure has been linked to specific proton orbitals above and below the Z = 82 shell closure, are present at low energy in the neutron-deficient odd-mass thallium nuclei. In the odd-odd nuclei, the coupling of an unpaired proton and unpaired neutron gives rise to multiplets of low-lying states from which some can be isomeric. Since thallium has one proton missing in the major proton shell, and when approaching neutr...

  5. Gamma spectroscopy of multiple nucleon transfer reactions in Sn

    International Nuclear Information System (INIS)

    Grabowski, Z.W.; Mayer, R.H.; Fornal, B.; Nisius, D.T.; Bearden, I.G.; Daly, P.J.; Broda, R.; Carpenter, M.P.; Janssens, R.V.F.; Khoo, T.L.; Lauritsen, T.

    1992-01-01

    The decay of (πh 11/2 ) n yrast isomers was studied in a series of proton-rich N = 82 isotones culminating in determination of B(E2) values in 153 Lu and 154 Hf. In the N = 82 isotones however, it seems unlikely that the measurements could be extended beyond 154 Hf (n = 8). The opportunity to investigate the (h 11/2 ) n ) isomers across the whole h 11/2 subshell exists, at least in principle, in Sn isotopes where the counterpart νh 11/2 subshell is being filled with neutrons starting at 116 Sn. Before our measurements were initiated, the (νh 11/2 ) n 10 + isomers were known to exist in 116, 118, 120 Sn, where the νh 11/2 subshell begins to fill, and in 128,130 Sn at the other end. Important information, however, was missing about the 10 + isomers in 122,124,126 Sn where the long lifetimes are expected. The υ = 3 (h 11/2 ) isomers in odd tin isomers for A ≥ 119 were also not identified. A serious experimental difficulty in populating high spin states in heavier Sn isotopes is that they are not accessible by fusion-evaporation reactions. We decided to search for these missing tin isotopes among the products of heavy ion reactions on 122,124 Sn targets. Using this approach we were able to identify the isomeric decays and measure the lifetimes of the (νh 11/2 n ) υ = 2 isomeric states in 122,124 Sn. In odd tin isotopes we identified new I = 19/2 + yrast isomers in 119,121,123 Sn and measured their lifetimes. In addition (νh 11/2 ) n υ = 3, I = 27/2 - isomers in 119,121 Sn were observed for the first time

  6. Identification of new nuclei at and beyond the proton drip-line near the doubly-magic nucleus 100Sn

    International Nuclear Information System (INIS)

    Anne, R.; Auger, G.; Bazin, D.; Corre, J.M.; Hue, R.; Lewitowicz, M.; Saint-Laurent, M.G.; Rykaczewski, K.; Grzywacz, R.; Pfuetzner, M.; Zylicz, J.; Borrel, V.; Guillemaud-Mueller, D.; Mueller, A.C.; Pougheon, F.; Sorlin, O.; Fomichov, A.; Penionzhkevich, Y.; Lukyanov, S.; Tarasov, O.; Huyse, M.; Szerypo, J.; Wauters, J.

    1994-01-01

    The new neutron-deficient nuclei 103 Sb, 104 Sb, 98 In, 91 Pd, 89 Rh and 87 Ru have been identified among the quasi-fragmentation products of a 112 Sn beam (63 MeV/nucleon). The fragment identification based on energy-loss, total kinetic energy and time-of-flight measurements has been independently confirmed via observation of γ-radiation following the decay of known short-lived isomers. The region of known isotopes is extended to the predicted proton drip-line for indium and silver, and beyond it for antimony and rhodium. Tentative evidence for the existence of 105 Te, 99 Sn and 93 Ag is also presented. (authors). 28 refs., 2 figs

  7. Experimental investigation of decay properties of neutron deficient $^{116-118}$Ba isotopes and test of $^{112-115}$Ba beam counts

    CERN Multimedia

    We propose to study decay of neutron deficient isotopes $^{116-118}$Ba using Double Sided Silicon Strip Detector (DSSSD). To study delayed-proton and $\\alpha$-decay branching ratios of $^{116-118}$Ba are of special interest because of their vicinity to the proton drip line. The nuclear life-times and properties of the proton unstable states of Cs isotopes, populated through decay of $^{116-118}$Ba isotopes will be measured. In addition to that we propose beam development of $^{112-115}$Ba to study exotic decay properties of these neutron deficient nuclei and to search for super-allowed $\\alpha$-decay in future.

  8. Reactions of neutron-rich Sn isotopes investigated at relativistic energies at R{sup 3}B

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Fabia; Aumann, Thomas; Johansen, Jacob; Schrock, Philipp [IKP, TU Darmstadt (Germany); Boretzky, Konstanze [GSI Helmholtzzentrum (Germany); Collaboration: R3B-Collaboration

    2015-07-01

    Reactions of neutron-rich tin isotopes in a mass range of A=124 to A=134 have been measured at the R{sup 3}B setup at GSI in inverse kinematics. Due to the neutron excess, which results in a weaker binding of the valence neutrons such isotopes are expected to form a neutron skin. The investigation of this phenomenon is an important goal in nuclear-structure physics. Reactions of the tin isotopes with different targets have been performed kinematically complete. The taken data set therefore allows for the extraction of the neutron-skin thickness from two independent reaction channels. These are dipole excitations on the one hand and nuclear-induced reactions on the other hand. This contribution focuses on the latter mechanism. The analysis techniques which are used to extract the total charge-changing as well as the total neutron-removal cross section are presented using the example of {sup 124}Sn. The total neutron-removal cross section is of particular interest because of its high sensitivity to the neutron-skin thickness.

  9. Laser Spectroscopy Studies in the Neutron-Rich Sn Region

    CERN Multimedia

    Obert, J

    2002-01-01

    We propose to use the powerful laser spectroscopy method to determine the magnetic moment $\\mu$ and the variation of the mean square charge radius ($\\delta\\,\\langle$r$_{c}^{2}\\,\\rangle$) for ground and long-lived isomeric states of the Sn isotopes from A=125 to the doubly-magic $^{132}$Sn isotope and beyond. For these neutron-rich Sn nuclei, numerous $\\delta\\,\\langle$r$^{2}_{c}\\,\\rangle$ curves have already been calculated and the predictions depend upon the effective interactions used. Therefore, a study of the effect of the shell closure N=82 on the $\\delta\\,\\langle$r$^{2}_{c}\\,\\rangle$ values in the Z=50 magic nuclei is of great interest, especially because $^{132}$Sn is located far from the stability valley. It will help to improve the parameters of the effective interactions and make them more suitable to predict the properties of exotic nuclei. \\\\ \\\\The neutron-rich Sn isotopes produced with an uranium carbide target, are ionized using either a hot plasma ion source or the resonant ionization laser ion ...

  10. Fluorescent atom coincidence spectroscopy of extremely neutron-deficient barium isotopes

    International Nuclear Information System (INIS)

    Wells, S.A.; Evans, D.E.; Griffith, J.A.R.; Eastham, D.A.; Groves, J.; Smith, J.R.H.; Tolfree, D.W.L.; Warner, D.D.; Billowes, J.; Grant, I.S.; Walker, P.M.

    1988-01-01

    Fluorescent atom coincidence spectroscopy (FACS) has been used to measure the nuclear mean square radii and moments of the extremely neutron-deficient isotopes 120-124 Ba. At N=65 an abrupt change in nuclear mean square charge radii is observed which can be understood in terms of the occupation of the spin-orbit partner g 7/2 5/2[413] neutron and g 9/2 9/2[404] proton orbitals and the consequent enhancement of the n-p interaction. (orig.)

  11. Evolution of quadrupole and octupole collectivity north-east of $^{132}$ Sn: the even Te and Xe isotopes

    CERN Multimedia

    We propose to study excited states in isotopes north-east of the doubly-magic $^{132}$Sn by $\\gamma$-ray spectroscopy following "safe" Coulomb excitation. The experiment aims to the determine B(E2) and B(E3) values to follow the evolution of quadrupole and octupole collectivity when going away from the shell closures at Z = 50 and N = 82. The B(E2; 0$^+_{gs}$ $\\rightarrow$ 2$^+_{1}$) values in the even isotopes $^{138-144}$Xe have been measured at REX-ISOLDE and the systematic trend towards neutron-rich nuclei is well described even by an empirical Grodzins-type formula. An increasing dipole moment observed for $^{140,142}$Xe is interpreted as indirect signature of increasing octupole correlations peaking at N = 88. So far, no B(E3) values are known. In contrast to the Xe isotopes, the Te ones, in particular $^{136}$Te, are known for their notoriously irregular behaviour. In order to understand the nuclear structure also on a microscopic basis, the isotope $^{136}$Te with just one pair of protons and neutrons...

  12. Identification of new nuclei at and beyond the proton drip-line near the doubly-magic nucleus {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Anne, R; Auger, G; Bazin, D; Corre, J M; Hue, R; Lewitowicz, M; Saint-Laurent, M G [Grand Accelerateur National d` Ions Lourds (GANIL), 14 - Caen (France); Rykaczewski, K; Grzywacz, R [Warsaw Univ. (Poland). Inst. Fizyki Doswiadczalnej; [Grand Accelerateur National d` Ions Lourds (GANIL), 14 - Caen (France); Pfuetzner, M; Zylicz, J [Warsaw Univ. (Poland). Inst. Fizyki Doswiadczalnej; Borcea, C [Institute of Atomic Physics, Bucharest (Romania); Borrel, V; Guillemaud-Mueller, D; Mueller, A C; Pougheon, F; Sorlin, O [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Doerfler, T; Schmidt-Ott, W D [Goettingen Univ. (Germany); Fomichov, A; Penionzhkevich, Y [Joint Inst. for Nuclear Research, Dubna (Russian Federation); Lukyanov, S; Tarasov, O [Joint Inst. for Nuclear Research, Dubna (Russian Federation); [Grand Accelerateur National d` Ions Lourds (GANIL), 14 - Caen (France); Huyse, M; Szerypo, J; Wauters, J [Louvain Univ. (Belgium). Inst. for Nuclear- and Radiationphysics; Janas, Z; Keller, H; Schmidt, K [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)

    1994-12-31

    The new neutron-deficient nuclei {sup 103}Sb, {sup 104}Sb, {sup 98}In, {sup 91}Pd, {sup 89}Rh and {sup 87}Ru have been identified among the quasi-fragmentation products of a {sup 112}Sn beam (63 MeV/nucleon). The fragment identification based on energy-loss, total kinetic energy and time-of-flight measurements has been independently confirmed via observation of {gamma}-radiation following the decay of known short-lived isomers. The region of known isotopes is extended to the predicted proton drip-line for indium and silver, and beyond it for antimony and rhodium. Tentative evidence for the existence of {sup 105}Te, {sup 99}Sn and {sup 93}Ag is also presented. (authors). 28 refs., 2 figs.

  13. Low-lying electric-dipole strengths of Ca, Ni, and Sn isotopes imprinted on total reaction cross sections

    Science.gov (United States)

    Horiuchi, W.; Hatakeyama, S.; Ebata, S.; Suzuki, Y.

    2017-08-01

    Low-lying electric-dipole (E 1 ) strength of a neutron-rich nucleus contains information on neutron-skin thickness, deformation, and shell evolution. We discuss the possibility of making use of total reaction cross sections on 40Ca, 120Sn, and 208Pb targets to probe the E 1 strength of neutron-rich Ca, Ni, and Sn isotopes. They exhibit large enhancement of the E 1 strength at neutron number N >28 , 50, and 82, respectively, due to a change of the single-particle orbits near the Fermi surface participating in the transitions. The density distributions and the electric-multipole strength functions of those isotopes are calculated by the Hartree-Fock+BCS and the canonical-basis-time-dependent-Hartree-Fock-Bogoliubov methods, respectively, using three kinds of Skyrme-type effective interaction. The nuclear and Coulomb breakup processes are respectively described with the Glauber model and the equivalent photon method in which the effect of finite-charge distribution is taken into account. The three Skyrme interactions give different results for the total reaction cross sections because of different Coulomb breakup contributions. The contribution of the low-lying E 1 strength is amplified when the low-incident energy is chosen. With an appropriate choice of the incident energy and target nucleus, the total reaction cross section can be complementary to the Coulomb excitation for analyzing the low-lying E 1 strength of unstable nuclei.

  14. Shape coexistence measurements in even-even neutron-deficient polonium isotopes by Coulomb excitation, using REX-ISOLDE and the Ge MINIBALL array

    CERN Multimedia

    Butler, P; Bastin, B; Kruecken, R; Voulot, D; Rahkila, P J; Orr, N A; Srebrny, J; Grahn, T; Clement, E; Paul, E S; Gernhaeuser, R A; Dorsival, A; Diriken, J V J; Huyse, M L; Iwanicki, J S

    The neutron-deficient polonium isotopes with two protons outside the closed Z=82 shell represent a set of nuclei with a rich spectrum of nucleus structure phenomena. While the onset of the deformation in the light Po isotopes is well established experimentally, questions remain concerning the sign of deformation and the magnitude of the mixing between different configurations. Furthermore, controversy is present with respect to the transition from the vibrational-like character of the heavier Po isotopes to the shape coexistence mode observed in the lighter Po isotopes. We propose to study this transition in the even-mass neutron-deficient $^{198,200,202}$Po isotopes by using post-accelerated beams from REX-ISOLDE and "safe"-energy Coulomb excitation. $\\gamma$- rays will be detected by the MINIBALL array. The measurements of the Coulomb excitation differential cross section will allow us to deduce both the transition and diagonal matrix elements for these nuclei and, combined with lifetime measurements, the s...

  15. Giant monopole resonance in even-A Cd isotopes, the asymmetry term in nuclear incompressibility, and the 'softness' of Sn and Cd nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Patel, D. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Garg, U., E-mail: garg@nd.edu [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Akimune, H. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Berg, G.P.A. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Harakeh, M.N. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); Itoh, M. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Kawabata, T. [Center for Nuclear Studies, University of Tokyo, Tokyo 113-0033 (Japan); Kawase, K. [Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047 (Japan); Nayak, B.K. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Ohta, T. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Ouchi, H. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Piekarewicz, J. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Uchida, M. [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8850 (Japan); Yoshida, H.P. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Yosoi, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan)

    2012-12-05

    The isoscalar giant monopole resonance (ISGMR) in even-A Cd isotopes has been studied by inelastic {alpha}-scattering at 100 MeV/u and at extremely forward angles, including 0 Degree-Sign . The asymmetry term in the nuclear incompressibility extracted from the ISGMR in Cd isotopes is found to be K{sub {tau}}=-555{+-}75 MeV, confirming the value previously obtained from the Sn isotopes. ISGMR strength has been computed in relativistic RPA using NL3 and FSUGold effective interactions. Both models significantly overestimate the centroids of the ISGMR strength in the Cd isotopes. Combined with other recent theoretical effort, the question of the 'softness' of the open-shell nuclei in the tin region remains open still.

  16. Fragmentation of two-quasiparticle states in 92Zr and even-even Sn isotopes

    International Nuclear Information System (INIS)

    Solov'ev, V.G.; Stoyanova, O.; Voronov, V.V.

    1981-01-01

    The fragmentation of two-quasiparticle states in doubly even spherical nuclei is calculated within the quasiparticle-phonon nuclear model. The fragmentation is due to the interactions leading to the formation of phonons and to the quasiparticle-phonon interaction. The spectroscopic factors for the ''particle-valence particle'' states in 92 Zr are calculated. The agreement with the experimental data of the reaction 91 Zr(d, p) 92 Zr is obtained. The centroid energy Esub(jjsub(0)) and width GITAsub(jjsub(0)) are calculated for the configurations excited in the (p, d) reactions on odd-A isotopes of Cd, Sn and Te. It is shown that the valence particle-hole lgsub(9/2) configuration is localized at the excitation energies of 7-9 MeV. The corresponding experimental data are well described

  17. 0(gs)+ -->2(1)+ transition strengths in 106Sn and 108Sn.

    Science.gov (United States)

    Ekström, A; Cederkäll, J; Fahlander, C; Hjorth-Jensen, M; Ames, F; Butler, P A; Davinson, T; Eberth, J; Fincke, F; Görgen, A; Górska, M; Habs, D; Hurst, A M; Huyse, M; Ivanov, O; Iwanicki, J; Kester, O; Köster, U; Marsh, B A; Mierzejewski, J; Reiter, P; Scheit, H; Schwalm, D; Siem, S; Sletten, G; Stefanescu, I; Tveten, G M; Van de Walle, J; Van Duppen, P; Voulot, D; Warr, N; Weisshaar, D; Wenander, F; Zielińska, M

    2008-07-04

    The reduced transition probabilities, B(E2; 0(gs)+ -->2(1)+), have been measured in the radioactive isotopes (108,106)Sn using subbarrier Coulomb excitation at the REX-ISOLDE facility at CERN. Deexcitation gamma rays were detected by the highly segmented MINIBALL Ge-detector array. The results, B(E2;0(gs)+ -->2(1)+)=0.222(19)e2b2 for 108Sn and B(E2; 0(gs)+-->2(1)+)=0.195(39)e2b2 for 106Sn were determined relative to a stable 58Ni target. The resulting B(E2) values are approximately 30% larger than shell-model predictions and deviate from the generalized seniority model. This experimental result may point towards a weakening of the N=Z=50 shell closure.

  18. Isotopically modified compounds

    International Nuclear Information System (INIS)

    Kuruc, J.

    2009-01-01

    In this chapter the nomenclature of isotopically modified compounds in Slovak language is described. This chapter consists of following parts: (1) Isotopically substituted compounds; (2) Specifically isotopically labelled compounds; (3) Selectively isotopically labelled compounds; (4) Non-selectively isotopically labelled compounds; (5) Isotopically deficient compounds.

  19. Nanoscale Cross-Point Resistive Switching Memory Comprising p-Type SnO Bilayers

    KAUST Repository

    Hota, Mrinal Kanti; Hedhili, Mohamed N.; Wang, Qingxiao; Melnikov, Vasily; Mohammed, Omar F.; Alshareef, Husam N.

    2015-01-01

    Reproducible low-voltage bipolar resistive switching is reported in bilayer structures of p-type SnO films. Specifically, a bilayer homojunction comprising SnOx (oxygen-rich) and SnOy (oxygen-deficient) in nanoscale cross-point (300 × 300 nm2

  20. Collinear laser spectroscopy on radioactive neutron-deficient lead and thallium isotopes

    International Nuclear Information System (INIS)

    Menges, R.

    1989-02-01

    The systematic study of the isotope shift in the neighbourhood of the closed shells was extended in this thesis to Z = 82. The elements lead and thallium were measured up to the mass 190 and 188 and the nuclear moments determined together with the change of the mean square charge radius. The accumulating of the recoil nuclei formed by heavy ion reactions in the bunched ion source of the GSI mass separator could be used in order to study the low-spin isomers with I = 2 of the neutron-deficient thallium isotopes up to A = 190. It is a clearly recognizable isomer shift against the I = 7 isomers shown which changes at A = 194 the sign. A phenomenon which also exists in the element mercury, but for which no sufficient explanation exists. The magnetic moments of the thallium isotopes complete the analysis of Ekstroem (1976) and confirm the choice of the sign of the magnetic moments of the I = 2 isomers. The application of the additivity rule to the odd-odd nuclei shows qualitatively good agreement with the experiment and confirms so the assignment of the configuration of the contributing nuclear states. The quadrupole moments show a slight oblate deformation of the 9/2 - intruder states. The moments of the lead isotopes show pronounced one-particle character and by this the nearly spherical shape of nuclei with closed proton shell. The deviation from the linear slope of the mean square radius of the lead isotopes onsetting at A = 194 cannot be explained by the mixing of the 0 1 + ground state with the deformed 0 2 + intruder state. The odd - even staggering and the buckling of the charge radii at the shell closure are very well reproduced by Hartree-Fock calculations which regard the 3- and 4-particle interactions in the nucleus. (orig.) [de

  1. Mixing of fluids in hydrothermal ore-forming (Sn,W) systems: stable isotope and rare earth elements data

    Science.gov (United States)

    Sushchevskaya, T. M.; Popova, J. A.; Velivetskaya, T. A.; Ignatiev, A. V.; Matveeva, S. S.; Limantseva, O. A.

    2012-04-01

    Experimental and physico-chemical modeling data witness to important role of mixing of different type of fluids during tin and tungsten ore formation in hydrothermal systems. Mixing of magmatogeneous fluids, exsolved from granite melts, with exogenic, initially meteoric waters in hydrothermal ore-forming systems may change chemical composition of ore-forming fluid, causing cassiterite and/or wolframite precipitation (Heinrich, 1990; Sushchevskaya, Ryzhenko, 2002). We studied the process of genetically different fluids mixing for two economic Sn-W deposits, situated in the Iultin ore region (North-East of Russia, Chukotka Penninsula). The Iultin and Svetloe deposits are located in the apical parts of close situated leucogranite stocks, formed at the final stage of the Iultin complex emplacement. Both deposits are composed of a series of quartz veins among the flyschoid rocks (T 1-2), cut by the dikes (K1) of lamprophyre, granodiorite porphyre and alpite. The veins of the deposits are dominated by the productive quartz-wolframite-cassiterite-arsenopyrite-muscovite mineral assemblage. Topaz, beryl, fluorite, and albite occur sporadically. The later sulfide (loellingite-stannite-chalcopyrite) and quartz-fluorite-calcite assemblages show insignificant development. The preore quartz veinlets in host hornfels contain disseminated iron sulfides, chalcopyrite, muscovite. Isotopic (H, O, Ar) study of minerals, supplemented by oxygen isotope data of host granites and metamorphic rocks gave us possibility to conclude, that at the Iultin and the Svetloye deposits fluid mixing was fixed on the early stages of deposit formation and could be regarded as probable cause of metal (W, Sn) precipitation. During postore time the intensive involvement of isotopically light exogenic waters have changed: a) the initial character of oxygen isotope zonality; b) the initial hydrogen isotope composition of muscovites, up to meteoric calculated values for productive fluid (while the δ18O

  2. Shape coexistence in the neutron-deficient mercury isotopes studied through Coulomb excitation

    CERN Document Server

    Bree, Nick

    This thesis describes the analysis and results of a series of Coulomb-excitation experiments on even-even neutron-deficient mercury isotopes aimed at obtaining a more detailed description of shape coexistence. Two experimental campaigns have been undertaken in the Summer of 2007 and 2008. Pure beams of 182,184,186,188Hg were produced and accelerated at the REX-ISOLDE radioactive-beam facility, located at CERN (Geneva, Switzerland). The beams were guided to collide with a stable target to induce Coulomb excitation. The scattered particles were registered by a double-sided silicon strip detector, and the emitted gamma rays by the MINIBALL gamma-ray spectrometer. The motivation to study these mercury isotopes, focused around shape coexistence in atomic nuclei, is addressed in chapter 1, as well as an overview of the knowledge in this region of the nuclear chart. A theoretical description of Coulomb excitation is presented in the second chapter, while the third chapter describes the setup employed for the experim...

  3. Neutron emission spectra of excited 126–140Sn nuclei

    International Nuclear Information System (INIS)

    Aggarwal, Mamta; Rajasekaran, M.

    2004-01-01

    We investigate one-neutron and two-neutron emission from 132 Sn and its neighboring isotopes due to thermal excitation. The rotational states of 132 Sn at different temperatures are investigated. The effects of separation energy and thermal excitation energy on neutron emission probability are studied. (author)

  4. Beta-decay studies near 100Sn

    International Nuclear Information System (INIS)

    Rykaczewski, Krzysztof Piotr; Karny, M.; Batist, L.; Banu, A.; Becker, F.; Blazhev, A.; Burkard, K.; Bruchle, W.; Doring, J.; Faestermann, T.; Gorska, M.; Grawe, H.; Janas, Z.; Jungclaus, A.; Kavatsyuk, M.; Kavatsyuk, O.; Kirchner, R.; La Commara, M.; Mandal, S.; Mazzocchi, C.; Miernik, K.; Mukha, I.; Muralithar, S.; Plettner, C.; Plochocki, A.; Roeckl, E.; Romoli, M.; Schadel, M.; Schmidt, K.; Schwengner, R.; Zylicz, J.

    2005-01-01

    The β-decay of 102 Sn was studied by using high-resolution germanium detectors as well as a Total Absorption Spectrometer (TAS). A decay scheme has been constructed based on the γ-γ coincidence data. The total experimental Gamow-Teller strength B GT exp of 102 Sn was deduced from the TAS data to be 4.2(9). A search for β-delayed γ-rays of 100 Sn decay remained unsuccessful. However, a Gamow-Teller hindrance factor h = 2.2(3), and a cross-section of about 3nb for the production of 100 Sn in fusion-evaporation reaction between 58 Ni beam and 50 Cr target have been estimated from the data on heavier tin isotopes. The estimated hindrance factor is similar to the values derived for lower shell nuclei

  5. The dipole response of {sup 132}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Schrock, Philipp; Aumann, Thomas; Johansen, Jacob; Schindler, Fabia [IKP, TU Darmstadt (Germany); Boretzky, Konstanze [GSI Helmholtzzentrum (Germany); Rossi, Dominic [Michigan State University (United States); Collaboration: R3B-Collaboration

    2015-07-01

    The Isovector Giant Dipole Resonance (IVGDR) is a well-known collective excitation in which all protons oscillate against all neutrons of a nucleus. In neutron-rich nuclei an additional low-lying dipole excitation occurs, often denoted as Pygmy Dipole Resonance (PDR). To study the PDR in exotic Sn-isotopes, an experiment has been successfully performed with the upgraded R{sup 3}B-LAND setup at GSI. The complete-kinematics measurement of all reaction participants allows for the reconstuction of the excitation energy and, hence, the extraction of the dipole strength. Presented are the main features of the experiment, the analysis concept and the current status of the analysis of the dipole response of the doubly-magic isotope {sup 132}Sn.

  6. Transfer reactions and multiple Coulomb excitation in the $^{100}$Sn Region

    CERN Multimedia

    It is proposed to continue our REX-ISOLDE program in the $^{100}$Sn region at HIE-ISOLDE at ~5 MeV/u. Earlier measurements, with a precision of 10-20%, at 3 MeV/u with REX-ISOLDE point to a deviation between the measured B(E2) values for the first excited 2$^{+}$ states in $^{110,108,106}$Sn compared to theoretical predictions. In addition, the trend of B(E2) values for the lighter isotopes, in particular $^{106}$Sn, appear to differ between low- and high-energy measurements. In line with our letter-of-intent we aim in a first step to address the electromagnetic properties of the first 2$^{+}$and 4$^{+}$ states in $^{110,108,106}$Sn using Coulomb excitation. In these measurements we will directly access the lifetimes of the first excited 4$^{+}$ states in $^{110,108,106}$Sn for the first time. The yield of $^{104}$Sn from the LaC$_{x}$ target will be revisited to clarify if the new solid state RILIS gives sufficient yield to expand the measurements to this isotope. Following this proposal we plan similar meas...

  7. Yields of the rare-earth neutron-deficient isotopes in the reactions of Mo isotopes with 40Ca ions

    International Nuclear Information System (INIS)

    Adam, J.; Chaloun, P.; Gangrskij, Yu.P.

    1999-01-01

    The results of the joint Russian-Chinese experiment on the measurements of the reaction cross sections of the rare-earth neutron-deficient isotopes production and the study of their decay scheme are presented. The studied nuclides were obtained in the reactions 92 Mo + 40 Ca and 97 Mo + 40 Ca on the 4-meter cyclotron of the Flerov Laboratory of Nuclear Reactions, JINR. The recoil nuclei were stopped in the inert gas and transported by the gas flow to the detectors. The single and coincidence spectra of γ-, x-rays and delayed protons were measured. The enhanced yield of the reactions with the charge particle evaporation was observed

  8. Controlled synthesis of the antiperovskite oxide superconductor Sr3‑x SnO

    Science.gov (United States)

    Hausmann, J. N.; Oudah, M.; Ikeda, A.; Yonezawa, S.; Maeno, Y.

    2018-05-01

    A large variety of perovskite oxide superconductors are known, including some of the most prominent high-temperature and unconventional superconductors. However, superconductivity among the oxidation state inverted material class, the antiperovskite oxides, was recently reported for the first time. In this superconductor, Sr3‑x SnO, the unconventional ionic state Sn4‑ is realized and possible unconventional superconductivity due to a band inversion has been discussed. Here, we discuss an improved facile synthesis method, making it possible to control the strontium deficiency in Sr3‑x SnO. Additionally, a synthesis method above the melting point of Sr3SnO is presented. We show temperature dependence of magnetization and electrical resistivity for superconducting strontium deficient Sr3‑x SnO (T c ∼ 5 K) and for Sr3SnO without a superconducting transition in alternating current susceptibility down to 0.15 K. Further, we reveal a significant effect of strontium raw material purity on the superconductivity and achieve substantially increased M/M Meissner (∼1) compared to the highest value reported so far. More detailed characterizations utilizing powder x-ray diffraction and energy-dispersive x-ray spectroscopy show that a minor cubic phase, previously suggested to be another Sr3‑x SnO phase with a slightly larger lattice parameter, is SrO. The improved characterization and controlled synthesis reported herein enable detailed investigations on the superconducting nature and its dependency on the strontium deficiency in Sr3‑x SnO.

  9. Theoretical band structure of the superconducting antiperovskite oxide Sr3-xSnO

    Science.gov (United States)

    Ikeda, Atsutoshi; Fukumoto, Toshiyuki; Oudah, Mohamed; Hausmann, Jan Niklas; Yonezawa, Shingo; Kobayashi, Shingo; Sato, Masatoshi; Tassel, Cédric; Takeiri, Fumitaka; Takatsu, Hiroshi; Kageyama, Hiroshi; Maeno, Yoshiteru

    2018-05-01

    In order to investigate the position of the strontium deficiency in superconductive Sr3-xSnO, we synthesized and measured X-ray-diffraction patterns of Sr3-xSnO (x ∼ 0.5). Because no clear peaks originating from superstructures were observed, strontium deficiency is most likely to be randomly distributed. We also performed first-principles band-structure calculations on Sr3-xSnO (x = 0, 0.5) using two methods: full-potential linearized-augmented plane-wave plus local orbitals method and the Korringa-Kohn-Rostoker Green function method combined with the coherent potential approximation. We revealed that the Fermi energy of Sr3-xSnO in case of x ∼ 0.5 is about 0.8 eV below the original Fermi energy of the stoichiometric Sr3SnO, where the mixing of the valence p and conduction d orbitals are considered to be small.

  10. Quality control for a group of pyrophosphate-Sn kits

    International Nuclear Information System (INIS)

    Isaac, M.; Gamboa, R.; Hernandez, I.; Leyva, R.; Turino, D.

    1994-01-01

    The quality control for a group of Pyrophosphate-Sn kits for labeling with 99 m Tc is carry out at the Isotope Center. A general discussion takes place about the instrumental techniques for the determination of the kit constituent such as ligands, Sn(II), water, etc, as well as the control table for the evaluation of the warranty time. (author). 5 refs, 4 figs

  11. Isotopic distribution of the projectile-like products in the reaction 36Ar + 124Sn at 35 MeV/u

    International Nuclear Information System (INIS)

    Xiao Zhigang; Jin Genming; Wu Heyu; Hu Rongjiang; Wang Hongwei; Li Zuyu; Duan Limin; Wang Sufang; Wei Zhiyong; Zhang Baoguo; Liu Jianye; Zhu Yongtai

    2003-01-01

    The projectile-like products at 5.3 degree in the reaction 35 MeV/u 36 Ar + 124 Sn were inclusively measured with good isotopic identification. With increasing kinetic energy, the average N/Z ratio of the products gradually decreases, approaching to that of the projectile. It is shown from the isospin dependent quantum mechanics (IQMD) that with the increasing of reaction time, the average kinetic energy of the projectile-like products decreases, while the N/Z ratio increases gradually. Moreover, the isotropic composition is obviously dependent on the impact parameter, and the N/Z radio is becoming smaller with increasing collision centrality

  12. Etude de noyaux riches en neutrons dans la région du coeur doublement magique de ¹³²Sn

    OpenAIRE

    Gey , Guillaume

    2014-01-01

    Evolution of nuclear structure in the vicinity of the doubly magic nuclei 132Sn will be discussed in this work, through the spectroscopy of 136Sb, 136Sn and 138Sn isotopes. Several Sb and Sn known isotopes beyond the Z=50 and N=82 shell closures will be briefly presented in the first chapter, aswell as some of the problems arising from the current shell model descritpion of nuclei in this region. Reader will also find in the same chapter a brief description of the most important tools needed ...

  13. Central {sup 112}Sn + {sup 58}Ni, {sup 124}Sn + {sup 64}Ni collisions in the Reverse Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Geraci, E.; Bruno, M.; D' Agostino, M.; Vannini, G. [Bologna Univ., Dipartimento di Fisica (Italy); Anzalone, A.; Baran, V.; Bonasera, A.; Cavallaro, S.; Colonna, M.; Di Toro, M.; Giustolisi, F.; Iacono-Manno, M.; La Guidara, E.; Lanzalone, G.; Porto, F.; Russotto, P.; Maiolino, C.; Sperduto, M.I. [Catania Univ., INFN-LNS and Dipartimento di Fisica e Astronomia (Italy); Alderighi, M.; Bartolucci, M.; Sechi, G. [INFN and Istituto di Fisica Cosmica, CNR, Milano (Italy); Auditore, L.; Trifiro, A.; Rimarchi, M. [Messina Univ., INFN and Dipartimento di Fisica (Italy); Berceanu, I.; Petrovici, M.; Simion, S. [Institute for Physics and Nuclear Engineering, Bucharest (Romania); Guazzoni, P.; Russo, S.; Manfredi, G.; Zetta, L. [Milano Univ., INFN and Dipartimento di Fisica (Italy); Blicharska, J.; Grzeszczuk, A.; Kowalski, S.; Paduszynski, T.; Zipper, W. [Silesia Univ., Institute of Physics, Katowice (Poland); Borderie, B.; Le Neindre, N.; Rivet, M.F. [Institut de Physique nucleaire, IN2P3-CNRS, 91 - Orsay (France); Bougault, B.R.; Steckmeyer, J.C. [Caen Univ., LPC, ENSI, 14 (France); Brzychczyk, J.; Majka, Z. [Jagellonian Univ., M.Smoluchowski Institute of Physics, Cracow (Poland); Cardella, G.; Filippo, E. de; Lanzano, G.; Li, S.; Lo Nigro, S.; Pagano, A.; Papa, M.; Pirrone, S.; Politi, G. [Catania Univ., INFN and Dipartimento di Fisica e Astronomia (Italy); Chbihi, A.; Wieleczko, J.P. [GANIL, CEA, IN2P3-CNRS, 14 - Caen (France); Cibor, J. [H. Niewodniczanski Institute of Nuclear Physics, Cracov (Poland); Guinet, D. [Institut de Physique nucleaire, IN2P3-CNRS, 69 - Lyon (France); Wu, H.; Xiao, Z. [Institute of Modern Physics Lanzhou (China); Piasecki, E. [Warsaw Univ., Institute of Experimental Physics (Poland); Rosato, E.; Vigilante, M. [Napoli Univ., INFN and Dipartimento di Fisica (Italy); Wilczynski, J. [Institute for Nuclear Studies, Otwock-Swierk (Poland)

    2003-07-01

    {sup 112}Sn + {sup 58}Ni and {sup 124}Sn + {sup 64}Ni reactions at 35 AMeV incident energy were studied using the 688 Si-CsI(Tl) telescopes of the forward part (1 {<=} {theta} {<=} 30 degrees) of CHIMERA multi-detector. The most central part of the total measured cross section was selected by means of a multidimensional analysis of the experimental observables. The characteristics of the source formed in the central collisions, as size, temperature and volume, were inspected. The detected isotopes of light fragments (3 {<=} Z {<=} 8) provided information on breakup temperatures of the emitting sources. The space-time structure of these sources was deduced from the two-fragment velocity correlation functions. Isotope yield ratios were used to extract the freeze-out unbound relative neutron and proton densities and the neutron to proton density of both studied reactions, indicating for a possible isospin distillation mechanism. (authors)

  14. Alpha decay of neutron-deficient isotopes with 52isotopes /sup 106/Te (T/sub 1/2/=60 mu s) and /sup 110/Xe

    CERN Document Server

    Schardt, D; Kirchner, R; Klepper, O; Kurcewicz, W; Roeckl, E; Tidemand-Petersson, P

    1981-01-01

    Using /sup 58/Ni(/sup 58/Ni, xpyn) reactions and on-line mass separation, the alpha -decays of very neutron-deficient isotopes of tellurium, iodine, xenon and cesium were studied. The new isotopes /sup 106/Te (T/sub 1/2/=60/sub -10//sup +30/ mu s) and /sup 110/Xe were identified by their alpha -lines of 4160+or-30 keV and 3737+or-30 keV energy, respectively, with the genetic relationship between the two successive alpha -decays being verified experimentally, while for several other alpha -decaying isotopes more precise data were obtained. The observed alpha -decay properties are discussed within the systematics of energy and reduced width. (19 refs).

  15. The Material Properties of CsSnBr3 and CsBr:Sn-1% and Their Potential as Scintillator Detector Material

    Science.gov (United States)

    2010-03-01

    Iodide or Cesium Iodide are the benchmarks for ease of use and quick identification of isotope species. This research aims to explore Cesium Bromide doped...oxidation states of 3+, 4+, 5+ and 6+ were used to identify the Pu pollution in the Rocky Flats area. The identification of the Pu4+ oxidation state...point was causing the normalization of the spectra to be much higher than what it should be. The XANES structures lineup showing the Sn in the CsSnBr3

  16. Investigations on the indium-113m isotope generators

    International Nuclear Information System (INIS)

    Oniciu, L.; Veglia, A.

    1975-01-01

    Methods for the determination of sup(113Sn) in the eluate of an sup(113m)In generator are proposed. The techniques for the chemical and radionuclidic purity analysis of the eluate are also described: colorimetry, gamma-ray spectrometry, thin-film chromatography, and electrophoretic separation were used. Two generators of different origins were studied. The presence of the isotopes sup(113)Sn, sup(125)Sb, sup(125m)Te, and the elements Zr, Si and Fe were detected in the eluate. Recommendations for the use of these isotope cows are made. (G.Gy.)

  17. Thermoelectric Properties in the TiO2/SnO2 System

    Science.gov (United States)

    Dynys, F.; Sayir, A.; Sehirlioglu, A.; Berger, M.

    2009-01-01

    Nanotechnology has provided a new interest in thermoelectric technology. A thermodynamically driven process is one approach in achieving nanostructures in bulk materials. TiO2/SnO2 system exhibits a large spinodal region with exceptional stable phase separated microstructures up to 1400 C. Fabricated TiO2/SnO2 nanocomposites exhibit n-type behavior with Seebeck coefficients greater than -300 .V/K. Composites exhibit good thermal conductance in the range of 7 to 1 W/mK. Dopant additions have not achieved high electrical conductivity (<1000 S/m). Formation of oxygen deficient composites, TixSn1-xO2-y, can change the electrical conductivity by four orders of magnitude. Achieving higher thermoelectric ZT by oxygen deficiency is being explored. Seebeck coeffcient, thermal conductivity, electrical conductance and microstructure will be discussed in relation to composition and doping.

  18. Nuclear charge radii and nuclear moments of neutron deficient Ba isotopes from high resolution laser spectroscopy

    International Nuclear Information System (INIS)

    Nowicki, G.; Bekk, K.; Goering, S.; Hanser, A.; Rebel, H.; Schatz, G.

    1978-07-01

    Isotope shifts and hyperfine structure of the BaI 6s 2 1 S 0 -6s6p 1 P 1 transitions (lambda = 553.6 nm) in neutron deficient Ba nuclides (N 131 Ba, 128 Ba, in addition to remeasurements of all stable Ba nuclides. The extracted values of delta 2 >, the observed odd-even staggering and the nuclear moments are discussed in the light of other theoretical and experimental nuclear structure studies of the region 50 [de

  19. Effective charges in nuclei in the vicinity of $^{100}SN$

    CERN Document Server

    Ekström, Andreas

    The shell structure of atomic nuclei far from the line of beta-stability and the properties of the nucleon-nucleon interaction in exotic isotopes are not well known. The development of radioactive ion beams (RIBs) puts certain unexplored regions of the nuclear chart within reach of detailed experimental investigations. The low-energy nuclear structure of the unstable isotopes 106,108,110Sn, 100,102,104Cd, and 106,108In have been studied using sub-barrier Coulomb excitation of postaccelerated RIBs. The experiments were carried out at the REX-ISOLDE facility at CERN. The deduced transition probabilities - B(E2) values - provide a detailed benchmark of modern models of the nucleon-nucleon interaction. The B(E2) values between the 0+ ground states and the first excited 2+ states in the Sn and Cd isotopes were compared with shell-model calculations. These are based on effective interactions derived from renormalized multi-meson and QCD-based nucleon-nucleon potentials. In order to reproduce the experimental result...

  20. Spectroscopy of heavy nuclei by configuration mixing of symmetry restored mean-field states: shape coexistence in neutron-deficient Pb isotopes

    International Nuclear Information System (INIS)

    Bender, M.; Heenen, P.H.; Bonche, P.; Duguet, T.

    2003-01-01

    We study shape coexistence and low-energy excitation spectra in neutron-deficient Pb isotopes using configuration mixing of angular-momentum and particle-number projected self-consistent mean-field states. The same Skyrme interaction SLy6 is used everywhere in connection with a density-dependent zero-range pairing force. (orig.)

  1. Certification of butyltins and phenyltins in marine sediment certified reference material by species-specific isotope-dilution mass spectrometric analysis using synthesized {sup 118}Sn-enriched organotin compounds

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Kazumi; Takatsu, Akiko; Watanabe, Takuro; Aoyagi, Yoshie; Yarita, Takashi; Okamoto, Kensaku; Chiba, Koichi [National Institute of Advanced Industrial Science and Technology (AIST), Environmental Standard Section, National Metrology Institute of Japan (NMIJ), Tsukuba, Ibaraki (Japan)

    2007-04-15

    A new marine sediment certified reference material, NMIJ CRM 7306-a, for butyltin and phenyltin analysis has been prepared and certified by the National Metrological Institute of Japan at the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). Candidate sediment material was collected at a bay near industrial activity in Japan. After air-drying, sieving, and mixing the material was sterilized with {gamma}-ray irradiation. The material was re-mixed and packaged into 250 glass bottles (15 g each) and these were stored in a freezer at -30 C. Certification was performed by use of three different types of species-specific isotope-dilution mass spectrometry (SSID-MS) - SSID-GC-ICP-MS, SSID-GC-MS, and SSID-LC-ICP-MS, with {sup 118}Sn-enriched organotin compounds synthesized from {sup 118}Sn-enriched metal used as a spike. The {sup 118}Sn-enriched mono-butyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were synthesized as a mixture whereas the {sup 118}Sn-enriched di-phenyltin (DPhT) and triphenyltin (TPhT) were synthesized individually. Four different extraction methods, mechanical shaking, ultrasonic, microwave-assisted, and pressurized liquid extraction, were adopted to avoid possible analytical bias caused by non-quantitative extraction and degradation or inter-conversion of analytes in sample preparations. Tropolone was used as chelating agent in all the extraction methods. Certified values are given for TBT 44{+-}3 {mu}g kg{sup -1} as Sn, DBT 51 {+-} 2 {mu}g kg{sup -1} as Sn, MBT 67 {+-} 3 {mu}g kg{sup -1} as Sn, TPhT 6.9 {+-} 1.2 {mu}g kg{sup -1} as Sn, and DPhT 3.4 {+-} 1.2 {mu}g kg{sup -1} as Sn. These levels are lower than in other sediment CRMs currently available for analysis of organotin compounds. (orig.)

  2. Performance of the multiple target He/PbI sub 2 aerosol jet system for mass separation of neutron-deficient actinide isotopes

    CERN Document Server

    Ichikawa, S; Asai, M; Haba, H; Sakama, M; Kojima, Y; Shibata, M; Nagame, Y; Oura, Y; Kawade, K

    2002-01-01

    A multiple target He/PbI sub 2 aerosol jet system coupled with a thermal ion source was installed in the isotope separator on line (JAERI-ISOL) at the JAERI tandem accelerator facility. The neutron-deficient americium and curium isotopes produced in the sup 2 sup 3 sup 3 sup , sup 2 sup 3 sup 5 U( sup 6 Li, xn) and sup 2 sup 3 sup 7 Np( sup 6 Li, xn) reactions were successfully mass-separated and the overall efficiency including the ionization of Am atoms was evaluated to be 0.3-0.4%. The identification of a new isotope sup 2 sup 3 sup 7 Cm with the present system is reported.

  3. Decay studies of neutron-deficient lawrencium isotopes

    International Nuclear Information System (INIS)

    Antalic, S.; Saro, S.; Streicher, B.; Venhart, M.; Hessberger, F.P.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Hofmann, S.; Kuusiniemi, P.; Leino, M.; Nishio, K.; Sulignano, B.

    2008-01-01

    The radioactive decay of the isotopes 254-256 Lr and their daughter products was investigated by means of α, prompt α-γ and delayed conversion electron-γ coincidence spectroscopy. The isotopes were produced using the reaction 48 Ca+ 209 Bi. (orig.)

  4. Identification of 100Sn and other proton drip-line nuclei in the reaction 112Sn + natNi at 63 MeV/nucleon

    International Nuclear Information System (INIS)

    Lewitowicz, M.; Anne, R.; Auger, G.; Bazin, D.; Corre, J.M.; Borcea, C.; Borrel, V.; Fomichov, A.; Grzywacz, R.; and others.

    1996-01-01

    The doubly-magic nucleus 100 Sn and six new neutron-deficient nuclei in the A∼100 region were identified in the reaction 112 Sn + nat Ni at 63 MeV/nucleon. The experiment was carried out using the high acceptance device SISSI and the Alpha and LISE3 spectrometers at GANIL. The identification of the reaction products (A, Z and Q) was made using the measurements of time-of-flight, energy-loss and kinetic energy. (author)

  5. Pressure dependence of magnetic ordering temperatures of rare earth-Sn/sub 3/ compounds

    Energy Technology Data Exchange (ETDEWEB)

    Foner, S [Massachusetts Inst. of Tech., Cambridge (USA). Francis Bitter National Magnet Lab.

    1979-12-01

    Measurements of the hydrostatic pressure dependence of the Neel temperatures, Tsub(N), are reported for PrSn/sub 3/, NdSn/sub 3/, GdSn/sub 3/ and CeIn/sub 3/. Tsub(N) is found to increase with applied pressure for PrSn/sub 3/ and NdSn/sub 3/, whereas Tsub(N) is pressure independent within experimental error for GdSn/sub 3/ and CeIn/sub 3/. Slightly Sn-deficient RESn/sub 3/ (RE = rare earth) compounds are found consistently to be weakly ferromagnetic. The physical properties of the RESn/sub 3/ compounds exhibit analogies with the corresponding properties of dilute superconducting (LaRE)Sn/sub 3/ alloys. The high pressure data for PrSn/sub 3/ and CeIn/sub 3/ are qualitatively consistent with a 'Kondo necklace' model for magnetically ordered RE compounds with unstable 4f shells.

  6. Pressure dependence of magnetic ordering temperatures of rare earth - Sn/sub 3/ compounds

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, L E [Virginia Univ., Charlottesville (USA). Dept. of Physics; Guertin, R P; Foner, S

    1979-12-01

    Measurements of the hydrostatic pressure dependence of the Neel temperatures, Tsub(N), are reported for PrSn/sub 3/, NdSn/sub 3/, GdSn/sub 3/ and CeIn/sub 3/. Tsub(N) is found to increase with applied pressure for PrSn/sub 3/ and NdSn/sub 3/, whereas Tsub(N) is pressure independent within experimental error for GdSn/sub 3/ and CeIn/sub 3/. Slightly Sn-deficient RESn/sub 3/ (RE=rare earth) compounds are found consistently to be weakly ferromagnetic. The physical properties of the RESn/sub 3/ compounds exhibit analogies with the corresponding properties of dilute superconducting (LaRE)Sn/sub 3/ alloys. The high pressure data for PrSn/sub 3/ and CeIn/sub 3/ are qualitatively consistent with a 'Kondo necklace' model for magnetically ordered RE compounds with unstable 4f shells.

  7. First-principles study of magnetic properties of stoichiometric and O deficient low-index surfaces of rutile SnO{sub 2} and TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Han, Ruilin; Yang, Hui [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Department of Physics, Jilin University, Changchun 130012 (China); Wang, Dingdi [Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Du, Xiaobo [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Department of Physics, Jilin University, Changchun 130012 (China); Yan, Yu, E-mail: yanyu@jlu.edu.cn [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Department of Physics, Jilin University, Changchun 130012 (China)

    2015-01-15

    In consideration of experimental evidences of O vacancies or/and surface state as the possible origin of d{sup 0} ferromagnetism in SnO{sub 2} and TiO{sub 2}, the electronic structure and magnetic properties of stoichiometric and O deficient (110), (100), (101) and (001) surfaces of rutile SnO{sub 2} and TiO{sub 2} are investigated using first-principles calculations. The calculations show that the stoichiometric (110), (100), (101) and (001) surfaces of rutile SnO{sub 2} and TiO{sub 2} are nonmagnetic. The O vacancy at these low-index surfaces of SnO{sub 2} do not induce magnetic moment due to extended character of 5s and 5p orbitals of the reduced Sn atom, while the vacancy at the low-index surfaces of TiO{sub 2} produce spin splitting defect states in the band gap, resulting in the formation of magnetic moment of 2.0 μ{sub B}. The induced magnetic moment by surface O vacancy is mainly contributed by partially filled 3d orbitals of the reduced Ti atoms. It is noticed that the magnetic coupling between magnetic moments induced by two O vacancies at the low-index surfaces of rutile TiO{sub 2} are long-range ferromagnetic, which can be explained by the overlap of spin density around the common Ti or O atoms among reduced Ti atoms produced by two O vacancies. - Highlights: • Surface O vacancy does not induce magnetic moment in SnO{sub 2}. • Coupling between the moments induced by O vacancies at surfaces of TiO{sub 2} is ferromagnetic. • d{sup 0} ferromagnetism of TiO{sub 2} can be attributed to surface O vacancy.

  8. Study on the cause of iron-deficiency anemia in adolescent athletes by INAA with enriched stable isotopes

    International Nuclear Information System (INIS)

    Qian, Q.F.; Wu, S.Q.; Tian, J.B.; Huo, Z.P.; Chen, J.D.; Li, K.J.

    1991-01-01

    Iron deficiency anemia is still one of the most common nutritional deficiency diseases throughout the world. The incidence of iron deficiency is high especially in children, adolescent, and endurance athletes. The authors studied the iron absorption rate and iron balance in six child football players during training and non-training periods. The neutron activation method with enriched stable isotope 58Fe has been adopted. The results show that the rate of iron absorption in athletes during the training period (9.1 + 2.9%) was significantly lower than that during the non-training period (11.9 + 4.7%); the iron balance was negative and the sweat iron loss increased during training. Hair is one of the metabolism excretory organs. The physiological changes of body would influence the trace element contents in hair. The hairs collected from four athletes were measured by Synchrotron-induced X-ray Fluorescence analysis, so as to get the trace element contents. Preliminary results show that the changes of iron content in the hairs are in accordance with the athlete's physical activity. There are no perceptible changes for Zn and Ca. It is verified that exercise is one of the causes of iron deficiency in athletes. It is necessary to increase iron supply in an athletes' nutritional intake to ensure optimal performance ability

  9. Recent results on neutron rich tin isotopes by laser spectroscopy

    CERN Document Server

    Roussière, B; Crawford, J E; Essabaa, S; Fedosseev, V; Geithner, W; Genevey, J; Girod, M; Huber, G; Horn, R; Kappertz, S; Lassen, J; Le Blanc, F; Lee, J K P; Le Scornet, G; Lettry, Jacques; Mishin, V I; Neugart, R; Obert, J; Oms, J; Ouchrif, A; Peru, S; Pinard, J; Ravn, H L; Sauvage, J; Verney, D

    2001-01-01

    Laser spectroscopy measurements have been performed on neutron rich tin isotopes using the COMPLIS experimental setup. The nuclear charge radii of the even-even isotopes from A=108 to 132 are compared to the results of macroscopic and microscopic calculations. The improvements and optimizations needed to perform the isotope shift measurement on $^{134}$Sn are presented.

  10. Study of neutron deficient iridium isotopes by using laser spectroscopy; Etude des noyaux d'iridium deficients en neutrons par spectroscopie laser

    Energy Technology Data Exchange (ETDEWEB)

    Verney, D

    2000-12-19

    Resonance ionization spectroscopy was performed on neutron deficient iridium isotopes {sup 182-189}Ir, {sup 186}Ir{sup m} and stable isotopes {sup 191,193}Ir. Hyperfine spectra were recorded from the optical transition at 351,7 nm between the 5d{sup 7}6s{sup 2} {sup 4}F{sub 9/2} ground state and the 5d{sup 7}6s6p {sup 6}F{sub 11/2} excited state. Radioactive iridium isotopes were obtained from {beta}{sup +}/EC decay of radioactive mercury nuclei deposited on a graphite substrate. The radioactive mercury nuclei were produced at the ISOLDE facility at CERN through spallation reactions, by bombarding a molten lead target with the 1 GeV proton beam delivered by the PS-Booster. Magnetic dipole moments and spectroscopic quadrupole moments were extracted from the hyperfine spectra. The mean square charge radius variations, as deduced from the measured isotopic shift, show a sharp change between {sup 187}Ir and {sup 186}Ir{sup g}, accompanied by a sudden increase in deformation: from {beta}2 {approx} 0,16 to {beta}2 > 0, 2. These results were analysed in the framework of an axial rotor plus one or two quasiparticles. The wave functions of the osmium and platinum cores which are used in order to describe the iridium nuclei were calculated from the HF+BCS method with the Skyrme SIII effective interaction. The cores were constrained to take the deformation parameters extracted from the isotopic shift measurements. One shows then that this sudden deformation change corresponds also to a change in the proton state that describes the odd nuclei ground state or that participates in the coupling with the neutron in odd-odd nuclei. This state is identified with the {pi}3/2{sup +}[402] orbital for the smaller deformations nuclei and with the {pi}1/2{sup -}[541] orbital stemming from the h{sub 9/2} subshell for bigger deformations nuclei. (author)

  11. High-spin studies and nuclear structure in three semi-magic regions of the chart: High-seniority states in Sn isotopes

    International Nuclear Information System (INIS)

    Astier, A.

    2013-01-01

    Two fusion-fission experiments have been performed and studied with the Euroball Ge array: 12 C+ 238 U at 90 MeV bombarding energy, and 18 O + 208 Pb at 85 MeV. Among the lot of new information extracted during the last decade, the latest results discussed here are the discovery of the high-spin states of 119-126 Sn. The maximum value of angular momentum available in the Vh 11/2 shell, i.e. for mid-occupation and the breaking of the three neutron pairs (seniority v = 6), has been identified in several tin isotopes. It is the first time that such high-seniority states are established in spherical nuclei. (authors)

  12. Nuclear reactions of neutron-rich Sn isotopes investigated at relativistic energies at R{sup 3}B

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Fabia; Aumann, Thomas; Horvat, Andrea [TU Darmstadt (Germany); Boretzky, Konstanze [GSI Helmholtzzentrum (Germany); Schrock, Philipp [CNS, University of Tokyo (Japan); Johansen, Jacob [Aarhus University (Denmark); Collaboration: R3B-Collaboration

    2016-07-01

    Nuclei with a large neutron excess are expected to form a neutron-rich surface layer which is often referred to as the neutron skin. The investigation of this phenomenon is of great interest in nuclear-structure physics and offers a possibility to constrain the equation-of-state of neutron-rich matter. Assuming a geometrical description of reaction processes as in the eikonal approximation, nuclear-induced reactions are a good tool to probe the neutron skin. Measured reaction cross sections can be used to constrain the density distributions of protons and neutrons in the nucleus and therefore the neutron-skin thickness. For this purpose, reactions of neutron-rich tin isotopes in the A=124-134 mass range have been measured on a carbon target at the R{sup 3}B-setup at GSI in inverse kinematics in a kinematically complete manner. Preliminary results for the reaction cross sections of {sup 124}Sn are presented.

  13. Phase separation and antisite defects in the thermoelectric TiNiSn half-Heusler alloys

    International Nuclear Information System (INIS)

    Kirievsky, K.; Gelbstein, Y.; Fuks, D.

    2013-01-01

    The half-Heusler TiNiSn alloys have recently gained an attention as promising candidates for thermoelectric applications. Improvement of these alloys for such applications can be obtained by both electronic and compositional optimizations. The latter can result in a miscibility gap, allowing a phase separation in the nano-scale and consequently a thermal conductivity reduction. Combination of ab initio calculations and statistical thermodynamics was applied for studying the relative stability of a number of superstructures in TiNiSn based alloys. The quasi-binary phase diagram beyond T=0 K for TiNiSn–TiNi 2 Sn solid solutions was calculated using energy parameters extracted from the total energy calculations for ordered structures in the Ni sublattice. We demonstrated that a decomposition of the off-stoichiometric Ni-rich half-Heusler alloy into the stoichiometric TiNiSn phase and into Ni deficient Heusler TiNi 2 Sn phase occurs at elevated temperatures—an effect which recently had been observed experimentally. Furthermore, favorable energetic conditions for antisite defects formation were deduced, based on calculations of the energy of formation, an effect which was explained as a cooperative process of partial disordering on the Ni sublattice. The influence of these two effects on improvement of the thermoelectric performance of TiNiSn based half Heusler compounds is discussed. - Graphical abstract: Phase separation and antisite defects in the thermoelectric TiNiSn alloy, are covered as methods for nanostructuring and thereby enhancement of the thermoelectric potential. - Highlights: • Ab initio calculations/statistical thermodynamics was applied for studying the TiNiSn system. • The phase diagram for TiNiSn–TiNi 2 Sn solid solutions was calculated. • Decomposition of the Ni-rich HH into TiNiSn and Ni deficient TiNi 2 Sn phases was observed. • Favorable energetic conditions for antisite defects formation were deduced

  14. Search for EC-decayed neutron-deficient actinide isotopes using gas-jet coupled JAERI-ISOL

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, Kazuaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    To study the nuclear properties of unknown neutron deficient actinide isotopes which decay mainly via orbital electron capture (EC), we have developed a composite system consisting of a gas-jet transport apparatus and a thermal ion-source at the JAERI-ISOL. With this system, search for {sup 236}Am produced in the {sup 235}U({sup 6}Li, 5n) reaction has been performed. Pu KX-rays associated with the EC decay of {sup 236}Am are observed at the mass-236 fraction. The half-life of {sup 236}Am is evaluated to be 4.4min. The outline of the gas-jet coupled JAERI-ISOL system and typical performance are given. (author)

  15. Magmatic nature of Sn-bearing fluids from isotopic (H,O) data of tourmalines (Solnechnoye deposit, Far East of Russia)

    Science.gov (United States)

    Sushchevskaya, Tatiana; Ignatiev, Alexander; Velivetskaya, Tatiana

    2010-05-01

    It was shown, that the main factors, controlled Sn-W ore deposition in hydrothermal systems in connection with granites were: a) cooling, b) mixing of fluids of different composition and genesis, c) heterogenization (boiling) of mineral forming fluids (Heinrich, 1990; et al). The results of physical chemical modelling of water-rock interaction pointed to magmatic nature of tin-bearing fluids in the hydrothermal systems, connected with granites. Tin concentration in model magmatogeneous fluid was calculated to be three times higher than in the model exogenic fluid (Sushchevskaya, Ryzhenko, 1998). New data on the source of ore forming fluids, which had formed the large economic Solnechnoye Sn deposit (Far East of Russia), were obtained from hydrogen and oxygen isotopic composition of tourmalines from successive mineral associations. Hydrogen position in the tourmaline crystal structure allows to suppose, that postproductive processes did not change the initial δD values, in contrast to phyllosilicates, often used for this purpose. During mineral formation at the Solnechnoye deposit tourmaline was formed practically without interruption. Its composition was gradually changed from schorl to dravite, when temperature decreased. The ores of cassiterite-tourmaline type were formed in a vertically dipping fracture zones, extended in a metamorphosed sandstone-shale rocks. Hydrogene and oxygen isotopic composition of fluids were calculated from tourmaline data with the help of equations, proposed in (Kotzer et al., 1993). The temperature intervals for these calculations were accepted as: 1- 450-400o C for quartz-tourmaline preore stage, 2 - 400-350o C -for early productive quartz-cassiterite stage, 3 - 350-300o C - for late quartz- cassiterite stage. The obtained results corresponded to magmatic character of the fluids of productive stage of the Solnechnoye deposit, because their isotopic composition lied in the interval: δ18О (3.2-9.3)‰, δD -(31.7-76.6)‰. The

  16. A 20MeV (p,d) study of nuclear structure in the even and odd tin isotopes

    International Nuclear Information System (INIS)

    Fleming, D.G.; Paris-11 Univ., 91 - Orsay

    1978-01-01

    The even and odd tin isotopes have been studied by 20 MeV (p,d) reactions. States strongly populated in the odd isotopes are due to the valence neutron shells and extend up to only 2 MeV of excitation energy; 'deep hole' states were not identified. The occupation probabilities extracted from finite-range distorted-wave-Born-approximation calculations generally agree well with the predictions of the BCS theory of superconducting nuclei, particularly with the calculations of Clement and Baranger. In the even tin isotopes, strongly populated states are characterized predominantly by L=2 transfers extending up to 4 MeV excitation energy. The experimental spectroscopic factors are compared with the BCS calculated values of Clement and Baranger, Alzetta and Sawicki, and Van Gunsteren; relatively good agreement is obtained for L=2 transitions, but not for L=0 transitions. A considerable fraction of the sum rule L=2 strength in 118 Sn is missing in the 119 Sn(p,d) 118 Sn experimental spectrum; in like manner, no 4 + strength could be identified in either 114 Sn or 118 Sn

  17. The RELixSn2 (RE=La–Nd, Sm, and Gd; 0≤x<1) series revisited. Synthesis, crystal chemistry, and magnetic susceptibilities

    International Nuclear Information System (INIS)

    Makongo, Julien P.A.; Suen, Nian-Tzu; Guo, Shengping; Saha, Shanta; Greene, Richard; Paglione, Johnpierre; Bobev, Svilen

    2014-01-01

    This study is concerned with the ternary compounds RELi x Sn 2 (RE=La–Nd, Sm, and Gd; 0≤x 2 phases. These materials crystallize with the base-centered orthorhombic space group Cmcm (No. 63), and can be formally assigned with the CeNiSi 2 structure type (Pearson symbol oC16). Our systematic single-crystal X-ray diffraction studies revealed substantial Li-deficiencies in all cases, with SmSn 2 (space group Cmmm, ZrGa 2 structure type, Pearson symbol oC12) and GdSn 2 (space group Cmcm, ZrSi 2 structure type, Pearson symbol oC12) being completely lithium-free. The structure refinements also uncovered positional disorder on the Sn site neighboring the vacancies. The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 and GdSn 2 structures are devoid of any disorder. Temperature-dependent studies of the magnetic response of the title compounds are also presented and discussed. -- Graphical abstract: RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type (a). The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 (b) and GdSn 2 (c) structures are devoid of any disorder. Highlights: • The crystal structures of the RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type or defect variant of the CeNiSi 2 structure type. • SmSn 2 is isotypic with the ZrGa 2 structure, while RESn 2 (RE=Gd–Lu) are isotypic with the ZrSi 2 structure

  18. Investigation of the (p,p'), (p,d) and (p,t) reactions on some light Sn isotopes

    International Nuclear Information System (INIS)

    Blankert, P.J.

    1979-01-01

    The results are presented of the 112 Sn(p,p') 112 Sn reaction. Apart from the usual distorted-wave analysis the excitation of some states is described in the coupled-channels formalism. The results of the 112 Sn(p,d) 111 Sn and the 112 Sn(p,t) 110 Sn reactions are also reported. From the (p,d) reaction quasi-particle energies and occupation numbers are determined. Two-step DWBA calculations are performed for some states that are assumed to result from the coupling of a quasiparticle to the 2 + 1 or 3 - 1 state of the even core. In the gross structure above 3 MeV of excitation, pickup strength from deeply-bound hole states is observed. The (p,t) reaction provided spin and parity of a number of levels in 110 Sn. A two-step DWBA analysis of the excitation of the ground state and first excited 2 + state shows the importance of second-order processes. The combined results of the (p,t) reactions on 112 Sn, 114 Sn and 116 Sn are given with some emphasis on the systematic features. The derivation is given of some expressions for spectroscopic amplitudes necessary in the two-step DWBA calculations for the (p,t) reactions. For all reactions a comparison is made with other existing data and with the results of model calculations. (Auth.)

  19. Elastic and inelastic {alpha}-scattering cross-sections obtained with the 44 MeV fixed energy Saclay cyclotron on separated targets of {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 40}Ca, {sup 46}Ti, {sup 48}Ti, {sup 50}Ti, {sup 52}Cr, {sup 54}Fe, {sup 56}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 112}Sn, {sup 114}Sn, {sup 116}Sn, {sup 118}Sn, {sup 120}Sn, {sup 122}Sn, {sup 124}Sn and {sup 208}Pb using the Saclay fixed-energy cyclotron; Sections efficaces differentielles elastiques et inelastiques obtenues par diffusion de particules {alpha} de 44 MeV sur des cibles de {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 40}Ca, {sup 46}Ti, {sup 48}Ti, {sup 50}Ti, {sup 52}Cr, {sup 54}Fe, {sup 56}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 112}Sn, {sup 114}Sn, {sup 116}Sn, {sup 118}Sn, {sup 120}Sn, {sup 122}Sn, {sup 124}Sn et {sup 208}Pb au cyclotron a energie fixe de saclay

    Energy Technology Data Exchange (ETDEWEB)

    Bruge, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physique nucleaire, service de physique nucleaire a moyenne energie

    1967-01-01

    This report contains elastic and inelastic {alpha}-scattering cross-sections obtained with the 44 MeV fixed energy Saclay cyclotron on Mg, Ca, Ti, Cr, Fe, Ni, Co, Zn, Sn and Pb enriched targets. (author) [French] Ce rapport contient les tableaux des sections efficaces differentielles obtenues par diffusion elastique et inelastique des particules {alpha} de 44 MeV, fournies par le cyclotron a energie fixe de Saclay, sur des cibles d'isotopes separes de Mg, Ca, Ti, Cr, Fe, Ni, Co, Zn, Sn et Pb. (auteur)

  20. The statistical properties of 111,112,113Sn studied with the Oslo method

    Science.gov (United States)

    Tveten, G. M.; Bello Garrote, F. L.; Campo, L. C.; Eriksen, T. K.; Giacoppo, F.; Guttormsen, M.; Görgen, A.; Hagen, T. W.; Hadynska-Klek, K.; Klintefjord, M.; Larsen, A. C.; Maharromova, S.; Nyhus, H. T.; Renstrøm, T.; Rose, S.; Sahin, E.; Siem, S.; Tornyi, T. G.

    2015-05-01

    The γ-ray strength function and level density of 111, 112, 113Sn are being studied at the Oslo Cyclotron Laboratory (OCL) up to the neutron binding energy by applying the Oslo method to particle-γ coincidence data. The preliminary results for the γ-ray strength function are discussed in the context of the results for the more neutron-rich Sn-isotopes previously studied at OCL.

  1. The statistical properties of 111,112,113Sn studied with the Oslo method

    Directory of Open Access Journals (Sweden)

    Tveten G. M.

    2015-01-01

    Full Text Available The γ-ray strength function and level density of 111, 112, 113Sn are being studied at the Oslo Cyclotron Laboratory (OCL up to the neutron binding energy by applying the Oslo method to particle-γ coincidence data. The preliminary results for the γ-ray strength function are discussed in the context of the results for the more neutron-rich Sn-isotopes previously studied at OCL.

  2. $\\gamma$- spectroscopy of n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li: Introduction to HIE-ISOLDE studies of n-rich Sb and Tl isotopes with Sn and Hg radioactive beams.

    CERN Document Server

    Fornal, B; Bednarczyk, P; Cieplicka, N; Krolas, W; Maj, A; Leoni, S; Benzoni, G; Blasi, N; Bottoni, S; Bracco, A; Camera, F; Crespi, F; Million, B; Morales, A; Wieland, O; Rusek, K; Lunardi, S; Mengoni, D; Recchia, F; Ur, CA; Valiente-Dobon, J; de France, G; Clement, E; Elseviers, J; Flavigny, F; Huyse, M; Raabe, R; Sambi, S; Van Duppen, P; Sferrazza, M; Simpson, G; Georgiev, G; Sotty, C; Blazhev, A; German, R; Siebeck, B; Seidlitz, M; Reiter, P; Warr, N; Boenig, S; Ilieva, S; Kroell, T; Scheck, M; Thurauf, M; Gernhaeuser, R; Mucher, D; Janssens, R; Carpenter, MP; Zhu, S; Marginean, NM; Balabanski, D; Kowalska, M

    2012-01-01

    $\\gamma$- spectroscopy of n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li: Introduction to HIE-ISOLDE studies of n-rich Sb and Tl isotopes with Sn and Hg radioactive beams.

  3. Coulomb excitation of neutron-deficient polonium isotopes studied at ISOLDE

    CERN Document Server

    Neven, Michiel

    The polonium isotopes represent an interesting region of the nuclear chart having only two protons outside the Z = 82 closed shell. These isotopes have already been extensively studied theoretically and experimentally. The heavier isotopes (A > 200) seem to follow a "regular seniority-type regime" while for the lighter isotopes (A < 200) a more collective behavior is observed. Many questions remain regarding the transition between these two regimes and the configuration mixing between quantum states. Experiments in the lighter polonium isotopes point to the presence of shape coexistence, however the phenomenon is not fully understood. A Coulomb excitation study of the polonium isotopes whereby the dynamic properties are investigated can provide helpful insights in understanding the shape coexistence phenomena. In this thesis $^{202}$Po was studied via Coulomb excitation. The $^{202}$Po isotope was part of an experimental campaign in which the $^{196,198,200,206}$Po isotopes were studied as well via Coulomb...

  4. Sup(110)Sn/110In - a new generator system for positron emission tomography

    International Nuclear Information System (INIS)

    Lundqvist, H.; Einarsson, L.; Malmborg, P.; Scott-Robson, S.

    1991-01-01

    A generator system, 110 Sn/ 110 In, is suggested for use in the labelling of leukocytes with this short-lived (t 1/2 = 1.15 h) positron emitting (62%) isotope of indium. The half-life gives the labelled leukocytes time to be adequately distributed but is short enough to allow repeated studies within a few hours. The mother radionuclide 110 Sn (t 1/2 = 4.15 h) is produced by the reaction nat In(p, xn) 110 Sn which has a maximum cross-section of 110 mb at approx. 70 MeV and a practical yield of 400 MBq/μAh. (author)

  5. SnRK1 activates autophagy via the TOR signaling pathway in Arabidopsis thaliana.

    Science.gov (United States)

    Soto-Burgos, Junmarie; Bassham, Diane C

    2017-01-01

    Autophagy is a degradation process in which cells break down and recycle their cytoplasmic contents when subjected to environmental stress or during cellular remodeling. The Arabidopsis thaliana SnRK1 complex is a protein kinase that senses changes in energy levels and triggers downstream responses to enable survival. Its mammalian ortholog, AMPK, and yeast ortholog, Snf-1, activate autophagy in response to low energy conditions. We therefore hypothesized that SnRK1 may play a role in the regulation of autophagy in response to nutrient or energy deficiency in Arabidopsis. To test this hypothesis, we determined the effect of overexpression or knockout of the SnRK1 catalytic subunit KIN10 on autophagy activation by abiotic stresses, including nutrient deficiency, salt, osmotic, oxidative, and ER stress. While wild-type plants had low basal autophagy activity in control conditions, KIN10 overexpression lines had increased autophagy under these conditions, indicating activation of autophagy by SnRK1. A kin10 mutant had a basal level of autophagy under control conditions similar to wild-type plants, but activation of autophagy by most abiotic stresses was blocked, indicating that SnRK1 is required for autophagy induction by a wide variety of stress conditions. In mammals, TOR is a negative regulator of autophagy, and AMPK acts to activate autophagy both upstream of TOR, by inhibiting its activity, and in a parallel pathway. Inhibition of Arabidopsis TOR leads to activation of autophagy; inhibition of SnRK1 did not block this activation. Furthermore, an increase in SnRK1 activity was unable to induce autophagy when TOR was also activated. These results demonstrate that SnRK1 acts upstream of TOR in the activation of autophagy in Arabidopsis.

  6. Anomalous behavior of 2+ excitations around 132Sn

    International Nuclear Information System (INIS)

    Terasaki, J.; Engel, J.; Nazarewicz, W.; Stoitsov, M.

    2002-01-01

    In certain neutron-rich Te isotopes, a decrease in the energy of the first excited 2 + state is accompanied by a decrease in the E2 strength to that state from the ground state, contradicting simple systematics and general intuition about quadrupole collectivity. We use a separable quadrupole-plus-pairing Hamiltonian and the quasiparticle random phase approximation to calculate energies, B(E2,0 + →2 + ) strengths, and g factors for the lowest 2 + states near 132 Sn (Z≥50). We trace the anomalous behavior in the Te isotopes to a reduced neutron pairing above the N=82 magic gap

  7. Identification of excited states in 167Os and 168Os: shape coexistence at extreme neutron deficiency

    International Nuclear Information System (INIS)

    Joss, D.T.; King, S.L.; Page, R.D.; Simpson, J.; Keenan, A.; Amzal, N.; Baeck, T.; Bentley, M.A.; Cederwall, B.; Cocks, J.F.C.; Cullen, D.M.; Greenlees, P.T.; Helariutta, K.; Jones, P.M.; Julin, R.; Juutinen, S.; Kankaanpaeae, H.; Kettunen, H.; Kuusiniemi, P.; Leino, M.; Muikku, M.; Savelius, A.; Uusitalo, J.; Williams, S.J.

    2001-01-01

    Excited states in the very neutron-deficient isotopes 167 Os and 168 Os have been observed using the reaction 112 Sn( 58 Ni, 2pxn). The JUROSPHERE γ-ray spectrometer array was used in conjunction with the RITU gas-filled recoil separator to collect prompt γ radiation in coincidence with recoils implanted in a silicon strip detector located at the focal plane of RITU. Using a selective recoil decay tagging technique it has been possible to unambiguously assign γ-ray transitions to 167 Os and 168 Os through the characteristic α radioactivity of these nuclides. The high-spin structure of the bands is discussed in terms of quasiparticle configurations within the framework of the cranked shell model. The role of shape coexistence in 168 Os is examined with phenomenological three-band mixing calculations

  8. Decay studies of new neutron deficient isotopes in the range of elements between gadolinium and lead

    CERN Document Server

    Hofmann, S; Faust, W; Guttner, K; Hessberger, F P; Münzenberg, G; Reisdorf, W; Schneider, J H R; Thuma, B

    1981-01-01

    Very neutron deficient isotopes below lead are produced with beams of /sup 58/Ni, /sup 92/Mo, and /sup 107/Ag accelerated by the linear accelerator UNILAC. After separation from the projectile beam by the velocity filter SHIP, the fusion products are implanted with their full recoil energy into an array of position-sensitive detectors. With a newly developed position and time correlation technique, parent daughter relationships, half lives and alpha branching ratios of a large number of isotopes are determined. Two new alpha emitting isomeric states are identified in /sup 155/Lu and /sup 156/Hf. The energies of the excited states are (1798+or-12) keV in /sup 155/Lu and (1977+18) keV in /sup 156/Hf, the half-lives are (2.60+or-0.07) ms and (444+or-17) mu s, respectively. Compared to the ground state transitions, a hindrance of 10/sup 5/ can be deduced for both transitions, possibly indicating orbital angular momenta of the order of 10 h(cross) for the alpha emitting states. The isomers are proposed to belong t...

  9. Contrasting Cu-Au and Sn-W Granite Metallogeny through the Zircon Geochemical and Isotopic Record

    Science.gov (United States)

    Gardiner, Nicholas; Hawkesworth, Chris; Robb, Laurence; Whitehouse, Martin; Roberts, Nick; Kirkland, Chris

    2017-04-01

    Magmatic genesis and evolution - mediated by geodynamic setting - exert a primary control on the propensity of granites to be metal fertile. A revolution in our understanding of these petrogenetic processes has been made through a range of mineral-based tools, most notably the common accessory mineral zircon. There is consequently considerable interest in whether the geochemical and isotopic compositions of zircon can be applied to metallogenic problems. The paired magmatic belts of Myanmar have broadly contrasting metallogenic affinities (Sn-W versus Cu-Au), and are interpreted to have formed on the accretionary margin of the subducting Neo-Tethys Ocean. They therefore present the opportunity to geochemically compare and contrast the zircon compositions in two end-member types of granite-hosted mineral deposits generated in collisional settings. We present an integrated zircon isotope (U-Pb, Lu-Hf, O) and trace element dataset that fingerprint: (a) source; (b) redox conditions; and (c) degree of fractionation. These variables all impact on magma fertility, and our key question to address is whether they can be reliably traced and calibrated within the Myanmar zircon record. Granitoid-hosted zircons from the I-type copper arc have juvenile ɛHf (+7 to +12) and mantle-like δ18O (5.3 ‰), whereas zircons from the S-type tin belt have low ɛHf (-7 to -13) and heavier δ18O (6.2-7.7 ‰). Plotting Hf versus U/Yb reaffirms that the tin belt magmas contain greater crustal contributions than the copper arc rocks. Links between whole rock Rb/Sr and zircon Eu/Eu* highlights that the latter can be used to monitor magma fractionation in systems that crystallize plagioclase (low Sr/Y). Ce/Ce* and Eu/Eu* in zircon are thus sensitive to redox and fractionation respectively, and can be used to evaluate the sensitivity of zircons to the metallogenic affinity of their host rocks. Tin contents that exceed the solubility limit are required in order to make a magmatic

  10. Fragmentation of neutron hole states in /sup 111,115/Sn

    International Nuclear Information System (INIS)

    Vdovin, A.I.; Thao, N.D.; Solov'ev, V.G.; Stoyanov, C.

    1983-01-01

    The quasiparticle-phonon model of the nucleus with inclusion of the interaction of one-quasiparticle states with a large number of states of the quasiparticle + phonon and quasiparticle + two phonons type is used to calculate the fragmentation of the deep hole subshells 2p/sub 1/2/, 2p/sub 3/2/, 1f/sub 5/2/, and others in the isotopes /sup 111,115/Sn. Satisfactory agreement is obtained with the results of recent (d,t) experiments in the even isotopes of tin

  11. Investigation of low-lying dipole strength in {sup 124}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Symochko, D.; Aumann, T.; Duchene, M.; Knoerzer, M.; Pietralla, N.; Scheit, H. [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); Bhike, M.; Kelley, J.; Tornow, W. [Department for Physics, Duke University (United States); Derya, V.; Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln (Germany); Isaak, J.; Loeher, B.; Savran, D. [ExtreMe Matter Institute EMMI and Research Division, Darmstadt (Germany); Tonchev, A. [Lawrence Livermore National Laboratory (United States); Werner, V. [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); WNSL, Yale University (United States)

    2014-07-01

    Dipole excitations in the semi-magic {sup 124}Sn nucleus were studied in (γ,γ') reactions using the γ{sup 3}-high-efficiency detector setup. The experiment was carried out with quasimonoenergetic photon beams provided by the HIγS facility at the TUNL in the energy range from 5.2 to 8.6 MeV at 15 different energies. Measurements allowed to identify near 80 new transitions to the ground state, obtain reduced transition probabilities and assign parity quantum numbers to the observed excited states. Besides, the γ-γ coincidence technique gave access to the γ-decay pattern of the Pygmy Dipole Resonance, e.g. it was possible to analyse the branching ratios to the first excited 2{sup +} state. Investigations were made as a part of the experimental campaign aimed to obtain a complete picture of dipole strength function evolution in Sn isotopes - from stable {sup 112}Sn to short-lived {sup 134}Sn.

  12. Synthesis and characterization of different morphological SnS nanomaterials

    International Nuclear Information System (INIS)

    Chaki, Sunil H; Chaudhary, Mahesh D; Deshpande, M P

    2014-01-01

    SnS in three nano forms possessing different morphologies such as particles, whiskers and ribbons were synthesised by chemical route. The morphology variation was brought about in the chemical route synthesis by varying a synthesis parameter such as temperature and influencing the synthesis by use of surfactant. The elemental composition determination by energy dispersive analysis of x-rays (EDAX) showed that all three synthesized SnS nanomaterials were tin deficient. The x-ray diffraction (XRD) study of the three SnS nanomaterials showed that all of them possess orthorhombic structure. The Raman spectra of the three SnS nanomaterials showed that all three samples possess three common distinguishable peaks. In them two peaks lying at 98 ± 1 cm −1 and 224 ± 4 cm −1 are the characteristic A g mode of SnS. The third peak lying at 302 ± 1 cm −1 is associated with secondary Sn 2 S 3 phase. The transmission electron microscopy (TEM) confirmed the respective morphologies. The optical analysis showed that they possess direct as well as indirect optical bandgap. The electrical transport properties study on the pellets prepared from the different nanomaterials of SnS showed them to be semiconducting and p-type in nature. The current–voltage (I–V) plots of the silver (Ag)/SnS nanomaterials pellets for dark and incandescent illumination showed that all configurations showed good ohmic behaviour except Ag/SnS nanoribbons pellet configuration under illumination. All the obtained results are discussed in detail. (paper)

  13. Stable isotope studies of the Glen Eden Mo-W-Sn deposit, New England Batholith - Australia

    International Nuclear Information System (INIS)

    Somarin, A.K.

    2000-01-01

    The Glen Eden Mo-W-Sn deposit is located 17 km northeast of Glen Innes in northeastern New South Wales. This deposit is located in the Late-Permian Emmaville Volcanics and mineralisation is related to the intrusion of the Glen Eden Granite (GEG). Glen Eden Granite is a highly-fractionated, most probably, I-type granite and it occurs as dykes at depths of more than 80 m and is not exposed at the surface. Mineralogical studies and field evidence indicate that the observed dykes have intruded after initiation of the hydrothermal activity. The Glen Eden orebody is composed of a pipe-like breccia body, veins and stockworks including moderately to steeply dipping, mainly NW- and NE- striking ore-bearing veinlets. Also, there are some ores in altered felsic volcanic wall rock, especially the greisen zone. The ore minerals include molybdenite, wolframite, cassiterite, Bi-bearing minerals and base metal sulfides. Two main mineralisation stages can be recognised: 1) before main brecciation (pre-breccia stage). 2) after main brecciation (post-breccia stage). The isotopic composition of the hydrothermal fluid at the pre-breccia stage is different from that at the post-breccia stage (see below). The main stage of ore mineralisation, based on fluid inclusion studies, has occurred at 280 to 360 deg C. Hydrothermal alteration at Glen Eden is similar to porphyry-type ore deposits and has been developed largely in the felsic volcanic host rocks. However, sericitic alteration has developed pervasively and formed the greisen zone. Various alteration styles include biotitic, greisen, potassic, argillic and propylitic types. Muscovite from greisen has given an early Triassic age of 240 Ma (Plimer,l.R., pers. comm., 2000). This paper summaries the stable isotope studies of this deposit

  14. Enhanced thermoelectric property of oxygen deficient nickel doped SnO2 for high temperature application

    Science.gov (United States)

    Paulson, Anju; Sabeer, N. A. Muhammad; Pradyumnan, P. P.

    2018-04-01

    Motivated by the detailed investigation on the thermoelectric performance of oxide materials our work concentrated on the influence of acceptor dopants and defect density in the lattice plane for the enhancement of thermoelectric power. The series of Sn1‑x Nix O2 (0.01 ≤ x ≤ 0.05) compositions were prepared by solid state reaction mechanism and found that 3 atomic percentage Ni doped SnO2 can be considered as a good candidate due to its promising electrical and transport properties. Defect lattices were introduced in the sample and the deviation from oxygen stochiometry was ensured using photoluminescence measurement. High power factor was obtained for the 3 atomic percentage nickel doped SnO2 due to the effective number of charge carrier concentration and the depletion of oxygen rich layers. Defect centered and acceptor doped SnO2 lattice opens a new door for energy harvesting at higher temperatures.

  15. Whisker and Hillock formation on Sn, Sn-Cu and Sn-Pb electrodeposits

    International Nuclear Information System (INIS)

    Boettinger, W.J.; Johnson, C.E.; Bendersky, L.A.; Moon, K.-W.; Williams, M.E.; Stafford, G.R.

    2005-01-01

    High purity bright Sn, Sn-Cu and Sn-Pb layers, 3, 7 and 16 μm thick were electrodeposited on phosphor bronze cantilever beams in a rotating disk apparatus. Beam deflection measurements within 15 min of plating proved that all electrodeposits had in-plane compressive stress. In several days, the surfaces of the Sn-Cu deposits, which have the highest compressive stress, develop 50 μm contorted hillocks and 200 μm whiskers, pure Sn deposits develop 20 μm compact conical hillocks, and Sn-Pb deposits, which have the lowest compressive stress, remain unchanged. The differences between the initial compressive stresses for each alloy and pure Sn is due to the rapid precipitation of Cu 6 Sn 5 or Pb particles, respectively, within supersaturated Sn grains produced by electrodeposition. Over longer time, analysis of beam deflection measurements indicates that the compressive stress is augmented by the formation of Cu 6 Sn 5 on the bronze/Sn interface, while creep of the electrodeposit tends to decrease the compressive stress. Uniform creep occurs for Sn-Pb because it has an equi-axed grain structure. Localized creep in the form of hillocks and whiskers occurs for Sn and Sn-Cu because both have columnar structures. Compact hillocks form for the Sn deposits because the columnar grain boundaries are mobile. Contorted hillocks and whiskers form for the Sn-Cu deposits because the columnar grain boundary motion is impeded

  16. Fragmentation of neutron hole states in the sup(111,115)Sn

    International Nuclear Information System (INIS)

    Vdovin, A.I.; Nguen Din' Tkhao; Solov'ev, V.G.; Stoyanov, Ch.

    1983-01-01

    In the framework of the quasiparticle-phonon nuclear model, taking into account an interaction of one-quasiparticle states with large number states of the (quasiparticle + phonon) and (quasiparticle + two phonons) type, the fragmentation is calculated for deep hole subshells 2psub(1/2), 2psub(3/2), 1fsub(5/2) and others in the isotopes sup(111,115)Sn. A satisfactory agreement with the results of recent experiments on the (d, t) reactions on even tin isotopes is obtained

  17. Direct Reaction Experimental Studies with Beams of Radioactive Tin Ions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K. L. [University of Tennessee, Knoxville (UTK); Ahn, S.H. [University of Tennessee, Knoxville (UTK); Allmond, James M [ORNL; Ayres, A. [University of Tennessee, Knoxville (UTK); Bardayan, Daniel W [ORNL; Baugher, T. [Michigan State University, East Lansing; Bazin, D. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL); Beene, James R [ORNL; Berryman, J. S. [Michigan State University, East Lansing; Bey, A. [University of Tennessee, Knoxville (UTK); Bingham, C. R. [University of Tennessee, Knoxville (UTK); Cartegni, L. [University of Tennessee, Knoxville (UTK); Chae, K. Y. [University of Tennessee, Knoxville (UTK)/Sungkyunkwan University, Korea; Cizewski, J. A. [Rutgers University; Gade, A. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL); Galindo-Uribarri, Alfredo {nmn} [ORNL; Garcia-Ruiz, R.F. [Instituut voor Kernen Stralingsfysica, KU Leuven, B-3001, Leuven, Belgium; Grzywacz, Robert Kazimierz [ORNL; Howard, Meredith E [ORNL; Kozub, R. L. [Tennessee Technological University (TTU); Liang, J Felix [ORNL; Manning, Brett M [ORNL; Matos, M. [Louisiana State University; McDaniel, S. [Michigan State University, East Lansing; Miller, D. [University of Tennessee, Knoxville (UTK); Nesaraja, Caroline D [ORNL; O' Malley, Patrick [Rutgers University; Padgett, S [University of Tennessee, Knoxville (UTK); Padilla-Rodal, Elizabeth [Universidad Nacional Autonoma de Mexico (UNAM); Pain, Steven D [ORNL; Pittman, S. T. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Radford, David C [ORNL; Ratkiewicz, Andrew J [ORNL; Schmitt, Kyle [ORNL; Smith, Michael Scott [ORNL; Stracener, Daniel W [ORNL; Stroberg, S. [Michigan State University, East Lansing; Tostevin, Jeffrey A [ORNL; Varner Jr, Robert L [ORNL; Weisshaar, D. [Michigan State University, East Lansing; Wimmer, K. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL)/Central Michigan University; Winkler, R. [Michigan State University, East Lansing

    2015-01-01

    The tin chain of isotopes provides a unique region in which to investigate the evolution of single-particle structure, spreading from N = 50 at Sn-100, through 10 stable isotopes and the N = 82 shell closure at Sn-132 out into the r-process path. Direct reactions performed on radioactive ion beams are sensitive spectroscopic tools for studying exotic nuclei. Here we present one experiment knocking out neutrons from tin isotopes that are already neutron deficient and two reactions that add a neutron to neutron-rich Sn-130. Both techniques rely on selective particle identification and the measurement of gamma rays in coincidence with charged ions. We present the goals of the two experiments and the particle identification for the channels of interest. The final results will be presented in future publications.

  18. High-resolution neutron capture and transmission measurements and the stellar neutron capture cross sections of 116,120Sn

    International Nuclear Information System (INIS)

    Koehler, P.E.; Spencer, R.R.; Guber, K.H.

    1997-01-01

    Improved astrophysical reaction rates for 116,120 Sn(n, γ) are of interest because nucleosynthesis models have not been able to reproduce the observed abundances in this mass region. For example, previous s-process calculations have consistently underproduced the s-only isotope 116 Sn. Also, these studies have resulted in residual reprocess abundances for the tin isotopes which are systematically larger than predicted by reprocess calculations. It has been suggested that these problems could be solved by reducing the solar tin abundance by 10-20%, but there is no experimental evidence to justify this renormalization. Instead, it is possible that the problem lies in the (n,T) cross sections used in the reaction network calculations or in the s-process models. One reason to suspect the (n, γ) data is that previous measurements did not extend to low enough energies to determine accurately the Maxwellian-averaged capture cross sections at the low temperatures (kT=6-8 keV) favored by the most recent stellar models of the s process. Also, the two most recent high-precision measurements of the 120 Sn(n, γ) cross section are in serious disagreement. Because of its small size, this cross section could affect (via the s-process branching at 121 Sn) the relative abundances of the three s-only isotopes of Te

  19. Nuclear radiation detected optical pumping of neutron deficient Hg isotopes

    International Nuclear Information System (INIS)

    Bonn, J.

    1975-01-01

    The extension of the Nuclear Radiation Detected Optical Pumping method to mass-separated samples of isotopes far off stability is presented for a series of light Hg isotopes produced at the ISOLDE facility at CERN. The isotope under investigation is transferred by an automatic transfer system into the optical pumping apparatus. Zeeman scanning of an isotopically pure Hg spectral lamp is used to reach energetic coincidence with the hyperfine structure components of the 6s 2 1 S 0 -6s6p 3 P 1 (lambda = 2537 A) resonance line of the investigated isotope and the Hg lamp. The orientation build up by optical pumping is monitored via the asymmetry or anisotropy of the nuclear radiation. Nuclear spins, magnetic moments, electric quadrupole moments and isotopic shift are obtained for 181 Hg- 191 Hg using the β-asymmetry as detector. The extension of the method using the γ-anisotropy is discussed and measurements on 193 Hg are presented. (orig./HK)

  20. The micro-scale synthesis of (117)Sn-enriched tributyltin chloride and its characterization by GC-ICP-MS and NMR techniques.

    Science.gov (United States)

    Peeters, Kelly; Iskra, Jernej; Zuliani, Tea; Ščančar, Janez; Milačič, Radmila

    2014-07-01

    Organotin compounds (OTCs) are among the most toxic substances ever introduced to the environment by man. They are common pollutants in marine ecosystems, but are also present in the terrestrial environment, accumulated mainly in sewage sludge and landfill leachates. In investigations of the degradation and methylation processes of OTC in environmental samples, the use of enriched isotopic tracers represents a powerful analytical tool. Sn-enriched OTC are also necessary in application of the isotope dilution mass spectrometry technique for their accurate quantification. Since Sn-enriched monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) are not commercially available as single species, "in house" synthesis of individual butyltin-enriched species is necessary. In the present work, the preparation of the most toxic butyltin, namely TBT, was performed via a simple synthetic path, starting with bromination of metallic Sn, followed by butylation with butyl lithium. The tetrabutyltin (TeBT) formed was transformed to tributyltin chloride (TBTCl) using concentrated hydrochloric acid (HCl). The purity of the synthesized TBT was verified by speciation analysis using the techniques of gas chromatography coupled to inductively coupled plasma mass spectrometry (GC-ICP-MS) and nuclear magnetic resonance (NMR). The results showed that TBT had a purity of more than 97%. The remaining 3% corresponded to DBT. TBT was quantified by reverse isotope dilution GC-ICP-MS. The synthesis yield was around 60%. The advantage of this procedure over those previously reported lies in its possibility to be applied on a micro-scale (starting with 10mg of metallic Sn). This feature is of crucial importance, since enriched metallic Sn is extremely expensive. The procedure is simple and repeatable, and was successfully applied for the preparation of (117)Sn-enriched TBTCl from (117)Sn-enriched metal. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Coulomb excitation of doubly magic $^{132}$Sn with MINIBALL at HIE-ISOLDE

    CERN Multimedia

    We propose to study the vibrational first 2$^{+}$ and 3$^{-}$ states of the doubly magic nucleus $^{132}$ Sn via Coulomb excitation using the HIE-ISOLDE facility coupled with the highly efficient MINIBALL array. The intense $^{132}$Sn beam at ISOLDE, the high beam energy of HIE-ISOLDE, the high energy resolution and good efficiency of the MINIBALL provide a unique combination and favourable advantages to master this demanding measurement. Reliable B(E2;0$^{+}\\rightarrow$ 2$^{+}$) values for neutron deficient $^{106,108,110}$Sn were obtained with the MINIBALL at REX-ISOLDE. These measurements can be extended up to and beyond the shell closure at the neutron-rich side with $^{132}$Sn. The results on excited collective states in $^{132}$Sn will provide crucial information on 2p-2h cross shell configurations which are expected to be dominated by a strong proton contribution. Predictions are made within various large scale shell model calculations and new mean field calculations within the framework of different a...

  2. Mitochondrial DNA Depletion in Respiratory Chain–Deficient Parkinson Disease Neurons

    Science.gov (United States)

    Rygiel, Karolina A.; Hepplewhite, Philippa D.; Morris, Christopher M.; Picard, Martin; Turnbull, Doug M.

    2016-01-01

    Objective To determine the extent of respiratory chain abnormalities and investigate the contribution of mtDNA to the loss of respiratory chain complexes (CI–IV) in the substantia nigra (SN) of idiopathic Parkinson disease (IPD) patients at the single‐neuron level. Methods Multiple‐label immunofluorescence was applied to postmortem sections of 10 IPD patients and 10 controls to quantify the abundance of CI–IV subunits (NDUFB8 or NDUFA13, SDHA, UQCRC2, and COXI) and mitochondrial transcription factors (TFAM and TFB2M) relative to mitochondrial mass (porin and GRP75) in dopaminergic neurons. To assess the involvement of mtDNA in respiratory chain deficiency in IPD, SN neurons, isolated with laser‐capture microdissection, were assayed for mtDNA deletions, copy number, and presence of transcription/replication‐associated 7S DNA employing a triplex real‐time polymerase chain reaction (PCR) assay. Results Whereas mitochondrial mass was unchanged in single SN neurons from IPD patients, we observed a significant reduction in the abundances of CI and II subunits. At the single‐cell level, CI and II deficiencies were correlated in patients. The CI deficiency concomitantly occurred with low abundances of the mtDNA transcription factors TFAM and TFB2M, which also initiate transcription‐primed mtDNA replication. Consistent with this, real‐time PCR analysis revealed fewer transcription/replication‐associated mtDNA molecules and an overall reduction in mtDNA copy number in patients. This effect was more pronounced in single IPD neurons with severe CI deficiency. Interpretation Respiratory chain dysfunction in IPD neurons not only involves CI, but also extends to CII. These deficiencies are possibly a consequence of the interplay between nDNA and mtDNA‐encoded factors mechanistically connected via TFAM. ANN NEUROL 2016;79:366–378 PMID:26605748

  3. Laser spectroscopy of gallium isotopes using the ISCOOL RFQ cooler

    CERN Multimedia

    Blaum, K; Kowalska, M; Ware, T; Procter, T J

    2007-01-01

    We propose to study the radioisotopes of gallium (Z=31) by collinear laser spectroscopy using the ISCOOL RFQ ion cooler. The proposed measurements on $^{62-83}$Ga will span both neutron-deficient and neutron-rich isotopes. Of key interest is the suggested development of a proton-skin in the neutron-deficient isotopes. The isotope shifts measured by laser spectroscopy will be uniquely sensitive to this feature. The measurements will also provide a wealth of new information on the gallium nuclear spins, static moments and nuclear charge radii.

  4. Copper and tin isotopic analysis of ancient bronzes for archaeological investigation: development and validation of a suitable analytical methodology.

    Science.gov (United States)

    Balliana, Eleonora; Aramendía, Maite; Resano, Martin; Barbante, Carlo; Vanhaecke, Frank

    2013-03-01

    Although in many cases Pb isotopic analysis can be relied on for provenance determination of ancient bronzes, sometimes the use of "non-traditional" isotopic systems, such as those of Cu and Sn, is required. The work reported on in this paper aimed at revising the methodology for Cu and Sn isotope ratio measurements in archaeological bronzes via optimization of the analytical procedures in terms of sample pre-treatment, measurement protocol, precision, and analytical uncertainty. For Cu isotopic analysis, both Zn and Ni were investigated for their merit as internal standard (IS) relied on for mass bias correction. The use of Ni as IS seems to be the most robust approach as Ni is less prone to contamination, has a lower abundance in bronzes and an ionization potential similar to that of Cu, and provides slightly better reproducibility values when applied to NIST SRM 976 Cu isotopic reference material. The possibility of carrying out direct isotopic analysis without prior Cu isolation (with AG-MP-1 anion exchange resin) was investigated by analysis of CRM IARM 91D bronze reference material, synthetic solutions, and archaeological bronzes. Both procedures (Cu isolation/no Cu isolation) provide similar δ (65)Cu results with similar uncertainty budgets in all cases (±0.02-0.04 per mil in delta units, k = 2, n = 4). Direct isotopic analysis of Cu therefore seems feasible, without evidence of spectral interference or matrix-induced effect on the extent of mass bias. For Sn, a separation protocol relying on TRU-Spec anion exchange resin was optimized, providing a recovery close to 100 % without on-column fractionation. Cu was recovered quantitatively together with the bronze matrix with this isolation protocol. Isotopic analysis of this Cu fraction provides δ (65)Cu results similar to those obtained upon isolation using AG-MP-1 resin. This means that Cu and Sn isotopic analysis of bronze alloys can therefore be carried out after a single chromatographic

  5. In-beam studies of {sup 98}Cd and {sup 102}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Lipoglavsek, M. [Uppsala Univ. (Sweden)]|[J. Stefan Institute, Ljubljana (Slovenia); Gorska, M.; Schubart, R. [GSI, Darmstadt (Germany)] [and others

    1996-12-31

    For the first time excited states of the neutron deficient nuclei {sup 98}Cd and {sup 102}Sn were identified using in-beam spectroscopy following fusion evaporation reactions. Half lives of long lived isomeric states in both nuclei were also measured. Due to very low cross sections for producing {sup 98}Cd and {sup 102}Sn with stable beams and targets, a special detector setup utilizing NORDBALL ancillary detectors and a recoil catcher device was used. High {gamma}-ray detection efficiency was achieved with two EUROBALL Ge cluster detectors.

  6. Research within the coordinated programme on isotope-aided micronutrient studies in rice production with special reference to zinc deficiencies

    International Nuclear Information System (INIS)

    Rosales, C.M.

    1980-07-01

    An extensive survey identified 500,000 ha of soil in the Philippines as being potentially Zn-deficient for rice production. Isotope-aided laboratory, greenhouse, and field experiments were conducted to identify the most efficient methods of supplying fertilizer Zn to flooded rice. The application of 5 kg Zn/ha as ZnSO 4 effectively corrected a Zn deficiency and increased rice yield and Zn uptake for three successive growing seasons. No further increases were noted with higher rates of Zn application. Fertilizer ZnSO 4 was equally effective when mixed with the soil, combined with urea fertilizers, or surface-applied at or two weeks after transplanting the rice. Mine tailings were also shown to be an effective source of Zn. Mixing organic compost with the ZnSO 4 decreased the percent Zn derived from the fertilizer and the rice yield. 65 Zn-labelled ZnSO 4 was used

  7. Quaternary chalcogenides La{sub 3}Sn{sub 0.5}InS{sub 7} and La{sub 3}Sn{sub 0.5}InSe{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Abishek K.; Lee, Emma J.; Bernard, Guy M.; Michaelis, Vladimir K.; Mar, Arthur [Department of Chemistry, University of Alberta, Edmonton, AB (Canada); Yin, Wenlong [Department of Chemistry, University of Alberta, Edmonton, AB (Canada); Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang (China)

    2017-12-13

    The quaternary chalcogenides La{sub 3}Sn{sub 0.5}InS{sub 7} and La{sub 3}Sn{sub 0.5}InSe{sub 7} were prepared by reactions of the elements at 1050 C and 950 C, respectively. They adopt noncentrosymmetric structures [hexagonal, space group P6{sub 3}, Z = 2; a = 10.2993(11) Aa, c = 6.0921(6) Aa for La{sub 3}Sn{sub 0.5}InS{sub 7}; a = 10.6533(7) Aa, c = 6.4245(4) Aa for La{sub 3}Sn{sub 0.5}InSe{sub 7}] in which the half-occupancy of Sn atoms within octahedral sites classifies them as belonging to the La{sub 3}Mn{sub 0.5}SiS{sub 7}-type branch of the large family of quaternary rare-earth chalcogenides RE{sub 3}M{sub 1-x}M{sup '}Ch{sub 7}. The site distribution in La{sub 3}Sn{sub 0.5}InCh{sub 7}, with higher-valent Sn atoms occupying octahedral instead of tetrahedral sites, is reversed from the typical situation observed in other RE{sub 3}M{sub 1-x}M{sup '}Ch{sub 7} compounds. The ordered distribution of Sn atoms in octahedral sites and In atoms in tetrahedral sites was evaluated by bond valence sum analyses. Moreover, {sup 119}Sn solid-state nuclear magnetic resonance (NMR) spectroscopy confirms the occupation of Sn{sup 4+} species exclusively within octahedral sites. An optical bandgap of 1.45 eV was found for La{sub 3}Sn{sub 0.5}InS{sub 7}. Band structure calculations on an ordered superstructure model of La{sub 3}Sn{sub 0.5}InS{sub 7} reveal that avoidance of strongly Sn-S antibonding levels is an important driving force for the Sn deficiency. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Fueled viking generator S/N 106 acceptance vibration test report

    International Nuclear Information System (INIS)

    Anderson, C.; Brewer, C.O.; Abrahamson, S.G.

    1976-01-01

    The Viking Generator S/N 106 was vibrated to the Teledyne Isotope Flight Acceptance Schedule (Random Only) with no deviation from normal generator functional output. Radiographic analysis and power tests before and after the vibration test indicated no change in the condition of the generator. The work was conducted in the Alpha Fuels Environmental Test Facility at Mound Laboratory

  9. The interacting boson approximation and the spectroscopy of the even Cadmium and Tin isotopes

    International Nuclear Information System (INIS)

    Morrison, I.; Smith, R.

    1981-01-01

    Within the framework of the Interacting Boson Approximation (IBA), the authors investigate, using the even-mass isotopes Cd 108 to Cd 116 and Sn 116 to Sn 124 , whether a single two-boson interaction can describe the energy, B(E2), quadrupole moment and some inelastic nucleon scattering systematics of these nuclei

  10. Recent results on SN 1987A

    International Nuclear Information System (INIS)

    Woosley, S.E.; Pinto, P.A.; Weaver, T.A.

    1988-01-01

    Several critical issues recently raised by observations of SN 1987A are addressed. These include: the evolution of the pre-supernova star, why it was blue, what its composition and core structure were; the detailed isotopic composition of the ejecta; why and to what extent the supernova composition was mixed in velocity space; the interpretation of recently observed infrared lines, especially their profiles and the existence of red-shifted 'wings'; and what has become of the neutron star. 64 refs., 14 figs., 1 tab

  11. A chemically selective laser ion source for the on-line isotope separation

    International Nuclear Information System (INIS)

    Scheerer, F.

    1993-03-01

    In this thesis a laser ion source is presented. In a hot chamber the atoms of the elements to be studied are resonantly by light of pulsed dye lasers, which are pumped by pulsed copper-vapor lasers with extremely high pulse repetition rate (ν rep ∼ 10 kHz), stepwise excited and ionized. By the storage of the atoms in a hot chamber and the high pulse repetition rate of the copper-vapor lasers beyond the required high efficiency (ε ∼ 10%) can be reached. First preparing measurements were performed at the off-line separator at CERN with the rare earth elements ytterbium and thulium. Starting from the results of these measurements further tests of the laser ion source were performed at the on-line separator with in a thick tantalum target produced neutron-deficient ytterbium isotopes. Under application of a time-of-flight mass spectrometer in Mainz an efficient excitation scheme on the resonance ionization of tin was found. This excitation scheme is condition for an experiment at the GSI for the production of the extremely neutron-deficient, short-lived nucleus 102 Sn. In the summer 1993 is as first application of the newly developed laser ion source at the PSB-ISOLDE at CERN an astrophysically relevant experiment for the nuclear spectroscopy of the neutron-rich silver isotopes 124-129 Ag is planned. This experiment can because of the lacking selectivity of conventional ion sources only be performed by means of the here presented laser ion source. The laser ion source shall at the PSB-ISOLDE 1993 also be applied for the selective ionization of manganese. (orig./HSI) [de

  12. Nanoscale Cross-Point Resistive Switching Memory Comprising p-Type SnO Bilayers

    KAUST Repository

    Hota, Mrinal Kanti

    2015-02-23

    Reproducible low-voltage bipolar resistive switching is reported in bilayer structures of p-type SnO films. Specifically, a bilayer homojunction comprising SnOx (oxygen-rich) and SnOy (oxygen-deficient) in nanoscale cross-point (300 × 300 nm2) architecture with self-compliance effect is demonstrated. By using two layers of SnO film, a good memory performance is obtained as compared to the individual oxide films. The memory devices show resistance ratio of 103 between the high resistance and low resistance states, and this difference can be maintained for up to 180 cycles. The devices also show good retention characteristics, where no significant degradation is observed for more than 103 s. Different charge transport mechanisms are found in both resistance states, depending on the applied voltage range and its polarity. The resistive switching is shown to originate from the oxygen ion migration and subsequent formation/rupture of conducting filaments.

  13. Growth of intermetallics between Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layered structures

    International Nuclear Information System (INIS)

    Horváth, Barbara; Illés, Balázs; Shinohara, Tadashi

    2014-01-01

    Intermetallic growth mechanisms and rates are investigated in Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layer systems. An 8–10 μm thick Sn surface finish layer was electroplated onto a Cu substrate with a 1.5–2 μm thick Ni or Ag barrier layer. In order to induce intermetallic layer growth, the samples were aged in elevated temperatures: 50 °C and 125 °C. Intermetallic layer growth was checked by focused ion beam–scanning ion microscope. The microstructures and chemical compositions of the intermetallic layers were observed with a transmission electron microscope. It has been found that Ni barrier layers can effectively block the development of Cu 6 Sn 5 intermetallics. The intermetallic growth characteristics in the Sn/Cu and Sn/Ni/Cu systems are very similar. The intermetallic layer grows towards the Sn layer and forms a discrete layer. Differences were observed only in the growth gradients and surface roughness of the intermetallic layer which may explain the different tin whiskering properties. It was observed that the intermetallic layer growth mechanisms are completely different in the Ag barrier layers compared to the Ni layers. In the case of Sn/Ag/Cu systems, the Sn and Cu diffused through the Ag layer, formed Cu 6 Sn 5 intermetallics mainly at the Sn/Ag interface and consumed the Ag barrier layer. - Highlights: • Intermetallic growth was characterised in Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layer systems. • Intermetallic growth rates and roughness are similar in the Sn/Cu and Sn/Ni/Cu systems. • Sn/Ni/Cu system contains the following intermetallic layer structure Sn–Ni3Sn4–Ni3Sn2–Ni3Sn–Ni. • In the case of Sn/Ag/Cu systems the Sn and Cu diffusion consumes the Ag barrier layer. • When Cu reaches the Sn/Ag interface a large amount of Cu 6 Sn 5 forms above the Ag layer

  14. Comparative evaluation of quantitative glomerular filtration rate measured by isotopic and nonisotopic methods

    International Nuclear Information System (INIS)

    Balachandran, S.; Toguri, A.G.; Petrusick, T.W.; Abbott, L.C.

    1981-01-01

    Good correlation of glomerular filtration rate (GFR) measured isotopically from plasma disappearance of Tc-99m-DTPA (Sn) was shown with inulin clearance, creatinine clearance, and graded radionuclide imaging. The isotopic GFR is a simple, urineless technique not requiring continuous infusion that enables one to perform simultaneous renal imaging with one radiotracer

  15. Investigations on the structures of sup(99m)Tc and 113Sn pyrophosphate complexes and of sup(99m)Tc and 113Sn ethane hydroxy diphosphate complexes

    International Nuclear Information System (INIS)

    Hohloch, M.

    1980-01-01

    The complex formation of double labelling of bivalent 113 Sn and reduced, quadrovalent sup(99m)Tc with pyrophosphate (PPi) or ethane hydroxy diphosphorate (EHDP) has been investigated by means of in vivo distribution in the rat. The molar rates of sup(99m)Tc and 113 Sn to PPi resp. EHDP, as well as the pH-value and the initial concentration is varied. Furthermore, both elements were oxidized with H 2 O 2 in the alkaline medium. Four typical sup(99m)Tc and two typical 113 Sn in-vivo distribution patterns can be differentiated: 1. Pertechnetate, characterized by a strong enrichment in the stomach, forms when all Sn-II has been oxidized to Sn-IV in the preparation. 2. One bone-seeking 113 Sn-II PPi (EHDP) complex and a sup(99m)Tc-IV PPi (EHDP) complex each, which are formed at least equimolar ratio of Sn to PPi (EHDP) and suffiently high concentration of PPi (EHDP) in the physiological pH-value. 3. A non-bone-seeking sup(99m)Tc-IV compound, which is enriched in the kidneys instead, is formed in the weakly alkaline medium or at low PPi (EHDP) concentration. This is probably monomeric technetium dioxide dihydrate. 4. A sup(99m)Tc as well as a Sn colloid is formed at deficient ligand concentration (PPi or EHDP to Sn). The chemical composition of the complexes is discussed the possible reaction courses are illustrated in the following diagrams. (orig./MG) [de

  16. Stable isotope and fluid inclusion evidence for the origin of the Brandberg West area Sn-W vein deposits, NW Namibia

    Science.gov (United States)

    Macey, Paul; Harris, Chris

    2006-10-01

    The Brandberg West region of NW Namibia is dominated by poly-deformed turbidites and carbonate rocks of the Neoproterozoic Damara Supergoup, which have been regionally metamorphosed to greenschist facies and thermally metamorphosed up to mid-amphibolite facies by Neoproterozoic granite plutons. The meta-sedimentary rocks host Damaran-age hydrothermal quartz vein-hosted Sn-W mineralization at Brandberg West and numerous nearby smaller deposits. Fluid inclusion microthermometric studies of the vein quartz suggests that the ore-forming fluids at the Brandberg West mine were CO2-bearing aqueous fluids represented by the NaCl-CaCl2-H2O-CO2 system with moderate salinity (mean=8.6 wt% NaClequivalent).Temperatures determined using oxygen isotope thermometry are 415-521°C (quartz-muscovite), 392-447°C (quartz-cassiterite), and 444-490°C (quartz-hematite). At Brandberg West, the oxygen isotope ratios of quartz veins and siliciclastic host rocks in the mineralized area are lower than those in the rocks and veins of the surrounding areas suggesting that pervasive fluid-rock interaction occurred during mineralization. The O- and H-isotope data of quartz-muscovite veins and fluid inclusions indicate that the ore fluids were dominantly of magmatic origin, implying that mineralization occurred above a shallow granite pluton. Simple mass balance calculations suggest water/rock ratios of 1.88 (closed system) and 1.01 (open system). The CO2 component of the fluid inclusions had similar δ 13C to the carbonate rocks intercalated with the turbidites. It is most likely that mineralization at Brandberg West was caused by a combination of an impermeable marble barrier and interaction of the fluids with the marble. The minor deposits in the area have quartz veins with higher δ 18O values, which is consistent with these deposits being similar geological environments exposed at higher erosion levels.

  17. Comparison of the electrochemical performance of mesoscopic Cu2Sb, SnSb and Sn/SnSb alloy powders

    International Nuclear Information System (INIS)

    Zhang Ge; Huang Kelong; Liu Suqin; Zhang Wei; Gong Benli

    2006-01-01

    Cu 2 Sb, SnSb and Sn/SnSb mesoscopic alloy powders were prepared by chemical reduction, respectively. The crystal structures and particle morphology of Cu 2 Sb, SnSb and Sn/SnSb were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The electrochemical performances of the Cu 2 Sb, SnSb and Sn/SnSb electrodes were investigated by galvanostatic charge and discharge cycling and electrochemical impedance spectroscopy (EIS). The results showed the first charge and discharge capacities of SnSb and Sn/SnSb were higher than Cu 2 Sb, but after 15 cycles, the charge capacity fading rates of Cu 2 Sb, Sn/SnSb and Sn/SnSb were 26.16%, 55.33% and 47.39%, respectively. Cu 2 Sb had a better cycle performance, and Sn/SnSb multiphase alloy was prior to pure SnSb due to the existence of excessive Sn in Sn/SnSb system

  18. Production and separation of neutron-rich rare isotopes around and below the Fermi energy

    CERN Document Server

    Souliotis, G A; Chubarian, G; Yennello, S J

    2003-01-01

    The production of n-rich rare isotopes around and below the Fermi energy is investigated using beams from the K500 Superconducting Cyclotron and the MARS recoil separator at the Cyclotron Institute of Texas A and M University. The experimental results from the reactions of 25 MeV/nucleon sup 8 sup 6 Kr + sup 6 sup 4 Ni and 21 MeV/nucleon sup 1 sup 2 sup 4 Sn + sup 1 sup 2 sup 4 Sn are presented and compared with simulations. The calculations involve a deep inelastic transfer (DIT) code for the primary interaction stage followed by the code GEMINI for the de-excitation stage. The results are also compared with the EPAX parametrization. The data on the 25 MeV/nucleon sup 8 sup 6 Kr + sup 6 sup 4 Ni reaction show that both proton-removal and several-neutron pick-up isotopes are produced. An enhancement is observed in the production of n-rich isotopes close to the projectile relative to the predictions of DIT/GEMINI and the expectations of EPAX. The data of 21 MeV/nucleon sup 1 sup 2 sup 4 Sn + sup 1 sup 2 sup 4 ...

  19. Effects of copper excess and copper deficiency on the structural and electrical properties of bulk Cu{sub x}SnSe{sub 3} with x=1.6–2.2

    Energy Technology Data Exchange (ETDEWEB)

    Wubet, Walelign; Kuo, Dong-Hau, E-mail: dhkuo@mail.ntust.edu.tw

    2015-03-15

    Effects of the Cu variation on the morphological, structural, and electrical properties of bulk Cu{sub x}SnSe{sub 3} (CTSe) with x=1.6–2.2 have been investigated. Dense CTSe pellets with grains of 3–4 µm were obtained after sintering at 550 °C. All CTSe pellets showed a dominant p-type behavior. CTSe at x=2.0 with a hole concentration (n{sub p}) of 1.02×10{sup 18} cm{sup −3} and Hall mobility (μ) of 225 cm{sup 2}/V/s had a highest conductivity (σ) of 39 S/cm. CTSe at x=1.6 with n{sub p} of 5.0×10{sup 17} cm{sup −3} and of 11 cm{sup 2}/V/s had a lowest of 0.90 S/cm. The explanation, based upon vacancies and antisite defects, for the changes in electrical property with the Cu content is supported by the data from lattice parameter. The study in bulk properties of CTSe and its defects is helpful for selecting the suitable absorber composition to fabricate thin film solar cells. - Graphical abstract: Cu{sub 2}SnSe{sub 3} is an absorber candidate for solar cells. The Cu stoichiometry on electrical properties, which is important for CIGS and CZTS, is investigated and the Cu-deficiency composition is recommended. - Highlights: • Cu{sub x}SnSe{sub 3} (CTSe) bulks with 1.6≤x≤2.2 were prepared by reactive sintering. • Cu{sub 2}SnSe{sub 3} with n{sub p} of 1.02×10{sup 18} cm{sup −3} and μ of 225 cm{sup 2}/V/s had highest σ of 39 S/cm. • Cu{sub 1.6}SnSe{sub 3} with n{sub p}=5.0×10{sup 17} cm{sup −3} and μ=11 cm{sup 2}/V/s had lowest σ=0.90 S/cm. • Lower n{sub p} at CTSe at x=1.6 is related to the formation of the Sn-to-Cu defect. • The drop in n{sub p} for CTSe at x=2.2 indicates V{sub Sn}{sup 4−} dominates over Cu{sub Sn}{sup 3−} defect.

  20. Determination of Sn in 99mTc Radiopharmaceutical Kits by Polarographic Methods

    International Nuclear Information System (INIS)

    Castro, M.; Cruz, J.; Sanchez, M.

    2009-01-01

    Kits of 99 m Tc radiopharmaceuticals are used in nuclear medicine for diagnosis of different diseases. Sn (II) is one of the essential components in their formulations, which is used for reduction 99 m Tc-pertechnetate in cold kits for on-site preparation 99 m Tc-pertechnetate radiopharmaceuticals. Usually, these cold kits contain different additives (complexing agents, antioxidants, buffers, etc.) and the amount of Sn (II) varies from kit to kit. The determination of Sn in these products is essential in assessing their quality. We report here the development of a new polarographic method for the determination of Sn (II) and total Sn in representative radiopharmaceuticals kits (for the content of Sn and chemical composition) produced at the Center of Isotopes of Cuba (CENTIS). These methods were validated by analysis of variance and recovery techniques. From the results of the validation, the characteristic functions of uncertainties and fits are considered for the established methods, which give the necessary evidences to demonstrate the usefulness of these methods according to the current trends in Analytical Chemistry. This work provides practical results of great importance for CENTIS. After the speciation of Sn in the MAG3 radiopharmaceuticals kit is inferred that the production process is affected by uncontrolled factors that influence in the product stability, which demonstrates the necessity for analytical tools for the characterization of products and processes. (Author) 57 refs.

  1. Narrowband Hα Imaging of Old Hydrogen-deficient Supernovae

    Science.gov (United States)

    Pooley, David A.; Vinko, Jozsef; Silverman, Jeffrey M.; Wheeler, J. Craig Craig; Szalai, Tamas; MacQueen, Phillip; Marion, Howie H.; Sárneczky, Krisztián

    2017-06-01

    We report results from our long-term observational survey aimed at discovering late-time interaction between the ejecta of hydrogen-deficient Type I supernovae and the hydrogen-rich envelope expelled from the progenitor star several decades to centuries before explosion. The expelled envelope, moving with a velocity of ˜10-100 km/s, is expected to be caught up by the fast-moving SN ejecta several years to decades after explosion depending on the history of the mass-loss process acting in the progenitor star prior to explosion. The collision between the SN ejecta and the circumstellar envelope results in net emission in the Balmer-lines, especially in Hα. For the past three years, we have been using the Direct Imaging Auxiliary Functions Instrument (DIAFI) on the 2.7m Harlan J. Smith Telescope at McDonald Observatory to look for signs of late-time Hα emission in older Type Ia/Ibc/IIb SNe having hydrogen-poor ejecta, via narrow-band imaging. Continuum-subtracted Hα emission has been detected for 13 point sources: 9 SN Ibc, 1 SN IIb and 3 SN Ia events. Thirty-eight SN sites were observed on at least two epochs, from which three objects (SN 1985F, SN 2005kl, SN 2012fh) showed significant temporal variation in the strength of their Hα emission in our DIAFI data. This suggests that the variable emission is probably not due to nearby HII regions, and hence is an important additional hint that ejecta-CSM interaction may take place in these systems. Moreover, we successfully detected the late-time Hα emission from the Type Ib SN 2014C, which was recently discovered as a strongly interacting SN in other wavebands.

  2. Optimization of determination of 126Sn by ion exchange chromatography method (presentation)

    International Nuclear Information System (INIS)

    Pasteka, L.; Dulanska, S.

    2013-01-01

    The aim of the work is to optimize the uptake of tin on anion exchange resins and application of this knowledge for the analysis of samples of radioactive waste from the device of Jaslovske Bohunice and Mochovce in determining of 126 Sn. First to be optimized a method for the separation of tin on ion exchange sorbent Anion Exchange Resin (1-X8, Chloride Form) from Eichrom Technologies. Model sample was prepared in 7 mol dm -3 HCl, because in that environment a sorbent effectively captures the tin, which is bounded complexly with chloride anions as SnCl 6 2- . The radiochemical separation yield was monitored by gamma spectrometric measurements on high purity germanium detector HPGe (E = 391 keV) by adding isotope 113 Sn to each model solution. The method of tin separation was optimized on model samples.

  3. Geochronology and Genesis of the Xitian W-Sn Polymetallic Deposit in Eastern Hunan Province, South China: Evidence from Zircon U-Pb and Muscovite Ar-Ar Dating, Petrochemistry, and Wolframite Sr-Nd-Pb Isotopes

    Directory of Open Access Journals (Sweden)

    Jingya Cao

    2018-03-01

    Full Text Available The recently explored Xitian tungsten-tin (W-Sn polymetallic ore field, located in Hunan province, South China, is one of the largest ore fields in the Nanling Range (NLR. Two major metallogenic types appeared in this ore field, skarn- and quartz vein-type. They are distributed within Longshang, Heshuxia, Shaiheling, Hejiangkou, Goudalan, and so on. Hydrothermal zircons from two altered granites yielded U-Pb ages of 152.8 ± 1.1 Ma, and 226.0 ± 2.8 Ma, respectively. Two muscovite samples from ore-bearing quartz vein yielded 40Ar/39Ar plateau ages of 156.6 ± 0.7 Ma, 149.5 ± 0.8 Ma, respectively. Combined with the geological evidence, two metallogenic events are proposed in the Xitian ore field, with skarn-type W-Sn mineralization in Late Triassic (Indosinian and quartz vein/greisen type W-Sn mineralization in Late Jurassic (Yanshanian. The relatively low Ce/Ce* ratios and high Y/Ho ratios in zircons from two altered granites indicate that the hydrothermal fluids of two metallogenic events are characterized by low oxygen fugacities and enrichment in F. The similar chondrite-normalized patterns between the skarn and Xitian Indosinian granites and Sr-Nd-Pb isotopic compositions of wolframite suggest that the metal sources for both types W-Sn mineralization are derived from a crustal source.

  4. Yrast spectroscopy in the neutron-deficient nucleus 169Os

    International Nuclear Information System (INIS)

    Joss, D.T.; Simpson, J.; Appelbe, D.E.; Warner, D.D.; Page, R.D.; King, S.L.; Amzal, N.; Cullen, D.M.; Greenlees, P.T.; Keenan, A.; Baeck, T.; Cederwall, B.; Wyss, R.; Bentley, M.A.; Williams, S.J.; Cocks, J.F.C.; Helariutta, K.; Jones, P.M.; Julin, R.; Juutinen, S.

    2002-01-01

    Excited states in the neutron-deficient isotope 169 Os have been identified for the first time in an experiment using the Jurosphere γ-ray spectrometer in conjunction with the Ritu gas-filled recoil separator. The problems associated with identifying neutron-deficient isotopes produced with low fusion cross sections against a high background of competing channels, including fission, have been overcome by using the recoil-decay tagging technique. The band structures observed in 169 Os are interpreted in the context of the systematics of neighboring nuclei and the predictions of cranked Woods-Saxon calculations. The systematics of the second (i 13/2 ) 2 neutron alignment in this region are discussed

  5. Realistic nuclear shell theory and the doubly-magic 132Sn region

    International Nuclear Information System (INIS)

    Vary, J.P.

    1978-01-01

    After an introduction discussing the motivation and interest in results obtained with isotope separators, the fundamental problem in realistic nuclear shell theory is posed in the context of renormalization theory. Then some of the important developments that have occurred over the last fifteen years in the derivation of the effective Hamiltonian and application of realistic nuclear shell theory are briefly reviewed. Doubly magic regions of the periodic table and the unique advantages of the 132 Sn region are described. Then results are shown for the ground-state properties of 132 Sn as calculated from the density-dependent Hartree-Fock approach with the Skyrme Hamiltonian. A single theoretical Hamiltonian for all nuclei from doubly magic 132 Sn to doubly magic 208 Pb is presented; single-particle energies are graphed. Finally, predictions of shell-model level-density distributions obtained with spectral distribution methods are discussed; calculated level densities are shown for 136 Xe. 10 figures

  6. Identification of new neutron-rich actinide isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Oura, Yasuji; Sakama, Minoru; Ohyama, T. [Tokyo Metropolitan Univ. (Japan)] [and others

    1999-10-01

    To advance research on new neutron-deficient actinide isotopes using an on-line isotope separator combined with a gas-jet injector installed in the JAERI Tandem accelerator, Tokai, performance test of the equipment was carried out. Efficiency of the product isotopes being transported from the target chamber to the measuring system was greatly improved by employing lead iodides (PbI{sub 2}) as the aerosol carrier. With the help of this technique, the authors succeeded in synthesizing and identifying actinide isotopes, {sup 235}Am and {sup 236}Am, and measured their alpha-decay half-life. (S. Ohno)

  7. SN Refsdal

    DEFF Research Database (Denmark)

    Kelly, P. L.; Brammer, G.; Selsing, J.

    2016-01-01

    (SNe), and we find strong evidence for a broad H-alpha P-Cygni profile in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn, powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show...... in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, SN Refsdal has a blue B-V color and a high luminosity for the assumed range of potential magnifications. If SN Refsdal can be modeled as a scaled version of SN...

  8. 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 ...

  9. Shape coexistence in selenium isotopes

    International Nuclear Information System (INIS)

    Liu Ying; Cao Zhongbin; Xu Furong

    2010-01-01

    Nuclear shape change and shape coexistence in the Selenium isotopes have been investigated by Total-Routhian-Surface (TRS) calculations. It is found that nuclear shapes vary significantly with increasing neutron number. The TRS calculations for the ground states of 66,72,92,94 Se isotopes show that both neutron-deficient and neutron-dripline Selenium isotopes have oblate and prolate shape coexistence. The cranking shell-model calculations for 72,94 Se give that prolate and oblate shape coexistence in low rotational frequency. However, oblate rotational bands disappear and prolate rotational bands become yrast bands with increasing rotational frequency, which is due to the intrusion of the g 9/2 orbitals. (authors)

  10. Nuclear structure around doubly-magic nuclei: lifetime measurements in the vicinity of 68Ni and search for isomers around 100Sn

    International Nuclear Information System (INIS)

    Celikovic, Igor

    2013-01-01

    In this thesis we investigated the structure of nuclei around 68 Ni as well as the production, separation and identification of proton-rich isotopes lying in the vicinity of the doubly-magic 100 Sn nucleus.In the first part, we discuss the evolution of collectivity and the interplay between collective and single-particle degrees of freedom in nuclei around 68 Ni. We measured lifetimes in Zn isotopes around N = 40 produced in 238 U + 70 Zn deep-inelastic collisions at GANIL. We used a plunger device and the recoil-distance Doppler-shift method. The nuclei of interest were identified by the VAMOS spectrometer and the γ-rays with the EXOGAM array. The reduced electromagnetic transitions probabilities were extracted from the lifetimes. Several transitions and lifetimes are reported for the first time. The experimental results are discussed in the framework of shell model calculations. In the second part, the partial conservation of seniority in the g 9/2 shell and its influence on one-particle transfer is discussed. The third part presents the analysis of an in-beam test performed at RIKEN (Japan) to evaluate two settings of the BigRIPS separator for optimizing the production and selection of 100 Sn. This study has been used to setup our subsequent experiment, dedicated to the measurement of the Gamow-Teller strength in the decay of 100 Sn, to the mapping of the proton drip-line and the study of short-lived isomers in this mass region. Nuclei around 100 Sn were produced by fragmentation of a 345 MeV/u 124 Xe beam on a Be target. The production cross-sections of nuclei around 100 Sn were measured. The search for new isotopes and new isomers in all identified nuclei is presented. (author) [fr

  11. Segregation and microstructure evolution in chill cast and directionally solidified Ni-Mn-Sn metamagnetic shape memory alloys

    Science.gov (United States)

    Czaja, P.; Wierzbicka-Miernik, A.; Rogal, Ł.

    2018-06-01

    A multiphase solidification behaviour is confirmed for a range of Ni-rich and Ni-deficient Ni-Mn-Sn induction cast and directionally solidified (Bridgman) alloys. The composition variation is primarily linked to the changing Mn/Sn ratio, whereas the content of Ni remains largely stable. The partitioning coefficients for the Ni50Mn37Sn13 and Ni46Mn41.5Sn12.5 Bridgman alloys were obtained according to the Scheil equation based on the composition distribution along the longitudinal cross section of the ingots. Homogenization heat treatment performed for 72 h at 1220 K turned out sufficient for ensuring chemical uniformity on the macro- and microscale. It is owed to a limited segregation length scale due to slow cooling rates adopted for the directional solidification process.

  12. Studies of neutron-deficient mendelevium isotopes at SHIP

    Energy Technology Data Exchange (ETDEWEB)

    Antalic, S.; Saro, S. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Hessberger, F.P.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt am Main (Germany); Kuusiniemi, P. [University of Oulu, Centre for Underground Physics in Pyhaesalmi (CUPP), Oulu (Finland); Leino, M. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland)

    2010-01-15

    The radioactive decay of the isotopes {sup 247}Md, {sup 246}Md and their daughter products was investigated by means of {alpha}-{alpha} and {alpha}-{gamma} coincidence spectroscopy. The isotopes were produced using the fusion reaction {sup 40}Ar + {sup 209}Bi. Decay schemes are suggested for {sup 247}Md and {sup 243}Es. A new isomeric state in {sup 246}Md with a half-life of (4.4{+-}0.8) s was observed. Previous data of electron-capture delayed fission of {sup 246}Md and {sup 242}Es were confirmed. The probability for this decay branch in {sup 246}Md was measured to be P{sub ECDF}>0.10. The probability for electron-capture delayed fission in the case of {sup 242}Es was determined to be P{sub ECDF}=0.013{sup +0.012} {sub -0.007}. (orig.)

  13. Laser Spectroscopy Study on the Neutron-Rich and Neutron-Deficient Te Isotopes

    CERN Multimedia

    2002-01-01

    We propose to perform laser spectroscopy measurements on the Te isotopes. This will give access to fundamental properties of the ground and rather long-lived isomeric states such as the change in the mean square charge radius ($\\delta\\langle$r$^2_c\\rangle$) and the nuclear moments. For these medium-mass isotopes, at this moment the optical resolution obtained with RILIS is not high enough to perform isotope shift measurements. Thus we will use the COMPLIS experimental setup which allows Resonant Ionization Spectroscopy (RIS) on laser desorbed atoms. The 5p$^{4}$ $^{3}$P$_{2} \\rightarrow$ 5p$^{3}$ 6s $^{3}$S$_{1}$ and 5p$^{4}$ $^{3}$P$_{2} \\rightarrow$ 5p$^{3}$ 6s $^{5}$S$_{2}$ optical transitions have been used to perform, on the stable Te isotopes, the tests required by the INTC committee. For this purpose stable-ion sources have been built and Te isotopes have been delivered as stable beams by the injector coupled to the COMPLIS setup. ISOLDE offers the opportunity for studying the Te isotope series over a ...

  14. Systematics of the electric dipole response in stable tin isotopes

    Science.gov (United States)

    Bassauer, Sergej; von Neumann-Cosel, Peter; Tamii, Atsushi

    2018-05-01

    The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP), Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

  15. Systematics of the electric dipole response in stable tin isotopes

    Directory of Open Access Journals (Sweden)

    Bassauer Sergej

    2018-01-01

    Full Text Available The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP, Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

  16. The high-temperature modification of LuAgSn and high-pressure high-temperature experiments on DyAgSn, HoAgSn, and YbAgSn

    Energy Technology Data Exchange (ETDEWEB)

    Heying, B.; Rodewald, U.C.; Hermes, W.; Schappacher, F.M.; Riecken, J.F.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, G.; Huppertz, H. [Muenchen Univ. (Germany). Dept. fuer Chemie und Biochemie; Sebastian, C.P. [Max-Planck-Institut fuer Chemische Physik Fester Stoffe, Dresden (Germany)

    2008-02-15

    The high-temperature modification of LuAgSn was obtained by arc-melting an equiatomic mixture of the elements followed by quenching the melt on a water-cooled copper crucible. HT-LuAgSn crystallizes with the NdPtSb-type structure, space group P6{sub 3}mc: a = 463.5(1), c = 723.2(1) pm, wR2 = 0.0270, 151 F{sup 2}, and 11 variables. The silver and tin atoms build up two-dimensional, puckered [Ag{sub 3}Sn{sub 3}] networks (276 pm Ag-Sn) that are charge-balanced and separated by the lutetium atoms. The Ag-Sn distances between the [Ag{sub 3}Sn{sub 3}] layers of 294 pm are much longer. Single crystals of isotypic DyAgSn (a = 468.3(1), c = 734.4(1) pm, wR2 = 0.0343, 411 F{sup 2}, and 11 variables) and HoAgSn (a = 467.2(1), c = 731.7(2) pm, wR2 = 0.0318, 330 F{sup 2}, and 11 variables) were obtained from arc-melted samples. Under high-pressure (up to 12.2 GPa) and high-temperature (up to 1470 K) conditions, no transitions to a ZrNiAl-related phase have been observed for DyAgSn, HoAgSn, and YbAgSn. HT-TmAgSn shows Curie-Weiss paramagnetism with {mu}{sub eff} = 7.53(1) {mu}{sub B}/Tm atom and {theta}P = -15.0(5) K. No magnetic ordering was evident down to 3 K. HT-LuAgSn is a Pauli paramagnet. Room-temperature {sup 119}Sn Moessbauer spectra of HT-TmAgSn and HT-LuAgSn show singlet resonances with isomer shifts of 1.78(1) and 1.72(1) mm/s, respectively. (orig.)

  17. Effect of thickness on optical properties of thermally evaporated SnS films

    International Nuclear Information System (INIS)

    Selim, M.S.; Gouda, M.E.; El-Shaarawy, M.G.; Salem, A.M.; Abd El-Ghany, W.A.

    2013-01-01

    The effect of film thickness on the structure and optical properties of thermally evaporated SnS film has been studied. SnS films with different thicknesses in the range 152–585 nm were deposited onto clean glass substrates at room temperature. X-ray diffraction study revealed that SnS films of thickness ≥ 283 nm are crystalline, whereas films of lower thickness exhibit poor crystalline with more amorphous background. The crystalline nature of the lower film thickness has been confirmed using transmission electron microscope and the corresponding electron diffraction pattern. The thicker film samples showed nearly stoichiometric chemical composition; however, thinner samples are deficient in S and rich in Sn. The optical property of the deposited films has been investigated in the wavelength range 350–2500 nm. The refractive index increases notably with increasing film thickness. The refractive index for the investigated film thicknesses are adequately described by the effective-single-oscillator model. The static refractive index and the static dielectric constant have been calculated. Analysis of the optical absorption coefficient revealed the presence of direct optical transition and the corresponding band gap values were found to decrease as the film thickness increases. - Highlights: ► X-ray diffraction was used to study the structure of SnS films. ► Transmission electron microscope confirms the crystalline state of SnS films. ► The refractive index increases notably with increasing the film thickness. ► The optical band gap of SnS films decreases with increasing film thickness

  18. Isoscaling in central {sup 124}Sn+{sup 64}Ni, {sup 112}Sn+{sup 58}Ni collisions at 35 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Geraci, E.; Bruno, M.; D' Agostino, M. E-mail: dagostino@bo.infn.it; De Filippo, E.; Pagano, A.; Vannini, G.; Alderighi, M.; Anzalone, A.; Auditore, L.; Baran, V.; Barna, R.; Bartolucci, M.; Berceanu, I.; Blicharska, J.; Bonasera, A.; Borderie, B.; Bougault, R.; Brzychczyk, J.; Cardella, G.; Cavallaro, S.; Chbihi, A.; Cibor, J.; Colonna, M.; De Pasquale, D.; Di Toro, M.; Giustolisi, F.; Grzeszczuk, A.; Guazzoni, P.; Guinet, D.; Iacono-Manno, M.; Italiano, A.; Kowalski, S.; La Guidara, E.; Lanzalone, G.; Lanzano, G.; Le Neindre, N.; Li, S.; Lo Nigro, S.; Maiolino, C.; Majka, Z.; Manfredi, G.; Paduszynski, T.; Papa, M.; Petrovici, M.; Piasecki, E.; Pirrone, S.; Politi, G.; Pop, A.; Porto, F.; Rivet, M.F.; Rosato, E.; Russo, S.; Russotto, P.; Sechi, G.; Simion, V.; Sperduto, M.L.; Steckmeyer, J.C.; Trifiro, A.; Trimarchi, M.; Vigilante, M.; Wieleczko, J.P.; Wilczynski, J.; Wu, H.; Xiao, Z.; Zetta, L.; Zipper, W

    2004-02-23

    {sup 124}Sn+{sup 64}Ni and {sup 112}Sn+{sup 58}Ni reactions at 35 A MeV incident energy were studied by using the 688 Si-CsI telescopes of the forward part (1 deg. {<=}{theta}{sub lab}{<=}30 deg.) of CHIMERA multi-detector. The most central part, 1% of the total measured cross section was selected by means of a multidimensional analysis of the experimental observables. The detected isotopes of light fragments (3{<=}Z{<=}8) provided information on breakup temperatures of the emitting sources. The space-time structure of these sources was deduced from fragment correlations. An odd-even effect in the fragment production, enhanced by the isospin of the entrance channel, was observed. Freeze-out unbound neutron-to-proton relative densities for both studied reactions have been deduced, indicating for a possible isospin distillation mechanism related to a phenomenon of the liquid-gas phase transition in asymmetric systems.

  19. High-resolution photoluminescence spectroscopy of Sn-doped ZnO single crystals

    International Nuclear Information System (INIS)

    Kumar, E. Senthil; Mohammadbeigi, F.; Boatner, L.A.; Watkins, S.P.

    2016-01-01

    Group IV donors in ZnO are poorly understood, despite evidence that they are effective n-type dopants. Here we present high-resolution photoluminescence (PL) spectroscopy studies of unintentionally doped and Sn-doped ZnO single crystals grown by the chemical vapor transport method. Doped samples showed greatly increased emission from the I 10 bound exciton transition that was recently proven to be related to the incorporation of Sn impurities based on radio-isotope studies. The PL linewidths are exceptionally sharp for these samples, enabling a clear identification of several donor species. Temperature-dependent PL measurements of the I 10 line emission energy and intensity dependence reveal a behavior that is similar to other shallow donors in ZnO. Ionized donor bound-exciton and two-electron satellite transitions of the I 10 transition are unambiguously identified and yield a donor binding energy of 71 meV. In contrast to recent reports of Ge-related donors in ZnO, the spectroscopic binding energy for the Sn-related donor bound exciton follows a linear relationship with donor binding energy (Haynes rule) similar to recently observed carbon related donors, and confirming the shallow nature of this defect center, which was recently attributed to a Sn Zn double donor compensated by an unknown single acceptor.

  20. Pseudomorphic GeSiSn, SiSn and Ge layers in strained heterostructures

    Science.gov (United States)

    Timofeev, V. A.; Nikiforov, A. I.; Tuktamyshev, A. R.; Mashanov, V. I.; Loshkarev, I. D.; Bloshkin, A. A.; Gutakovskii, A. K.

    2018-04-01

    The GeSiSn, SiSn layer growth mechanisms on Si(100) were investigated and the kinetic diagrams of the morphological GeSiSn, SiSn film states in the temperature range of 150 °C-450 °C at the tin content from 0% to 35% were built. The phase diagram of the superstructural change on the surface of Sn grown on Si(100) in the annealing temperature range of 0 °C-850 °C was established. The specular beam oscillations were first obtained during the SiSn film growth from 150 °C to 300 °C at the Sn content up to 35%. The transmission electron microscopy and x-ray diffractometry data confirm the crystal perfection and the pseudomorphic GeSiSn, SiSn film state, and also the presence of smooth heterointerfaces between GeSiSn or SiSn and Si. The photoluminescence for the multilayer periodic GeSiSn/Si structures in the range of 0.6-0.8 eV was detected. The blue shift with the excitation power increase is observed suggesting the presence of a type II heterostructure. The creation of tensile strained Ge films, which are pseudomorphic to the underlying GeSn layer, is confirmed by the results of the formation and analysis of the reciprocal space map in the x-ray diffractometry. The tensile strain in the Ge films reached the value in the range of 0.86%-1.5%. The GeSn buffer layer growth in the Sn content range from 8% to 12% was studied. The band structure of heterosystems based on pseudomorphic GeSiSn, SiSn and Ge layers was calculated and the valence and conduction band subband position dependences on the Sn content were built. Based on the calculation, the Sn content range in the GeSiSn, SiSn, and GeSn layers, which corresponds to the direct bandgap GeSiSn, SiSn, and Ge material, was obtained.

  1. Reference Data for the Density, Viscosity, and Surface Tension of Liquid Al-Zn, Ag-Sn, Bi-Sn, Cu-Sn, and Sn-Zn Eutectic Alloys

    Science.gov (United States)

    Dobosz, Alexandra; Gancarz, Tomasz

    2018-03-01

    The data for the physicochemical properties viscosity, density, and surface tension obtained by different experimental techniques have been analyzed for liquid Al-Zn, Ag-Sn, Bi-Sn, Cu-Sn, and Sn-Zn eutectic alloys. All experimental data sets have been categorized and described by the year of publication, the technique used to obtain the data, the purity of the samples and their compositions, the quoted uncertainty, the number of data in the data set, the form of data, and the temperature range. The proposed standard deviations of liquid eutectic Al-Zn, Ag-Sn, Bi-Sn, Cu-Sn, and Sn-Zn alloys are 0.8%, 0.1%, 0.5%, 0.2%, and 0.1% for the density, 8.7%, 4.1%, 3.6%, 5.1%, and 4.0% for viscosity, and 1.0%, 0.5%, 0.3%, N/A, and 0.4% for surface tension, respectively, at a confidence level of 95%.

  2. The properties of atomic nuclei at the boundary of proton instability, discussed at the example of very neutron deficient isotopes in the mass range 100-150

    International Nuclear Information System (INIS)

    Roeckl, E.

    1981-10-01

    In this paper it shall be tried to strike the balance after the first years of experimenting at the on-line mass separator of the GSI Darmstadt and to present the main results of the study of very neutron deficient isotopes in the mass range 90-150 as well as the resulting questions for further experiments. First some foundations concerning the properties of neutron deficient nuclei and the measuring method are explained. The results and their interpretation are discussed using examples for the alpha decay, the beta decay, the mass-energy-area, and the proton-drip line. Finally the obtained results are summarized, and an outlook to further studies of nuclear properties far from beta stability is given. (orig.) [de

  3. Study of polonium isotopes ground state properties by simultaneous atomic- and nuclear-spectroscopy

    CERN Multimedia

    Koester, U H; Kalaninova, Z; Imai, N

    2007-01-01

    We propose to systematically study the ground state properties of neutron deficient $^{192-200}$Po isotopes by means of in-source laser spectroscopy using the ISOLDE laser ion source coupled with nuclear spectroscopy at the detection setup as successfully done before by this collaboration with neutron deficient lead isotopes. The study of the change in mean square charge radii along the polonium isotope chain will give an insight into shape coexistence above the mid-shell N = 104 and above the closed shell Z = 82. The hyperfine structure of the odd isotopes will also allow determination of the nuclear spin and the magnetic moment of the ground state and of any identifiable isomer state. For this study, a standard UC$_{x}$ target with the ISOLDE RILIS is required for 38 shifts.

  4. Shape coexistence in neutron-deficient Hg isotopes studied via lifetime measurements in $^{184,186}$Hg and two-state mixing calculations

    CERN Document Server

    Gaffney, L P; Page, R.D.; Grahn, T.; Scheck, M.; Butler, P.A.; Bertone, P.F.; Bree, N.; Carroll, R.J.; Carpenter, M.P.; Chiara, C.J.; Dewald, A.; Filmer, F.; Fransen, C.; Huyse, M.; Janssens, R.V.F.; Joss, D.T.; Julin, R.; Kondev, F.G.; Nieminen, P.; Pakarinen, J.; Rigby, S.V.; Rother, W.; Van Duppen, P.; Watkins, H.V.; Wrzosek-Lipska, K.; Zhu, S.

    2014-01-01

    The neutron-deficient mercury isotopes, $^{184,186}$Hg, were studied with the Recoil Distance Doppler Shift (RDDS) method using the Gammasphere array and the K\\"oln Plunger device. The Differential Decay Curve Method (DDCM) was employed to determine the lifetimes of the yrast states in $^{184,186}$Hg. An improvement on previously measured values of yrast states up to $8^{+}$ is presented as well as first values for the $9_{3}$ state in $^{184}$Hg and $10^{+}$ state in $^{186}$Hg. $B(E2)$ values are calculated and compared to a two-state mixing model which utilizes the variable moment of inertia (VMI) model, allowing for extraction of spin-dependent mixing strengths and amplitudes.

  5. Spinal Muscular Atrophy: From Defective Chaperoning of snRNP Assembly to Neuromuscular Dysfunction

    Directory of Open Access Journals (Sweden)

    Maia Lanfranco

    2017-06-01

    Full Text Available Spinal Muscular Atrophy (SMA is a neuromuscular disorder that results from decreased levels of the survival motor neuron (SMN protein. SMN is part of a multiprotein complex that also includes Gemins 2–8 and Unrip. The SMN-Gemins complex cooperates with the protein arginine methyltransferase 5 (PRMT5 complex, whose constituents include WD45, PRMT5 and pICln. Both complexes function as molecular chaperones, interacting with and assisting in the assembly of an Sm protein core onto small nuclear RNAs (snRNAs to generate small nuclear ribonucleoproteins (snRNPs, which are the operating components of the spliceosome. Molecular and structural studies have refined our knowledge of the key events taking place within the crowded environment of cells and the numerous precautions undertaken to ensure the faithful assembly of snRNPs. Nonetheless, it remains unclear whether a loss of chaperoning in snRNP assembly, considered as a “housekeeping” activity, is responsible for the selective neuromuscular phenotype in SMA. This review thus shines light on in vivo studies that point toward disturbances in snRNP assembly and the consequential transcriptome abnormalities as the primary drivers of the progressive neuromuscular degeneration underpinning the disease. Disruption of U1 snRNP or snRNP assembly factors other than SMN induces phenotypes that mirror aspects of SMN deficiency, and splicing defects, described in numerous SMA models, can lead to a DNA damage and stress response that compromises the survival of the motor system. Restoring the correct chaperoning of snRNP assembly is therefore predicted to enhance the benefit of SMA therapeutic modalities based on augmenting SMN expression.

  6. Isomer shifts and chemical bonding in crystalline Sn(II) and Sn(IV) compounds

    International Nuclear Information System (INIS)

    Terra, J.; Guenzburger, D.

    1991-01-01

    First-principles self-consistent Local Density calculations of the electronic structure of clusters representing Sn(II) (SnO, SnF 2 , SnS, SnSe) and Sn(IV) (SnO 2 , SnF 4 ) crystalline compounds were performed. Values of the electron density at the Sn nucleus were obtained and related to measured values of the Moessbauer Isomer Shifts reported in the literature. The nuclear parameter of 119 Sn derived was ΔR/R=(1.58±0.14)x10 -4 . The chemical bonding in the solids was analysed and related to the electron densities obtained. (author)

  7. Diffusion slowdown in the nanostructured liquid Ga-Sn alloy

    International Nuclear Information System (INIS)

    Podorozhkin, Dmitri Y.; Charnaya, Elena V.; Lee, Min Kai; Chang, Lieh-Jeng; Haase, Juergen; Michel, Dieter; Kumzerov, Yurii A.; Fokin, Alexsandr V.

    2015-01-01

    The diffusion of gallium in liquid Ga-Sn alloy embedded into different porous silica matrices was studied by NMR. Spin relaxation was measured for two gallium isotopes, 71 Ga and 69 Ga, at two magnetic fields. Pronounced rise of quadrupole contribution to relaxation was observed for the nanostructured alloy which increased with decreasing the pore size. The correlation time of atomic mobility was evaluated and found to be much larger than in the relevant bulk melt which evidenced a pronounced diffusion slowdown in the Ga-Sn alloy under nanoconfinement. It is shown that the diffusion was slower by a factor of 30 for the alloy within 7 nm pores. The spectral densities of electric field gradients at zero frequency were found to double for the finest pores. The Knight shift was found to decrease but slightly for the nanostructured alloy. (copyright 2015 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Selective Hydrogenation of m-Dinitrobenzene to m-Nitroaniline over Ru-SnOx/Al2O3 Catalyst

    Directory of Open Access Journals (Sweden)

    Haiyang Cheng

    2014-07-01

    Full Text Available Series catalysts of Ru-SnOx/Al2O3 with varying SnOx loading of 0–3 wt% were prepared, and their catalytic activity and selectivity have been discussed and compared for the selective hydrogenation of m-dinitrobenzene (m-DNB to m-nitroaniline (m-NAN. The Ru-SnOx/Al2O3 catalysts were characterized by X-ray powder diffraction (XRD, X-ray photoelectron spectroscopy (XPS, transmission electron microscopy (TEM and hydrogen temperature-programmed reduction (H2-TPR and desorption (H2-TPD. Under the modification of SnOx, the reaction activity increased obviously, and the best selectivity to m-NAN reached above 97% at the complete conversion of m-DNB. With the increasing of the SnOx loading, the amount of active hydrogen adsorption on the surface of the catalyst increased according to the H2-TPD analysis, and the electron transferred from Ru to SnOx species, as determined by XPS, inducing an electron-deficient Ru, which is a benefit for the absorption of the nitro group. Therefore, the reaction rate and product selectivity were greatly enhanced. Moreover, the Ru-SnOx/Al2O3 catalyst presented high stability: it could be recycled four times without any loss in activity and selectivity.

  9. Accelerator based Production of Auger-Electron-emitting Isotopes for Radionuclide Therapy

    DEFF Research Database (Denmark)

    Thisgaard, Helge

    Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron...... isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able...

  10. Decay of new mass-separated neutron-deficient La and Ce isotopes

    International Nuclear Information System (INIS)

    Genevey, J.; Gizon, A.; Idrissi, N.; Weiss, B.; Beraud, R.; Charvet, A.; Duffait, R.; Emsallem, A.; Meyer, M.; Ollivier, T.; Redon, N.

    1987-01-01

    By use of a He jet system coupled to a Bernas-Nier ion-source, several new mass-separated A = 122 - 127 isotopes reached in heavy ion fusion reactions at SARA have been identified and studied. From experimental decay properties of La isotopes, systematics of low-lying energy levels have been extended for even-even and odd-A barium. New informations on Ce decay schemes are briefly reported

  11. Development of 119Sn nuclear resonance scattering of synchrotron radiation and first applications

    International Nuclear Information System (INIS)

    Barla, A.

    2001-01-01

    In the framework of this thesis the NRS technique has been developed and applied, for the first time at the European Synchrotron Radiation Facility, at the resonance of 119 Sn. Elastic nuclear forward scattering (NFS) is ideal for studies of hyperfine interactions, where information about the electronic and magnetic properties of solids is obtained. On the other hand nuclear inelastic scattering (NIS) allows one to study the phonon density of states (DOS) of Moessbauer isotopes in various kinds of systems. In the first stage, technical developments have been made, particularly with regards the used optical elements. A key point has been the construction of a high resolution monochromator (HRM) for the resonance of 119 Sn, with an energy resolution of about 0.65 meV, perfectly suited to perform NIS experiments. A second HRM optimised in throughput has been constructed and used, in combination with focussing elements (bent crystals and compound refractive lenses), to perform NFS experiments at very high pressure. For the first applications of 119 Sn NIS, the phonon DOS of β-Sn has been directly determined from the NIS spectra measured at T = 100 K and T = 300 K. An excellent agreement has been found with the phonon DOS obtained theoretically by previous calculations. Moreover, dynamical and thermodynamical properties of β-Sn extracted from the determined DOS, such as the Lamb-Moessbauer factor and the specific heat, are found to be in good agreement with previously published results. As a first application of 119 Sn NFS experiments at high pressure, the system U(In 1-x Sn x ) 3 has been chosen. (orig.)

  12. Nuclear Spectroscopy with Copper Isotopes of Extreme N/Z Ratios

    CERN Multimedia

    La commara, M; Roeckl, E; Van duppen, P L E; Schmidt, K A; Lettry, J

    2002-01-01

    The collaboration aims to obtain detailed nuclear spectroscopy information on isotopes close to the magic proton number Z=28 Very neutron-rich and neutron-deficient copper isotopes are ionized with the ISOLDE resonance ionization laser ion source (RILIS) to provide beams with low cross contamination.\\\\ \\\\On the neutron-deficient side the high $Q_\\beta$-values of $^{56}$Cu (15~MeV) and $^{57}$Cu (8.8~MeV) allow to study levels at high excitation energies in the doubly magic nucleus $^{56}$Ni and the neighbouring $^{57}$Ni. On the neutron-rich side the spectroscopy with separated copper isotopes allows presently the closest approach to the doubly magic $^{78}$Ni at an ISOL facility. Up to now no suitable target material with a rapid release was found for nickel itself. A slow release behaviour has to be assumed also for the chemically similar elements iron and cobalt.\\\\ \\\\Using a narrow-bandwidth dye laser and tuning of the laser frequency allows to scan the hyperfine splittings of the copper isotopes and isome...

  13. States in 118Sn from 117Sn(d,p) 118Sn at 12 MeV

    International Nuclear Information System (INIS)

    Frota-Pessoa, E.

    1983-01-01

    118 Sn energy levels up to = 5.2 MeV excitation energy are studied in the reaction 117 Sn (d,p) 118 Sn. Deuterons had a bombarding energy of 12 MeV. The protons were analized by a magnetic spectrograph. The detector was nuclear emulsion and the resolution in energy about 10 KeV. The distorted-wave analysis was used to determine l values and spectroscopic strengths. Centers of gravity and the sums of reduced spectroscopic factors are presented for the levels when it was possible to determine the S' value. 66 levels of excitation energy were found which did not appear in previous 117 Sn (d,p) reactions. 40 levels were not found previously in any reaction giving 118 Sn. The results are compared with the known ones. (Author) [pt

  14. New techniques of laser spectroscopy on exotic isotopes of gallium and francium

    CERN Document Server

    Procter, Thomas John

    The neutron-deficient gallium isotopes down to ${N}$=32 have had their hyperfine structures and isotope shifts measured via collinear laser spectroscopy using the COLLAPS (COllinear LAser sPectroScopy) beam line. The ground-state spin of $^{63}$Ga has been determined as ${I}$ = 3/2 and its magnetic dipole and electric quadrupole moments were measured to be $\\mu$ = +1.469(5) $_{\\mu N}$ and ${ Q}$s = +0.212(14) b respectively. The nuclear moments of $^{70}$Ga were measured to be ${\\mu}$= +0.571(2) $_{\\mu}$ and ${Q}$s = +0.105(7) b. New isotope shift results were combined with previously measured values of the neutron-rich isotopes and the changes in mean-square charge radii of the entire gallium isotope chain were investigated. Analysis of the trend in the neutron-deficient charge radii demonstrated that there is no evidence of anomalous charge radii behaviour in gallium in the region of ${N}$=32. A sudden increase of the charge radii was observed at the ${N}$=50 shell gap and an inversion of the normal odd-eve...

  15. Uptake and metabolism of structured triglyceride by Caco-2 cells: reversal of essential fatty acid deficiency.

    Science.gov (United States)

    Spalinger, J H; Seidman, E G; Lepage, G; Ménard, D; Gavino, V; Levy, E

    1998-10-01

    Structured lipids have been proposed as efficient vehicles for the supplementation of essential fatty acids (EFA) to patients with malabsorption. We investigated how a novel structured triglyceride (STG), containing purely octanoic acid in the sn-1/sn-3 and [14C]linoleic acid in the sn-2 positions, was incorporated into different lipid classes in Caco-2 cells. We also evaluated the contribution of gastric lipase in the uptake and metabolism of [14C]linoleic acid from the STG. We furthermore determined the potential of the STG to correct EFA deficiency induced in Caco-2 cells. The absorption of STG by Caco-2 cells was significantly greater compared with that of triolein. The addition of human gastric lipase significantly enhanced cellular uptake of the labeled substrate, reflecting the stereoselectivity of gastric lipase to hydrolyze medium chain FA. Analysis of the intracellular lipids synthesized revealed a predominance of phospholipids-monoglycerides. Most of the radioactivity in the lipoproteins isolated from Caco-2 cells was recovered in TG-rich lipoproteins (45%) and to a lesser extent in the high-density lipoprotein (36%) and low-density lipoprotein (17%) fractions. The administration of STG to Caco-2 cells rendered EFA deficient produced a marked increase of the cellular level of linoleic and arachidonic acids. This resulted in a lower ratio of 20:3(n-9) to 20:4(n-6), reflecting the correction of EFA deficiency in Caco-2 cells. Our data demonstrate that STG, in the presence of gastric lipase, have beneficial effects on lipid incorporation, lipoprotein production, and EFA status, utilizing Caco-2 cells as a model of EFA deficiency.

  16. Effects of interlayer Sn-Sn lone pair interaction on the band gap of bulk and nanosheet SnO

    Science.gov (United States)

    Umezawa, Naoto; Zhou, Wei

    2015-03-01

    Effects of interlayer lone-pair interactions on the electronic structure of SnO are firstly explored by the density-functional theory. Our comprehensive study reveals that the band gap of SnO opens as increase in the interlayer Sn-Sn distance. The effect is rationalized by the character of band edges which consists of bonding and anti-bonding states from interlayer lone pair interactions. The band edges for several nanosheets and strained double-layer SnO are estimated. We conclude that the double-layer SnO is a promising material for visible-light driven photocatalyst for hydrogen evolution. This work is supported by the Japan Science and Technology Agency (JST) Precursory Research for Embryonic Science and Technology (PRESTO) program.

  17. Oxidation of Pb-Sn and Pb-Sn-In alloys

    International Nuclear Information System (INIS)

    Sluzewski, D.A.; Chang, Y.A.; Marcotte, V.C.

    1990-01-01

    Air oxidized Pb-Sn and Pb-Sn-In single phase alloys have been studied with scanning Auger microscopy. Line scans across grain boundaries combined with argon ion sputter etching revealed grain boundary oxidation. In the Pb-Sn samples, tin is preferentially oxidized with the grain boundary regions having a much higher percentage of tin oxide than the bulk surface oxide. In the Pb-Sn-In alloys, both tin and indium are preferentially oxidized with the grain boundary regions being enriched with tin and indium oxides

  18. Analyses of the Sn IX-Sn XII spectra in the EUV region

    International Nuclear Information System (INIS)

    Churilov, S S; Ryabtsev, A N

    2006-01-01

    The Sn IX-Sn XII spectra excited in a vacuum spark have been analysed in the 130-160 A wavelength region. The analysis was based on the energy parameter extrapolation in the isonuclear Sn VI-VIII and Sn XIII-XIV sequence. 266 spectral lines belonging to the 4d m -(4d m-1 4f+4p 5 4d m+1 ) (m=6-3) transition arrays were classified in the Sn IX-Sn XII spectra for the first time. All 18 level energies of the 4d 3 configuration and 39 level energies of the strongly interacting 4d 2 4f and 4p 5 4d 4 configurations were established in the Sn XII spectrum. The energy differences between the majority of the 4d m levels and about 40 levels of the 4d m-1 4f+4p 5 4d m+1 configurations were determined in each of the Sn IX, Sn X and Sn XI spectra (m=6-4). As a result, all intense lines were classified in the 130-140 A region relevant to the extreme ultraviolet (EUV) lithography. It was shown that the most of the intense lines in the 2% bandwidth at 135 A belong to the transitions in the Sn XI-Sn XIII spectra

  19. Rod-like hierarchical Sn/SnOx@C nanostructures with enhanced lithium storage properties

    Science.gov (United States)

    Yang, Juan; Chen, Sanmei; Tang, Jingjing; Tian, Hangyu; Bai, Tao; Zhou, Xiangyang

    2018-03-01

    Rod-like hierarchical Sn/SnOx@C nanostructures have been designed and synthesized via calcining resorcinol-formaldehyde (RF) resin coated Sn-based metal-organic frameworks. The rod-like hierarchical Sn/SnOx@C nanostructures are made of a great number of carbon-wrapped primary Sn/SnOx nanospheres of 100-200 nm in diameter. The as-prepared hierarchical Sn/SnOx@C nanocomposite manifests a high initial reversible capacity of 1177 mAh g-1 and remains 1001 mAh g-1 after 240 cycles at a current density of 200 mA g-1. It delivers outstanding high-rate performance with a reversible capacity of 823 mAh g-1 even at a high current density of 1000 mA g-1. The enhanced electrochemical performances of the Sn/SnOx@C electrode are mainly attributed to the synergistic effect of the unique hierarchical micro/nanostructures and the protective carbon layer.

  20. Precision Mass Measurement of Argon Isotopes

    CERN Multimedia

    Lunney, D

    2002-01-01

    % IS388\\\\ \\\\ A precision mass measurement of the neutron-deficient isotopes $^{32,33,34}$Ar is proposed. Mass values of these isotopes are of importance for: a) a stringent test of the Isobaric-Multiplet- Mass-Equation, b) a verification of the correctness of calculated charge-dependent corrections as used in super-allowed $\\beta$- decay studies aiming at a test of the CVC hypothesis, and c) the determination of the kinematics in electron-neutrino correlation experiments searching for scalar currents in weak interaction. The measurements will be carried out with the ISOLTRAP Penning trap mass spectrometer.

  1. Development of {sup 119}Sn nuclear resonance scattering of synchrotron radiation and first applications

    Energy Technology Data Exchange (ETDEWEB)

    Barla, A.

    2001-07-01

    In the framework of this thesis the NRS technique has been developed and applied, for the first time at the European Synchrotron Radiation Facility, at the resonance of {sup 119}Sn. Elastic nuclear forward scattering (NFS) is ideal for studies of hyperfine interactions, where information about the electronic and magnetic properties of solids is obtained. On the other hand nuclear inelastic scattering (NIS) allows one to study the phonon density of states (DOS) of Moessbauer isotopes in various kinds of systems. In the first stage, technical developments have been made, particularly with regards the used optical elements. A key point has been the construction of a high resolution monochromator (HRM) for the resonance of {sup 119}Sn, with an energy resolution of about 0.65 meV, perfectly suited to perform NIS experiments. A second HRM optimised in throughput has been constructed and used, in combination with focussing elements (bent crystals and compound refractive lenses), to perform NFS experiments at very high pressure. For the first applications of {sup 119}Sn NIS, the phonon DOS of {beta}-Sn has been directly determined from the NIS spectra measured at T = 100 K and T = 300 K. An excellent agreement has been found with the phonon DOS obtained theoretically by previous calculations. Moreover, dynamical and thermodynamical properties of {beta}-Sn extracted from the determined DOS, such as the Lamb-Moessbauer factor and the specific heat, are found to be in good agreement with previously published results. As a first application of {sup 119}Sn NFS experiments at high pressure, the system U(In{sub 1-x}Sn{sub x}){sub 3} has been chosen. (orig.)

  2. Synthesis, characterization and photocatalytic performance of SnS nanofibers and SnSe nanofibers derived from the electrospinning-made SnO{sub 2} nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Li; Li, Dan; Dong, Xiangting; Ma, Qianli; Yu, Wensheng; Wang, Xinlu; Yu, Hui; Wang, Jinxian; Liu, Guixia, E-mail: dongxiangting888@163.com [Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun (China)

    2017-11-15

    SnO{sub 2} nanofibers were fabricated by calcination of the electrospun PVP/SnCl{sub 4} composite nanofibers. For the first time, SnS nanofibers and SnSe nanofibers were successfully synthesized by double crucible sulfurization and selenidation methods via inheriting the morphology of SnO{sub 2} nanofibers used as precursors, respectively. X-ray diffraction (XRD) analysis shows SnS nanofibers and SnSe nanofibers are respectively pure orthorhombic phase with space group of Pbnm and Cmcm. Scanning electron microscope (SEM) observation indicates that the diameters of SnS nanofibers and SnSe nanofibers are respectively 140.54±12.80 nm and 96.52±14.17 nm under the 95 % confidence level. The photocatalytic activities of samples were studied by using rhodamine B (Rh B) as degradation agent. When SnS or SnSe nanofibers are employed as the photocatalysts, the respective degradation rates of Rh B solution under the ultraviolet light irradiation after 200 min irradiation are 92.55 % and 92.86 %. The photocatalytic mechanism and formation process of SnS and SnSe nanofibers are also provided. More importantly, this preparation technique is of universal significance to prepare other metal chalcogenides nanofibers. (author)

  3. The influence of magnesium deficiency on calcium metabolism in the rat

    International Nuclear Information System (INIS)

    Larvor, P.; Labat, M.-L.

    1978-01-01

    Calcium metabolism was studied in magnesium-deficient rats with an isotopic technique. 45 Ca was injected intravenously and the blood calcium radioactivity curve was analyzed mathematically to compute the kinetics of calcium exchange in the whole body. No important change was noticed after a 10-day magnesium deficiency; there was a significant reduction of the ratio calcium pool/total calcium output from the pool (P/Vsub(T)). After a 20-day deficiency, a dramatic decrease in the two compartments of exchangeable calcium (-40%), and a less important decrease of Vsub(T)(-15%) was noted. Blood plasma urea level increased during magnesium deficiency, while urea urinary clearance remained

  4. Sn-In-Ag phase equilibria and Sn-In-(Ag)/Ag interfacial reactions

    International Nuclear Information System (INIS)

    Chen Sinnwen; Lee Wanyu; Hsu Chiaming; Yang Chingfeng; Hsu Hsinyun; Wu Hsinjay

    2011-01-01

    Research highlights: → Thermodynamic models of Sn-In and Sn-In-Ag are developed using the CALPHAD approach. → Reaction layer in the Sn-In-(Ag)/Ag couples at 100 deg. C is thinner than those at 25 deg. C, 50 deg. C, and 75 deg. C. → Reactions in the Sn-20 wt%In-2.8 wt%Ag/Ag couples are faster than those in the Sn-20 wt%In/Ag couples. - Abstract: Experimental verifications of the Sn-In and Sn-In-Ag phase equilibria have been conducted. The experimental measurements of phase equilibria and thermodynamic properties are used for thermodynamic modeling by the CALPHAD approach. The calculated results are in good agreement with experimental results. Interfacial reactions in the Sn-In-(Ag)/Ag couples have been examined. Both Ag 2 In and AgIn 2 phases are formed in the Sn-51.0 wt%In/Ag couples reacted at 100 and 150 deg. C, and only the Ag 2 In phase is formed when reacted at 25, 50 and 75 deg. C. Due to the different growth rates of different reaction phases, the reaction layer at 100 deg. C is thinner than those at 25 deg. C, 50 deg. C, and 75 deg. C. In the Sn-20.0 wt%In/Ag couples, the ζ phase is formed at 250 deg. C and ζ/AgIn 2 phases are formed at 125 deg. C. Compared with the Sn-20 wt%In/Ag couples, faster interfacial reactions are observed in the Sn-20.0 wt%In-2.8 wt%Ag/Ag couples, and minor Ag addition to Sn-20 wt%In solder increases the growth rates of the reaction phases.

  5. Magnetic behaviour of cerium in Ce2 Sn5 and Ce3 Sn7, surstructures of Ce Sn3

    International Nuclear Information System (INIS)

    Stunault, A.

    1988-07-01

    The compound studied, Ce 2 Sn 5 and Ce 3 Sn 7 are both orthorhombic, surstructure of cubic Ce Sn 3 . Magnetic susceptibility measurements show in both compounds an antiferromagnetic order at low temperature and magnetization shows a high anisotropy. Magnetization densities are determined by polarized neutron diffraction. The cerium site which has two Ce atoms as nearest neighbourgs carries all the magnetism in both structures. For Ce 2 Sn 5 moments are directed as the high magnetization axis and structure is modulated. Ce 3 Sn 7 presents a simple antiferromagnetic order but moment are directed as low magnetization axis. Various transitions towards a ferromagnetic order are presented. Results are interpreted by measuring the difference between energy levels of crystalline field. A model of crystalline field and isotrope exchange agrees well with Ce 3 Sn 7 , but for Ce 2 Sn 7 it is necessary to reduce the magnetic moment which is typical of the Kondo effect [fr

  6. Cold fusion valleys for the synthesis of Z=118 isotopes

    International Nuclear Information System (INIS)

    Gherghescu, R.

    2005-01-01

    Cold fusion reactions are investigated with the goal to synthesize Z=118 isotopes with neutron numbers N=162, 168, 172, 176. Potential energy surfaces are calculated as the result of dynamic minimization with independent deformations of the target and projectile, small semi-axis of the projectile and distance between centers as degrees of freedom. An advanced binary macroscopic-microscopic method is used to obtain the deformation energy and the Werner-Wheeler approximation yield the mass tensor. Charge asymmetry is varied for the same mass asymmetry channel which belongs to a given energy valley. The highest penetrability values are obtained for cold fusion channels with Sn, Te and Xe isotopes as projectiles

  7. Isotope production

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Dewi M.

    1995-07-15

    Some 2 0% of patients using radiopharmaceuticals receive injections of materials produced by cyclotrons. There are over 200 cyclotrons worldwide; around 35 are operated by commercial companies solely for the production of radio-pharmaceuticals with another 25 accelerators producing medically useful isotopes. These neutron-deficient isotopes are usually produced by proton bombardment. All commonly used medical isotopes can be generated by 'compact' cyclotrons with energies up to 40 MeV and beam intensities in the range 50 to 400 microamps. Specially designed target systems contain gram-quantities of highly enriched stable isotopes as starting materials. The targets can accommodate the high power densities of the proton beams and are designed for automated remote handling. The complete manufacturing cycle includes large-scale target production, isotope generation by cyclotron beam bombardment, radio-chemical extraction, pharmaceutical dispensing, raw material recovery, and labelling/packaging prior to the rapid delivery of these short-lived products. All these manufacturing steps adhere to the pharmaceutical industry standards of Good Manufacturing Practice (GMP). Unlike research accelerators, commercial cyclotrons are customized 'compact' machines usually supplied by specialist companies such as IBA (Belgium), EBCO (Canada) or Scanditronix (Sweden). The design criteria for these commercial cyclotrons are - small magnet dimensions, power-efficient operation of magnet and radiofrequency systems, high intensity extracted proton beams, well defined beam size and automated computer control. Performance requirements include rapid startup and shutdown, high reliability to support the daily production of short-lived isotopes and low maintenance to minimize the radiation dose to personnel. In 1987 a major step forward in meeting these exacting industrial requirements came when IBA, together with the University of Louvain-La-Neuve in Belgium, developed the Cyclone-30

  8. Laser Spectroscopy of Neutron Rich Bismuth Isotopes

    CERN Multimedia

    2002-01-01

    %IS344 :\\\\ \\\\ The aim of the experiment is to measure the optical isotope shifts and hyperfine structures of bismuth isotopes across the N=126 shell closure in order to extract the change in mean square charge radii ($\\delta\\langle r^{2}\\rangle$) and static moments. These include the first isotones of lead to be measured directly above the shell closure and will provide new information on the systematics of the kink ($\\delta\\langle r^{2}\\rangle)$ seen in the lead isotopic chain. After two very successful runs the programme has been extended to include the neutron deficient isotopes below $^{201}$Bi to study the systematics across the $i_{13/2}$ neutron sub-shell closure at N=118.\\\\ \\\\ During the initial 2 runs (9 shifts) the isotope shifts and hyperfine structures of three new isotopes, $ ^{210,212,213}$Bi and the 9$^{-}$ isomer of $^{210}$Bi have been measured. The accuracy of the previous measurements of $^{205,206,208}$Bi have been greatly improved. The samples of $ ^{208,210,210^{m}}$Bi were prepared by c...

  9. Electrical, optical and etching properties of Zn-Sn-O thin films deposited by combinatorial sputtering

    International Nuclear Information System (INIS)

    Kim, J. S.; Park, J. K.; Baik, Y. J.; Kim, W. M.; Jeong, J.; Seong, T. Y.

    2012-01-01

    Zn-Sn-O (ZTO) films are known to be able to form an amorphous phase, which provides a smooth surface morphology as well as etched side wall, when deposited by using the conventional sputtering technique and, therefore, to have a potential to be applied as transparent thin film transistors. In this study, ZTO thin films were prepared by using combined sputtering of ZnO and SnO 2 targets, and the dependences of their electrical and optical properties on the composition and the deposition parameters were examined. The Sn content in the films was varied in the range of 35 ∼ 85 at .%. The deposition was carried out at room temperature, 150 and 300 .deg. C, and the oxygen content in sputtering gas was varied from 0 to 1 vol.%. Sn-rich films had better electrical properties, but showed large oxygen deficiency when deposited at low oxygen partial pressures. ZTO films with Sn contents lower than 55 at.% had good optical transmission, but the electrical properties were poor due to very low carrier concentrations. A high Hall mobility of larger than 10 cm 2 /Vs could be obtained in the carrier density range 10 17 ∼ 10 20 cm -3 , and the etching rate was measurable for films with Sn content up to 70 at.% when using a dilute HCl solution, indicating a good possibility of utilizing ZTO films for device applications.

  10. Ethanol electrooxidation on Pt-Sn and Pt-Sn-W bulk alloys

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, D.M. dos; Hahn, F.; Leger, J.M.; Kokoh, K.B. [Universite de Poitiers, Poitiers Cedex (France). Centre National de la Recherche Scientifique (CNRS). Equipe Electrocatalyse; Tremiliosi-Filho, G. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica

    2008-07-01

    Ethanol oxidation has been studied on Pt-Sn and Pt-Sn-W electrodes prepared in an arc-melting furnace. Different electrochemical techniques like cyclic voltammetry and chronoamperometry were used to evaluate the catalytic activity of these materials. The electro-oxidation process was also investigated by in situ infrared reflectance spectroscopy in order to determine adsorbed intermediates and reaction products. Experimental results indicated that Pt-Sn and Pt-Sn-W alloys are able to oxidize ethanol mainly to acetaldehyde and acetic acid. Adsorbed CO was also detected, demonstrating the viability of splitting the C-C bond in the ethanol molecule during the oxidation process. The adsorbed CO was further oxidized to CO{sub 2}.This reaction product was clearly detected by SNIFTIRS. Pt-Sn-W catalyst showed a better electrochemical performance than Pt-Sn that, in it turn, is better than Pt-alone. (author)

  11. Ultraviolet emission from low resistance Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires

    Directory of Open Access Journals (Sweden)

    E. Karageorgou

    2014-11-01

    Full Text Available SnO2 and Sn:In2O3 nanowires were grown on Si(001, and p-n junctions were fabricated in contact with p-type Cu2S which exhibited rectifying current–voltage characteristics. Core-shell Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires were obtained by depositing copper and post-growth processing under H2S between 100 and 500 °C. These consist mainly of tetragonal rutile SnO2 and cubic bixbyite In2O3. We observe photoluminescence at 3.65 eV corresponding to band edge emission from SnO2 quantum dots in the Cu2SnS3/SnO2 nanowires due to electrostatic confinement. The Cu2SnS3/SnO2 nanowires assemblies had resistances of 100 Ω similar to CuInS2/In2O3 nanowires which exhibited photoluminescence at 3.0 eV.

  12. Phase diagram of SnTe-CdSe cross-section of SnTe+CdSe reversible SnSe+CdTe ternary reciprocal system

    International Nuclear Information System (INIS)

    Dubrovin, I.V.; Budennaya, L.D.; Mizetskaya, I.B.; Sharkina, Eh.V.

    1986-01-01

    Phase equilibrium diagram of SnTe-CdSe cross-section of Sn, Cd long Te, Se ternary reciprocal system is investigated using the methods of differential thermal, X-ray phase, and microstructural analyses. Maximum length of solid solutions on the base of SnTe corresponds to approximately 14 mol.% at 1050 K and approximately 3 mol.% of CdSe at 670 K. Region of solid solutions on the base of CdSe corresponds to less than 1 mol.% of SnTe at room temperature. SnTe-CdSe cross-section is not a quasibinar one. Equilibrium is shifted to the left in the SnTe+CdSe reversible SnSe+CdTe reciprocal system

  13. Structure of excited states in nuclei near doubly magic {sup 100}SN

    Energy Technology Data Exchange (ETDEWEB)

    Gorska, M.

    1998-11-01

    The three neutron-deficient nuclei {sup 94}Pd, {sup 98}Cd and {sup 104}Sn in the vicinity of {sup 100}Sn were investigated by means of in-beam {gamma}-ray spectroscopy of excited states. The isomeric decays in {sup 94}Pd and {sup 98}Cd were studied for the first time with an exclusive experimental setup for delayed {gamma}-ray detection with complete exit channel identification based on information from neutron and charged-particle filter detectors. The structure of excited states of {sup 94}Pd showed the first indication of increasing proton-neutron interaction towards the N=Z line in this region of nuclei, that in turn might be related to increased proton-neutron pairing correlations predicted in T{sub z}=0 nuclei. The closest neighbours of {sup 100}Sn with two active particles, {sup 98}Cd and {sup 102}Sn, are now known with their lowest excited states. The measured reduced transition probabilities for the decay of the isomeric 8{sup +} and 6{sup +} states in {sup 98}Cd and {sup 102}Sn, respectively, allowed to extract an effective quadrupole charge for neutron and proton in this region of nuclei based on the high configurational purity of the states. While the neutron effective charge appeared to be large and in agreement with expectation, the proton effective charge value is very small (e{sub {pi}}{<=}1). This controversial result, which would indicate that {sup 100}Sn is a very good closed shell nucleus with respect to quadrupole excitation, is not understood. An experimental reason for this result, related to existence of a core excited isomer, observed in the experiment by means of its half life but not {gamma}-rays, which may have escaped observation, can not be definitely excluded and is left as possible explanation. (orig.)

  14. The pygmy quadrupole resonance and neutron-skin modes in 124Sn

    Directory of Open Access Journals (Sweden)

    M. Spieker

    2016-01-01

    Full Text Available We present an extensive experimental study of the recently predicted pygmy quadrupole resonance (PQR in Sn isotopes, where complementary probes were used. In this study, (α,α′γ and (γ,γ′ experiments were performed on 124Sn. In both reactions, Jπ=2+ states below an excitation energy of 5 MeV were populated. The E2 strength integrated over the full transition densities could be extracted from the (γ,γ′ experiment, while the (α,α′γ experiment at the chosen kinematics strongly favors the excitation of surface modes because of the strong α-particle absorption in the nuclear interior. The excitation of such modes is in accordance with the quadrupole-type oscillation of the neutron skin predicted by a microscopic approach based on self-consistent density functional theory and the quasiparticle-phonon model (QPM. The newly determined γ-decay branching ratios hint at a non-statistical character of the E2 strength, as it has also been recently pointed out for the case of the pygmy dipole resonance (PDR. This allows us to distinguish between PQR-type and multiphonon excitations and, consequently, supports the recent first experimental indications of a PQR in 124Sn.

  15. Ion microscopic imaging of calcium transport in the intestinal tissue of vitamin D-deficient and vitamin D-replete chickens: A 44Ca stable isotope study

    International Nuclear Information System (INIS)

    Chandra, S.; Fullmer, C.S.; Smith, C.A.; Wasserman, R.H.; Morrison, G.H.

    1990-01-01

    The intestinal absorption of calcium includes at least three definable steps; transfer across the microvillar membrane, movement through the cytosolic compartment, and energy-dependent extrusion into the lamina propria, Tracing the movement of calcium through the epithelium has been hampered by lack of suitable techniques and, in this study, advantage was taken of ion microscopy in conjunction with cryosectioning and use of the stable isotope 44Ca to visualize calcium in transit during the absorptive process. The effect of vitamin D, required for optimal calcium absorption, was investigated. Twenty millimolar 44Ca was injected into the duodenal lumen in situ of vitamin D-deficient and vitamin D-replete chickens. At 2.5, 5.0, and 20.0 min after injection, duodenal tissue was obtained and processed for ion microscopic imaging. At 2.5 min. 44Ca was seen to be concentrated in the region subjacent to the microvillar membrane in tissue from both groups. At 5.0 and 20.0 min, a similar pattern of localization was evident in D-deficient tissues. In D-replete tissues, the distribution of 44Ca became more homogenous, indicating that vitamin D increased the rate of transfer of Ca2+ from the apical to the basolateral membrane, a function previously ascribed to the vitamin D-induced calcium-binding protein (28-kDa calbindin-D). Quantitative aspects of the calcium absorptive process were determined in parallel experiments with the radionuclide 47Ca. Complementary information on the localization of the naturally occurring isotopes of calcium (40Ca) and potassium (39K) is also described

  16. 70 °C synthesis of high-Sn content (25%) GeSn on insulator by Sn-induced crystallization of amorphous Ge

    Energy Technology Data Exchange (ETDEWEB)

    Toko, K., E-mail: toko@bk.tsukuba.ac.jp; Oya, N.; Suemasu, T. [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Saitoh, N.; Yoshizawa, N. [Electron Microscope Facility, TIA, AIST, 16-1 Onogawa, Tsukuba 305-8569 (Japan)

    2015-02-23

    Polycrystalline GeSn thin films are fabricated on insulating substrates at low temperatures by using Sn-induced crystallization of amorphous Ge (a-Ge). The Sn layer stacked on the a-Ge layer (100-nm thickness each) had two roles: lowering the crystallization temperature of a-Ge and composing GeSn. Slow annealing at an extremely low temperature of 70 °C allowed for a large-grained (350 nm) GeSn layer with a lattice constant of 0.590 nm, corresponding to a Sn composition exceeding 25%. The present investigation paves the way for advanced electronic optical devices integrated on a flexible plastic substrate as well as on a Si platform.

  17. Controlling the antibacterial activity of CuSn thin films by varying the contents of Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yujin; Park, Juyun; Kim, Dong-Woo; Kim, Hakjun; Kang, Yong-Cheol, E-mail: yckang@pknu.ac.kr

    2016-12-15

    Highlights: • We deposit CuSn thin films on a Si substrate with various Cu/Sn ratio. • Antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time increased. • XPS was utilized to assign the chemical environment of CuSn thin films before and after antibacterial test. - Abstract: We investigated antibacterial activity of CuSn thin films against Gram positive Staphylococcus aureus (S. aureus). CuSn thin films with different Cu to Sn ratios were deposited on Si(100) by radio frequency (RF) magnetron sputtering method using Cu and Sn metal anodes. The film thickness was fixed at 200 nm by varying the sputtering time and RF power on the metal targets. The antibacterial test was conducted in various conditions such as different contact times and Cu to Sn ratios in the CuSn films. The antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time between the film and bacteria suspension increased execpt in the case of CuSn-83. The oxidation states of Cu and Sn and the chemical composition of CuSn thin films before and after the antibacterial test were investigated by X-ray photoelectron spectroscopy (XPS). When the contact time was fixed, the Cu species was further oxidized as the RF power on Cu target increased. The intensity of Sn 3d decreased with increasing Cu ratio. When the sample was fixed, the peak intensity of Sn 3d decreased as the contact time increased due to the permeation of Sn into the cell.

  18. Spectral and ion emission features of laser-produced Sn and SnO2 plasmas

    Science.gov (United States)

    Hui, Lan; Xin-Bing, Wang; Du-Luo, Zuo

    2016-03-01

    We have made a detailed comparison of the atomic and ionic debris, as well as the emission features of Sn and SnO2 plasmas under identical experimental conditions. Planar slabs of pure metal Sn and ceramic SnO2 are irradiated with 1.06 μm, 8 ns Nd:YAG laser pulses. Fast photography employing an intensified charge coupled device (ICCD), optical emission spectroscopy (OES), and optical time of flight emission spectroscopy are used as diagnostic tools. Our results show that the Sn plasma provides a higher extreme ultraviolet (EUV) conversion efficiency (CE) than the SnO2 plasma. However, the kinetic energies of Sn ions are relatively low compared with those of SnO2. OES studies show that the Sn plasma parameters (electron temperature and density) are lower compared to those of the SnO2 plasma. Furthermore, we also give the effects of the vacuum degree and the laser pulse energy on the plasma parameters. Project supported by the National Natural Science Foundation of China (Grant No. 11304235) and the Director Fund of WNLO, China.

  19. Fabrication of textured SnO2 transparent conductive films using self-assembled Sn nanospheres

    Science.gov (United States)

    Fukumoto, Michitaka; Nakao, Shoichiro; Hirose, Yasushi; Hasegawa, Tetsuya

    2018-06-01

    We present a novel method to fabricate textured surfaces on transparent conductive SnO2 films by processing substrates through a bottom-up technique with potential for industrially scalable production. The substrate processing consists of three steps: deposition of precursor Sn films on glass substrates, formation of a self-assembled Sn nanosphere layer with reductive annealing, and conversion of Sn to SnO2 by oxidative annealing. Ta-doped SnO2 films conformally deposited on the self-assembled nanospherical SnO2 templates exhibited attractive optical and electrical properties, namely, enhanced haze values and low sheet resistances, for applications as transparent electrodes in photovoltaics.

  20. Ordered CoSn-type ternary phases in Co3Sn3-xGex

    DEFF Research Database (Denmark)

    Allred, Jared M.; Jia, Shuang; Bremholm, Martin

    2012-01-01

    . By taking advantage of the chemical differences between the two crystallographically inequivalent Sn sites in the structure, we observe ordered ternary phases, nominally Co3SnGe2 and Co3Sn2Ge. The electron count and unit cell configuration remain unchanged from CoSn; these observations thus help to clarify...

  1. Beta-transition properties for neutron-rich Sn and Te isotopes by ...

    Indian Academy of Sciences (India)

    bour odd–odd nuclei and the β decay log(ft) values have been calculated within the framework of RPA. These calculations have been done for. 128,130,132. Sb and. 132,134,136. I isotopes. Since there is no study based on other models for the investi- gated nuclei in literature the calculations based on schematic model in ...

  2. A target concept for intense radioactive beams in the 132Sn Region

    International Nuclear Information System (INIS)

    Nolen, J.A. Jr.

    1993-01-01

    To produce intense secondary beams of radioactive isotopes, primary beams of up to 100 kW are being proposed at some facilities. There are plans to test production targets with 800 MeV protons at such higher power at the Rutherford Appleton Laboratory. In this paper the use of high energy neutrons as a possible alternative is presented. The concept is to generate an intense beam of neutrons in a well-cooled target with a primary deuteron beam. The neutrons have a high cross section for producing fission fragments in a thick uranium target which is coupled to the ion source for the secondary beams. The effective target thickness is large and the power dissipated in the ISOL target is relatively small, which should lead to intense beams of neutron-rich, intermediate-mass isotopes such as 132 Sn

  3. Site occupancy, composition and magnetic structure dependencies of martensitic transformation in Mn2Ni1+xSn1-x.

    Science.gov (United States)

    Kundu, Ashis; Ghosh, Subhradip

    2017-11-14

    A delicate balance between various factors such as site occupancy, composition and magnetic ordering seems to affect the stability of the martensitic phase in Mn2Ni1+xSn1-x. Using first-principles DFT calculations, we explore the impacts of each one of these factors on the martensitic stability of this system. Our results on total energies, magnetic moments and electronic structures upon changes in the composition, the magnetic configurations and the site occupancies show that the occupancies at the 4d sites in the Inverse Heusler crystal structure play the most crucial role. The presence of Mn at the 4d sites originally occupied by Sn and its interaction with the Mn atoms at other sites decide the stability of the martensitic phases. This explains the discrepancy between the experiments and earlier DFT calculations regarding phase stability in Mn2NiSn. Our results qualitatively explain the trends observed experimentally with regard to martensitic phase stability and the magnetisations in Ni-excess, Sn-deficient Mn2NiSn system. © 2017 IOP Publishing Ltd.

  4. Growth of highly textured SnS on mica using an SnSe buffer layer

    International Nuclear Information System (INIS)

    Wang, S.F.; Fong, W.K.; Wang, W.; Surya, C.

    2014-01-01

    We report the growth of SnS thin films on mica substrates by molecular beam epitaxy. Excellent 2D layered structure and strong (001) texture were observed with a record low rocking curve full width at half maximum of ∼ 0.101° for the SnS(004) diffraction. An interface model is used to investigate the nucleation of SnS on mica which indicates the co-existence of six pairs of lateral growth orientations and is in excellent agreement with the experimental Φ-scan measurements indicating 12 peaks separated by 30° from each other. To control the lateral growth of the SnS epilayers we investigate the utilization of a thin SnSe buffer layer deposited on the mica substrate prior to the growth of the SnS thin film. The excellent lattice match between SnSe and mica enhances the alignment of the nucleation of SnS and suppresses the minor lateral orientations along the mica[110] direction and its orthogonal axis. Detailed low-frequency noise measurement was performed to characterize the trap density in the films and our results clearly demonstrate substantial reduction in the density of the localized states in the SnS epilayer with the use of an SnSe buffer layer. - Highlights: • A record low rocking curve FWHM for deposited SnS on mica • Investigation of the nucleation of SnS on mica using the interface model • Investigation of nucleation mechanism by phi-scan measurement • Grain boundary formation from crystallites of various nucleation orientations • Suppression of nucleation orientations using an SnSe buffer layer

  5. A history of violence: Insights into post-accretionary heating in carbonaceous chondrites from volatile element abundances, Zn isotopes and water contents

    Science.gov (United States)

    Mahan, Brandon; Moynier, Frédéric; Beck, Pierre; Pringle, Emily A.; Siebert, Julien

    2018-01-01

    Carbonaceous chondrites (CCs) may have been the carriers of water, volatile and moderately volatile elements to Earth. Investigating the abundances of these elements, their relative volatility, and isotopes of state-change tracer elements such as Zn, and linking these observations to water contents, provide vital information on the processes that govern the abundances and isotopic signatures of these species in CCs and other planetary bodies. Here we report Zn isotopic data for 28 CCs (20 CM, 6 CR, 1 C2-ung, and 1 CV3), as well as trace element data for Zn, In, Sn, Tl, Pb, and Bi in 16 samples (8 CM, 6 CR, 1 C2-ung, and 1 CV3), that display a range of elemental abundances from case-normative to intensely depleted. We use these data, water content data from literature and Zn isotopes to investigate volatile depletions and to discern between closed and open system heating. Trace element data have been used to construct relative volatility scales among the elements for the CM and CR chondrites. From least volatile to most, the scale in CM chondrites is Pb-Sn-Bi-In-Zn-Tl, and for CR chondrites it is Tl-Zn-Sn-Pb-Bi-In. These observations suggest that heated CM and CR chondrites underwent volatile loss under different conditions to one another and to that of the solar nebula, e.g. differing oxygen fugacities. Furthermore, the most water and volatile depleted samples are highly enriched in the heavy isotopes of Zn. Taken together, these lines of evidence strongly indicate that heated CM and CR chondrites incurred open system heating, stripping them of water and volatiles concomitantly, during post-accretionary shock impact(s).

  6. Analysis of stable isotope data to estimate vitamin A body stores

    International Nuclear Information System (INIS)

    2008-06-01

    Vitamin A deficiency (VAD) is a serious public health problem in most developing countries. Because of the detrimental effects of vitamin A deficiency on human health, accurate assessment of vitamin A status is necessary to develop and evaluate intervention programmes. The IAEA is providing technical support to its Member States to use stable isotope dilution techniques to develop and evaluate programmes aimed at reducing vitamin A deficiency in populations. The stable isotope dilution technique, in contrast to other methods, have the potential to provide a quantitative estimate of vitamin A concentration across the continuum of status, from deficient to excess vitamin A body stores. In 2004 the IAEA, the United States Agency for International Development (USAID) and HarvestPlus initiated the Vitamin A Tracer Task Force, made up of international experts. HarvestPlus is a Global Challenge Program of the Consultative Group on International Agricultural Research (CGIAR). It is coordinated by the Centro Internacional de Agricultura Tropical (CIAT), a not-for-profit organization that conducts socially and environmentally progressive research aimed at reducing hunger and poverty and preserving natural resources in developing countries, located in Colombia, and the International Food Policy Research Institute (IFPRI), located in the United States of America and whose mission is to provide policy solutions aimed at reducing hunger and malnutrition in developing countries. The role of the Vitamin A Tracer Task Force was to prepare three complementary publications on the use of stable isotope dilution techniques to assess vitamin A body stores. The first publication entitled 'Appropriate Use of Vitamin A Tracer (Stable Isotope) Methodology' was published in 2004 by USAID/International Life Sciences Institute (ILSI) through the Micronutrient Global Leadership (MGL) project with co-sponsorship of IAEA and HarvestPlus. The second handbook is on 'Vitamin A Tracer Dilution

  7. Direct mass measurements of neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer

    International Nuclear Information System (INIS)

    Dilling, J.; Audi, G.; Beck, D.; Bollen, G.; Henry, S.; Herfurth, F.; Kellerbauer, A.; Kluge, H.-J.; Lunney, D.; Moore, R.B.; Scheidenberger, C.; Schwarz, S.; Sikler, G.; Szerypo, J.

    2002-01-01

    The masses of Xe isotopes with 124≥A≥114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500 000 was chosen resulting in an accuracy of δm∼12 keV for all isotopes investigated. Conflicts with existing mass data of several standard deviations were found

  8. Generic origin of subgap states in transparent amorphous semiconductor oxides illustrated for the cases of In-Zn-O and In-Sn-O

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, Wolfgang; Urban, Daniel F.; Elsaesser, Christian [Fraunhofer Institute for Mechanics of Materials IWM, Woehlerstr. 11, 79108, Freiburg (Germany)

    2015-07-15

    We present a microscopic interpretation for the appearance and behaviour of subgap states in stoichiometric and oxygen-deficient, amorphous In-Zn-O (a-IZO) and In-Sn-O (a-ITO) derived from a density functional theory analysis using a self-interaction-correction scheme. Our findings concerning the defect structures and the resulting deep levels are qualitatively similar to earlier results on a-IGZO and a-ZTO and in agreement with recent experimental results. Based on our extensive set of DFT results for In-, Sn-, Zn- based oxides we develop a general concept of the subgap states which is applicable to these systems. Electronic defect levels in the lower half of the band gap are created by undercoordinated oxygen atoms while local oxygen deficiencies cause defect levels in the upper part of the band gap. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Generic origin of subgap states in transparent amorphous semiconductor oxides illustrated for the cases of In-Zn-O and In-Sn-O

    International Nuclear Information System (INIS)

    Koerner, Wolfgang; Urban, Daniel F.; Elsaesser, Christian

    2015-01-01

    We present a microscopic interpretation for the appearance and behaviour of subgap states in stoichiometric and oxygen-deficient, amorphous In-Zn-O (a-IZO) and In-Sn-O (a-ITO) derived from a density functional theory analysis using a self-interaction-correction scheme. Our findings concerning the defect structures and the resulting deep levels are qualitatively similar to earlier results on a-IGZO and a-ZTO and in agreement with recent experimental results. Based on our extensive set of DFT results for In-, Sn-, Zn- based oxides we develop a general concept of the subgap states which is applicable to these systems. Electronic defect levels in the lower half of the band gap are created by undercoordinated oxygen atoms while local oxygen deficiencies cause defect levels in the upper part of the band gap. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Comparison of GC-ICP-MS and HPLC-ICP-MS for species-specific isotope dilution analysis of tributyltin in sediment after accelerated solvent extraction

    International Nuclear Information System (INIS)

    Wahlen, Raimund; Wolff-Briche, Celine

    2003-01-01

    This study describes a direct comparison of GC and HPLC hyphenated to ICP-MS determination of tributyltin (TBT) in sediment by species-specific isotope dilution analysis (SS-IDMS). The certified reference sediment PACS-2 (NRC, Canada) and a candidate reference sediment (P-18/HIPA-1) were extracted using an accelerated solvent extraction (ASE) procedure. For comparison of GC and LC methods an older bottle of PACS-2 was used, whilst a fresh bottle was taken for demonstration of the accuracy of the methods. The data obtained show good agreement between both methods for both the PACS-2 sediment (LC-ICP-IDMS 828±87 ng g -1 TBT as Sn, GC-ICP-IDMS 848±39 ng g -1 TBT as Sn) and the P-18/ HIPA-1 sediment (LC-ICP-IDMS 78.0±9.7 ng g -1 TBT as Sn, GC-ICP-IDMS 79.2±3.8 ng g -1 TBT as Sn). The analysis by GC-ICP-IDMS offers a greater signal-to-noise ratio and hence a superior detection limit of 0.03 pg TBT as Sn, in the sediment extracts compared to HPLC-ICP-IDMS (3 pg TBT as Sn). A comparison of the uncertainties associated with both methods indicates superior precision of the GC approach. This is related to the better reproducibility of the peak integration, which affects the isotope ratio measurements used for IDMS. The accuracy of the ASE method combined with HPLC-ICP-IDMS was demonstrated during the international interlaboratory comparison P-18 organised by the Comite Consultatif pour la Quantite de Matiere (CCQM). The results obtained by GC-ICP-IDMS for a newly opened bottle of PACS-2 were 1087±77 ng g -1 Sn for DBT and 876±51 ng g -1 Sn for TBT (expanded uncertainties with a coverage factor of 2), which are in good agreement with the certified values of 1090±150 ng g -1 Sn and 980±130 ng g -1 Sn, respectively. (orig.)

  11. Electrical and optical properties of SnEuTe and SnSrTe films

    Science.gov (United States)

    Ishida, Akihiro; Tsuchiya, Takuro; Yamada, Tomohiro; Cao, Daoshe; Takaoka, Sadao; Rahim, Mohamed; Felder, Ferdinand; Zogg, Hans

    2010-06-01

    The SnTe, Sn1-xEuxTe and Sn1-xSrxTe (x<0.06) films were prepared by hot wall epitaxy. The ternary alloy films prepared in cation rich condition had hole concentration around 1×1019 cm-3 with high mobility exceeding 2000 cm2/V s at room temperature. Optical transmission spectra were also measured in the temperature range from 100 to 400 K and compared with theoretical calculations. Optical transmission spectra of the SnTe were simulated successfully assuming bumped band edge structures. A band inversion model was proposed for the Sn1-xEuxTe and Sn1-xSrxTe systems, and the optical transmission spectra were also simulated successfully assuming the band inversion model.

  12. Hyperglucagonemia during insulin deficiency accelerates protein catabolism

    International Nuclear Information System (INIS)

    Nair, K.S.; Halliday, D.; Matthews, D.E.; Welle, S.L.

    1987-01-01

    Hyperglucagonemia coexists with insulin deficiency or insulin resistance in many conditions where urinary nitrogen excretion is increased, but the precise role of glucagon in these conditions is controversial. The purpose of this study was to evaluate the effect of hyperglucagonemia on protein metabolism in insulin-deficient subjects. The authors used the stable isotope of an essential amino acid (L-[1- 13 C]leucine) as a tracer of in vivo protein metabolism. A combined deficiency of insulin and glucagon was induced by intravenous infusion of somatostatin. Hyperglucagonemia and hypoinsulinemia were induced by infusions of somatostatin and glucagon. When somatostatin alone was infused leucine flux increased, indicating a 6-17% increase in proteolysis. When somatostatin and glucagon were infused, leucine flux increased, indicating a 12-32% increase in proteolysis. The increase in leucine flux during the infusion of somatostatin and glucagon was higher than the increase during infusion of somatostatin alone. Somatostatin alone did not change leucine oxidation, whereas the somatostatin plus glucagon increased leucine oxidation 100%. They conclude that hyperglucagonemia accelerated proteolysis and leucine oxidation in insulin-deficient humans

  13. Distribution and reuse of 76Se-selenosugar in selenium-deficient rats

    International Nuclear Information System (INIS)

    Suzuki, Kazuo T.; Somekawa, Layla; Suzuki, Noriyuki

    2006-01-01

    Nutritional selenium compounds are transformed to the common intermediate selenide and then utilized for selenoprotein synthesis or excreted in urine mostly as 1β-methylseleno-N-acetyl-DD-galactosamine (selenosugar). Since the biological significance of selenosugar formation is unknown, we investigated their role in the formation of selenoenzymes in selenium deficiency. Rats were depleted of endogenous natural abundance selenium with a single stable isotope ( 82 Se) and then made Se-deficient. 76 Se-Selenosugar was administered intravenously to the rats and their urine, serum, liver, kidneys and testes were subjected to speciation analysis with HPLC inductively coupled argon plasma mass spectrometry. Most 76 Se was recovered in its intact form (approximately 80% of dose) in urine within 1 h. Speciation analysis revealed that residual endogenous natural abundance selenium estimated by 77 Se and 78 Se was negligible and distinct distributions of the labeled 76 Se were detected in the body fluids and organs without interference from the endogenous natural abundance stable isotope. Namely, intact 76 Se-selenosugar was distributed to organs after the injection, and 76 Se was used for selenoprotein synthesis. Oxidation to methylseleninic acid and/or hydrolysis of the selenoacetal group to methylselenol were proposed to the transformation of selenosugar for the reuse. Effective use of an enriched stable isotope as an absolute label in hosts depleted of natural abundance isotopes was discussed for application in tracer experiments

  14. Insulators for Pb(1-x)Sn(x)Te

    Science.gov (United States)

    Tsuo, Y. H.; Sher, A.

    1981-01-01

    Thin films of LaF3 were e-gun and thermally deposited on several substrates. The e-gun deposited films are fluorine deficient, have high ionic conductivities that persist to 77 K, and high effective dielectric constants. The thermally deposited material tends to be closer to stoichiometric, and have higher effective breakdown field strengths. Thermally deposited LaF3 films with resistivities in excess of 10 to the 12th power ohms - cm were deposited on metal coated glass substrates. The LaF3 films were shown to adhere well to PbSnTe, surviving repeated cycles between room temperature and 77 K. The LaF3 films on GaAs were also studied.

  15. Isotopic dependence of photoneutron cross sections around Strontium (Z=38) and Cesium (Z=55) nuclei

    International Nuclear Information System (INIS)

    Nakamura, T.; Uno, Y.; Yamadera, A.; Kase, T.

    1992-01-01

    We measured the average cross sections of (γ,n) reactions for 84 Sr, 86 Sr, 88 Sr, 85 Rb, 87 Rb, 98 Ru and 104 Ru isotopes in giant resonance region (9 to 25 MeV) using Bremsstrahlung radiation of 60 MeV maximum energy. We investigated the isotopic dependence of the average (γ,n) cross sections in giant resonance region from our experimental data and those estimated from other experimental data for Ge, Se, Zr, Mo, Sn, Te, Ce, Nd and Sm isotopes. As a result, we found that the average cross section data become highest for nuclei of neutron magic number of N = 50 and 82 except for Mo nucleus

  16. Laser soldering of Sn-Ag-Cu and Sn-Zn-Bi lead-free solder pastes

    Science.gov (United States)

    Takahashi, Junichi; Nakahara, Sumio; Hisada, Shigeyoshi; Fujita, Takeyoshi

    2004-10-01

    It has reported that a waste of an electronics substrate including lead and its compound such as 63Sn-37Pb has polluted the environment with acid rain. For that environment problem the development of lead-free solder alloys has been promoted in order to find out the substitute for Sn-Pb solders in the United States, Europe, and Japan. In a present electronics industry, typical alloys have narrowed down to Sn-Ag-Cu and Sn-Zn lead-free solder. In this study, solderability of Pb-free solder that are Sn-Ag-Cu and Sn-Zn-Bi alloy was studied on soldering using YAG (yttrium aluminum garnet) laser and diode laser. Experiments were peformed in order to determine the range of soldering parameters for obtaining an appropriate wettability based on a visual inspection. Joining strength of surface mounting chip components soldered on PCB (printed circuit board) was tested on application thickness of solder paste (0.2, 0.3, and 0.4 mm). In addition, joining strength characteristics of eutectic Sn-Pb alloy and under different power density were examined. As a result, solderability of Sn-Ag-Cu (Pb-free) solder paste are equivalent to that of coventional Sn-Pb solder paste, and are superior to that of Sn-Zn-Bi solder paste in the laser soldering method.

  17. SN 2009E

    DEFF Research Database (Denmark)

    Pastorello...[], A.; Pumo, M.L.; Navasardyan, H.

    2012-01-01

    . In this paper we investigate the properties of SN 2009E, which exploded in a relatively nearby spiral galaxy (NGC 4141) and that is probably the faintest 1987A-like supernova discovered so far. We also attempt to characterize this subgroup of core-collapse supernovae with the help of the literature and present...... observations which started about 2 months after the supernova explosion, highlight significant differences between SN 2009E and the prototypical SN 1987A. Modelling the data of SN 2009E allows us to constrain the explosion parameters and the properties of the progenitor star, and compare the inferred estimates...... 2009E ejected about 0.04 M⊙ of 56Ni, which is the smallest 56Ni mass in our sample of 1987A-like events. Modelling the observations with a radiation hydrodynamics code, we infer for SN 2009E a kinetic plus thermal energy of about 0.6 foe, an initial radius of ~7 × 1012 cm and an ejected mass of ~19 M...

  18. Properties of Fe, Ni and Zn isotope chains near the drip-line

    International Nuclear Information System (INIS)

    Tarasov, V.N.; Tarasov, D.V.; Kuprikov, V.I.; Gridnev, K.A.; Gridnev, D.K.; Gridnev, K.A.; Gridnev, D.K.; Kartavenko, V.G.; Greiner, W.; Kartavenko, V.G.

    2007-01-01

    The location of proton and neutron drip-lines and the characteristics of the neutron-deficient and the neutron-rich isotopes Fe, Ni and Zn on the basis of Hartree-Fock method with Skyrme forces (Ska, SkM * , Sly4) taking into account deformation was investigated. The calculations predict a big jump of deformation parameter up to β ∼ 0.4 for Ni isotopes in the neighborhood of N ∼ 62. The manifestation of magic numbers for isotopes 48 Ni, 56 Ni, 78 Ni and also for the stable isotope in the respect to neutron emission 110 Ni which is situated beyond the neutron drip-line is discussed

  19. Dual isotopes imaging in whole-body autoradiography (WBARG). Distribution of 14C-benzo-a-pyrene and 113Sn-tributyltin in mummichog (Fundulus heteroclitus)

    International Nuclear Information System (INIS)

    Oliveira, H.H.P.; Ribeiro, C.A.O.; Rouleau, Claude; Desbiens, Isabelle; Pelletier, Emillien

    2016-01-01

    Tissue distributions of 14 C-BaP and 113 Sn-TBT, individually and together, were compared in mummichog by WBARG, after forced-feeding or intraperitoneal injection. Electron differential absorption (EDA) by metal foil was tested to visualize the distribution of 14 C and 113 Sn in tissue sections of animals exposed to both radiochemicals. Distribution of 14 C and 113 Sn in fish did not differ as a function of exposure route, but 14 C liver/blood and bile/ blood concentration ratios were lower in fish dosed with BaP + TBT. EDA allowed a clear differentiation of 14 C and 113 Sn signals and could be used to image other radionuclides pairs. (author)

  20. Preparation, deformation, and failure of functional Al-Sn and Al-Sn-Pb nanocrystalline alloys

    Science.gov (United States)

    Noskova, N. I.; Vil'Danova, N. F.; Filippov, Yu. I.; Churbaev, R. V.; Pereturina, I. A.; Korshunov, L. G.; Korznikov, A. V.

    2006-12-01

    Changes in the structure, hardness, mechanical properties, and friction coefficient of Al-30% Sn, Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb (wt %) alloys subjected to severe plastic deformation by equal-channel angular pressing (with a force of 40 tonne) and by shear at a pressure of 5 GPa have been studied. The transition into the nanocrystalline state was shown to occur at different degrees of plastic deformation. The hardness exhibits nonmonotonic variations, namely, first it increases and subsequently decreases. The friction coefficient of the Al-30% Sn, Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb alloys quenched from the melt was found to be 0.33; the friction coefficients of these alloys in the submicrocrystalline state (after equal-channel angular pressing) equal 0.24, 0.32, and 0.35, respectively. The effect of disintegration into nano-sized powders was found to occur in the Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb alloys after severe plastic deformation to ɛ = 6.4 and subsequent short-time holding.

  1. Electrochemical properties of Ti-Ni-Sn materials predicted by {sup 119}Sn Mössbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ladam, A., E-mail: alix.ladam@univ-montp2.fr; Aldon, L.; Lippens, P.-E.; Olivier-Fourcade, J.; Jumas, J.-C. [Université de Montpellier, Institut Charles Gerhardt, UMR 5253 CNRS (France); Cenac-Morthe, C. [CNES, Service DCT/TV/El (France)

    2016-12-15

    The electrochemical activity of TiNiSn, TiNi {sub 2}Sn and Ti {sub 6}Sn {sub 5} compounds considered as negative electrode materials for Li-ion batteries has been predicted from the isomer shift- Hume-Rothery electronic density correlation diagram. The ternary compounds were obtained from solid-state reactions and Ti {sub 6}Sn {sub 5} by ball milling. The {sup 119}Sn Mössbauer parameters were experimentally determined and used to evaluate the Hume-Rothery electronic density [e {sub av}]. The values of [e {sub av}] are in the region of Li-rich Li-Sn alloys for Ti {sub 6}Sn {sub 5} and outside this region for the ternary compounds, suggesting that the former compound is electrochemically active but not the two latter ones. Electrochemical tests were performed for these different materials confirming this prediction. The close values of [e {sub av}] for Ti {sub 6}Sn {sub 5} and Li-rich Li-Sn alloys indicate that the observed good capacity retention could be related to small changes in the global structures during cycling.

  2. Theoretical study of electronic structures and spectroscopic properties of Ga 3Sn, GaSn 3, and their ions

    Science.gov (United States)

    Zhu, Xiaolei

    2007-01-01

    Ground and excited states of mixed gallium stannide tetramers (Ga 3Sn, Ga 3Sn +, Ga 3Sn -, GaSn 3, GaSn 3+, and GaSn 3-) are investigated employing the complete active space self-consistent-field (CASSCF), density function theory (DFT), and the coupled-cluster single and double substitution (including triple excitations) (CCSD(T)) methods. The ground states of Ga 3Sn, Ga 3Sn +, and Ga 3Sn - are found to be the 2A 1, 3B 1, and 1A 1 states in C2v symmetry with a planar quadrilateral geometry, respectively. The ground states of GaSn 3 and GaSn 3- is predicted to be the 2A 1 and 1A 1 states in C2v point group with a planar quadrilateral structure, respectively, while the ground state of GaSn 3+ is the 1A 1 state with ideal triangular pyramid C3v geometry. Equilibrium geometries, vibrational frequencies, binding energies, electron affinities, ionization energies, and other properties of Ga 3Sn and GaSn 3 are computed and discussed. The anion photoelectron spectra of Ga 3Sn - and GaSn 3- are also predicted. It is interesting to find that the amount of charge transfer between Ga and Sn 2 atoms in the 1A 1 state of GaSn 3+ greatly increases upon electron ionization from the 2A 1 state of GaSn 3, which may be caused by large geometry change. On the other hand, the results of the low-lying states of Ga 3Sn and GaSn 3 are compared with those of Ga 3Si and GaSi 3.

  3. Electro-oxidation of Ethanol on Carbon Supported PtSn and PtSnNi Catalysts

    Directory of Open Access Journals (Sweden)

    Nur Hidayati

    2016-03-01

    Full Text Available Even though platinum is known as an active electro-catalyst for ethanol oxidation at low temperatures (< 100 oC, choosing the electrode material for ethanol electro-oxidation is a crucial issue. It is due to its property which easily poisoned by a strong adsorbed species such as CO. PtSn-based electro-catalysts have been identified as better catalysts for ethanol electro-oxidation. The third material is supposed to improved binary catalysts performance. This work presents a study of the ethanol electro-oxidation on carbon supported Pt-Sn and Pt-Sn-Ni catalysts. These catalysts were prepared by alcohol reduction. Nano-particles with diameters between 2.5-5.0 nm were obtained. The peak of (220 crystalline face centred cubic (fcc Pt phase for PtSn and PtSnNi alloys was repositioned due to the presence of Sn and/or Ni in the alloy. Furthermore, the modification of Pt with Sn and SnNi improved ethanol and CO electro-oxidation. Copyright © 2016 BCREC GROUP. All rights reserved Received: 10th November 2015; Revised: 1st February 2016; Accepted: 1st February 2016 How to Cite: Hidayati, N., Scott, K. (2016. Electro-oxidation of Ethanol on Carbon Supported PtSn and PtSnNi Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1: 10-20. (doi:10.9767/bcrec.11.1.394.10-20 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.394.10-20

  4. CONSTRUÇÕES BINOMINAIS DO TIPO SN1 DE SN2

    Directory of Open Access Journals (Sweden)

    Karen Sampaio Braga Alonso

    2017-04-01

    Full Text Available Este artigo tem por objetivo investigar a flutuação de sentido quantidade-qualidade licenciada pelo uso de construtos binominais do tipo SN1 de SN2, como xícara de chá, no Português do Brasil.A pesquisa é baseada na perspectiva teórica da Linguística Funcional Centrada no Uso (BYBEE, 2010; BARLOW E KEMMER, 2000; TOMASELLO, 2003, TRAUGOTT, 2008 e busca descrever as propriedades morfossintáticas, semântico-pragmáticas e cognitivas dos usos das construções que favorecem uma leitura ora qualitativa ora quantitativa, no que se refere à relação entre SN1 e SN2.

  5. Genome-wide transcriptional responses of Alteromonas naphthalenivorans SN2 to contaminated seawater and marine tidal flat sediment.

    Science.gov (United States)

    Jin, Hyun Mi; Jeong, Hye Im; Kim, Kyung Hyun; Hahn, Yoonsoo; Madsen, Eugene L; Jeon, Che Ok

    2016-02-18

    A genome-wide transcriptional analysis of Alteromonas naphthalenivorans SN2 was performed to investigate its ecophysiological behavior in contaminated tidal flats and seawater. The experimental design mimicked these habitats that either added naphthalene or pyruvate; tidal flat-naphthalene (TF-N), tidal flat-pyruvate (TF-P), seawater-naphthalene (SW-N), and seawater-pyruvate (SW-P). The transcriptional profiles clustered by habitat (TF-N/TF-P and SW-N/SW-P), rather than carbon source, suggesting that the former may exert a greater influence on genome-wide expression in strain SN2 than the latter. Metabolic mapping of cDNA reads from strain SN2 based on KEGG pathway showed that metabolic and regulatory genes associated with energy metabolism, translation, and cell motility were highly expressed in all four test conditions, probably highlighting the copiotrophic properties of strain SN2 as an opportunistic marine r-strategist. Differential gene expression analysis revealed that strain SN2 displayed specific cellular responses to environmental variables (tidal flat, seawater, naphthalene, and pyruvate) and exhibited certain ecological fitness traits -- its notable PAH degradation capability in seasonally cold tidal flat might be reflected in elevated expression of stress response and chaperone proteins, while fast growth in nitrogen-deficient and aerobic seawater probably correlated with high expression of glutamine synthetase, enzymes utilizing nitrite/nitrate, and those involved in the removal of reactive oxygen species.

  6. Ca isotopes in refractory inclusions

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.

    1984-01-01

    We report measurements of the absolute isotope abundance of Ca in Ca-Al-rich inclusions from the Allende and Leoville meteorites. Improved high precision measurements are reported also for 46 Ca. We find that nonlinear isotope effects in Ca are extremely rare in these inclusions. The absence of nonlinear effects in Ca, except for the effects in FUN inclusions, is in sharp contrast to the endemic effects in Ti. One fine-grained inclusion shows an excess of 46 Ca of (7 +- 1) per mille, which is consistent with addition of only 46 Ca or of an exotic (*) component with 46 Ca* approx. 48 Ca*. FUN inclusion EK-1-4-1 shows a small 46 Ca excess of (3.3 +- 1.0) per mille; this confirms that the exotic Ca components in EK-1-4-1 were even more deficient in 46 Ca relative to 48 Ca than is the case for normal Ca. The Ca in the Ca-Al-rich inclusions shows mass dependent isotope fractionation effects which have a range from -3.8 to +6.7 per mille per mass unit difference. This range is a factor of 20 wider than the range previously established for bulk meteorites and for terrestrial and lunar samples. Ca and Mg isotope fractionation effects in the Ca-Al-rich inclusions are common and attributed to kinetic isotope effects. (author)

  7. SN 2013fs and SN 2013fr: exploring the circumstellar-material diversity in Type II supernovae

    Science.gov (United States)

    Bullivant, Christopher; Smith, Nathan; Williams, G. Grant; Mauerhan, Jon C.; Andrews, Jennifer E.; Fong, Wen-Fai; Bilinski, Christopher; Kilpatrick, Charles D.; Milne, Peter A.; Fox, Ori D.; Cenko, S. Bradley; Filippenko, Alexei V.; Zheng, WeiKang; Kelly, Patrick L.; Clubb, Kelsey I.

    2018-05-01

    We present photometry and spectroscopy of SN 2013fs and SN 2013fr in the first ˜100 d post-explosion. Both objects showed transient, relatively narrow H α emission lines characteristic of SNe IIn, but later resembled normal SNe II-P or SNe II-L, indicative of fleeting interaction with circumstellar material (CSM). SN 2013fs was discovered within 8 h of explosion; one of the earliest SNe discovered thus far. Its light curve exhibits a plateau, with spectra revealing strong CSM interaction at early times. It is a less luminous version of the transitional SN IIn PTF11iqb, further demonstrating a continuum of CSM interaction intensity between SNe II-P and SNe IIn. It requires dense CSM within 6.5 × 1014 cm of the progenitor, from a phase of advanced pre-SN mass loss beginning shortly before explosion. Spectropolarimetry of SN 2013fs shows little continuum polarization (˜0.5 per cent, consistent with zero), but noticeable line polarization during the plateau phase. SN 2013fr morphed from an SN IIn at early times to an SN II-L. After the first epoch, its narrow lines probably arose from host-galaxy emission, but the bright, narrow H α emission at early times may be intrinsic to the SN. As for SN 2013fs, this would point to a short-lived phase of strong CSM interaction if proven to be intrinsic, suggesting a continuum between SNe IIn and SNe II-L. It is a low-velocity SN II-L like SN 2009kr, but more luminous. SN 2013fr also developed an infrared excess at later times, due to warm CSM dust that requires a more sustained phase of strong pre-SN mass loss.

  8. Co-ordinated research project on isotopic and complementary tools for the study of micronutrient status and interactions in developing country populations exposed to multiple nutritional deficiencies. Report on the first research co-ordination meeting

    International Nuclear Information System (INIS)

    2002-01-01

    From a global perspective and in spite of decades of nutrition programmes, micronutrients deficiency is at alarming proportions in many developing societies today. It affects millions of people worldwide, and includes consequences that potentially compromise morbidity, mortality, cognitive development, and growth, reproductive and work capacity. Recent estimates by the WHO are that deficiencies of iron (Fe), iodine (I), and vitamin A continue to influence the health of 2000 million, 740 million, and 250 million persons respectively. In addition to these three micronutrients, the possible negative consequences of deficiencies of zinc (Zn), copper (Cu) and selenium (Se) are now also being increasingly recognized as important health concerns. As a result of the increasing recognition of the co-existence of multiple micronutrient deficiencies in developing countries, United Nations Agencies have urged that supplementation, fortification and dietary modification/diversification programmes are designed to combat multiple micronutrient deficiencies simultaneously. Fortificant levels for fortification, like supplementation, must be carefully selected to minimize risk of antagonistic nutrient interactions and to take into account the toxic threshold level for normal individuals. Possible antagonistic interactions that may interfere with the utilisation of trace elements in the supplements or fortificants per se, and/or with the utilization of elements intrinsic to the food or the meal include those between Cu-Zn, Cu-Fe, Fe-Zn, Mn-Fe, Ca-Zn. Stable isotope techniques play an important role in quantifying the optimal levels and the bioavailability of micronutrient supplements and fortificants for a range of indigenous meals consumed in developing countries, especially those containing potent absorption inhibitors. This Capacity building CRP or Thermatic CRP (T-CRP) addresses the need to develop effective strategies to combat micro-nutrient malnutrition in developing countries

  9. Co-ordinated research project on isotopic and complementary tools for the study of micronutrient status and interactions in developing country populations exposed to multiple nutritional deficiencies. Report on the first research co-ordination meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    From a global perspective and in spite of decades of nutrition programmes, micronutrients deficiency is at alarming proportions in many developing societies today. It affects millions of people worldwide, and includes consequences that potentially compromise morbidity, mortality, cognitive development, and growth, reproductive and work capacity. Recent estimates by the WHO are that deficiencies of iron (Fe), iodine (I), and vitamin A continue to influence the health of 2000 million, 740 million, and 250 million persons respectively. In addition to these three micronutrients, the possible negative consequences of deficiencies of zinc (Zn), copper (Cu) and selenium (Se) are now also being increasingly recognized as important health concerns. As a result of the increasing recognition of the co-existence of multiple micronutrient deficiencies in developing countries, United Nations Agencies have urged that supplementation, fortification and dietary modification/diversification programmes are designed to combat multiple micronutrient deficiencies simultaneously. Fortificant levels for fortification, like supplementation, must be carefully selected to minimize risk of antagonistic nutrient interactions and to take into account the toxic threshold level for normal individuals. Possible antagonistic interactions that may interfere with the utilisation of trace elements in the supplements or fortificants per se, and/or with the utilization of elements intrinsic to the food or the meal include those between Cu-Zn, Cu-Fe, Fe-Zn, Mn-Fe, Ca-Zn. Stable isotope techniques play an important role in quantifying the optimal levels and the bioavailability of micronutrient supplements and fortificants for a range of indigenous meals consumed in developing countries, especially those containing potent absorption inhibitors. This Capacity building CRP or Thermatic CRP (T-CRP) addresses the need to develop effective strategies to combat micro-nutrient malnutrition in developing countries

  10. SnO and SnO·CoO nanocomposite as high capacity anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Das, B., E-mail: bijoy822000@gmail.com; Reddy, M.V.; Chowdari, B.V.R, E-mail: phychowd@nus.edu.sg

    2016-02-15

    Highlights: • The preparation methods are simple, low cost and can be scaled up for large production. • SnO is cheap, non-toxic and eco-friendly. • SnO shows high reversible capacity (Theoretical reversible capacity: 875 mA h g{sup −1}). • We showed high reversible capacity and columbic efficiency for SnO and SnO based composites. • We addressed the capacity degradation by introducing secondary phase (CoO and CNT etc.) - Abstract: We prepared SnO nanoparticles (SnO–S) and SnO·CoO nanocomposites (SnO·CoO–B) as anodes for lithium ion batteries (LIBs) by chemical and ball-milling approaches, respectively. They are characterized by X-ray diffraction and TEM techniques. The Li- storage performance are evaluated by galvanostatic cycling and cyclic voltammetry. The SnO–S and SnO·CoO–B showed improved cycling performance due to their finite particle size (i.e. nano-size) and presence of secondary phase (CoO). Better cycling stability is noticed for SnO·CoO–B with the expense of their reversible capacity. Also, addition of carbon nanotubes (CNT) to SnO–S further improved the cycling performance of SnO–S. When cycled at 60 mA g{sup −1}, the first-cycle reversible capacities of 635, 590 and 460 (±10) mA h g{sup −1} are noticed for SnO–S, SnO@CNT and SnO·CoO–B, respectively. The capacity fading observed are 3.7 and 1.8 mA h g{sup −1} per cycle for SnO–S and SnO@CNT, respectively; whereas 1–1.2 mA h g{sup −1} per cycle for SnO·CoO–B. All the samples show high coulombic efficiency, 96–98% in the range of 5–50 cycles.

  11. Effect of pH on the electrical properties and conducting mechanism of SnO_2 nanoparticles

    International Nuclear Information System (INIS)

    Periathai, R.Sudha; Abarna, S.; Hirankumar, G.; Jeyakumaran, N.; Prithivikumaran, N.

    2017-01-01

    Semiconductor nanoparticles have attracted more interests because of their size-dependent optical and electrical properties.SnO_2 is an oxygen-deficient n-type semiconductor with a wide band gap of 3.6 eV (300 K). It has many remarkable applications as sensors, catalysts, transparent conducting electrodes, anode material for rechargeable Li- ion batteries and optoelectronic devices. In the present work, the role of pH in determining the electrical and dielectric properties of SnO_2 nanoparticles has been studied as a function of temperature ranging from Room temperature (RT) to 114 °C in the frequency range of 7 MHz to 50 mHz using impedance spectroscopic technique. The non linear behavior observed in the thermal dependence of the conductance of SnO_2 nanoparticles is explained by means of the surface property of SnO_2 nanoparticles where proton hopping mechanism is dealt with. Jonscher's power law has been fitted for the conductance spectra and the frequency exponent (“s” value) gives an insight about the ac conducting mechanism. The temperature dependence of electrical relaxation phenomenon in the material has been observed. The complex electric modulus analysis indicates the possibility of hopping conduction mechanism in the system with non-exponential type of conductivity relaxation.

  12. Laser spectroscopy of laser-desorbed gold isotopes

    International Nuclear Information System (INIS)

    Savard, G.; Crawford, J.E.; Lee, J.K.P.; Thekkadath, G.

    1990-01-01

    Changes in mean-square charge radius δ 2 >, and magnetic dipole moments μ I have been measured for a series of neutron-deficient gold isotopes between A=186 and 196, and for neutron-rich 198,199 Au, using the PILIS system on-line with the ISOCELE mass separator. These measurements confirm the existence of the shape transition between A=186 and 187. The measured μ I values have been compared with calculations using Nilsson, and symmetric-rotor-plus-quasiparticle models. The results are consistent with the interpretation that 186 Au is prolate, and that the heavier isotopes have oblate, or possibly triaxial deformation. (orig.)

  13. Isotope techniques in human studies of zinc nutrition. Report of an IAEA consultants' meeting

    International Nuclear Information System (INIS)

    1997-01-01

    A Consultants' Meeting was convened by the IAEA in November 1996 to review current knowledge of the role of zinc in human nutrition - with particular reference to (1) relevant public health issues in developing countries, and (2) the role that isotope techniques can play in increasing our understanding of some of these matters. More specifically, the Consultants Group was invited to advise the Agency on its future programmes in this area. It was concluded that there is now abundant scientific evidence that zinc deficiency of nutritional origin is a widespread phenomenon with important health consequences, particularly in developing countries. Even mild zinc deficiency is now thought to contribute to pregnancy complications, low birth weight, impaired immune competence, maternal and infant mortality and morbidity, and growth failure in infancy and childhood. Hence zinc deficiency may have far-reaching consequences for maternal, infant and child health in many developing countries. Isotope techniques - mainly using stable isotopes of zinc, but in some cases using radioisotopes - provide many possibilities 'for improving our understanding of the basic biochemical and metabolic functions of zinc, and for increasing our knowledge of the roles of this essential micronutrient in human nutrition. Through the use of isotope techniques, we may also expect to be better able to assess, and to increase, the efficacy of dietary and other intervention programmes designed to improve the nutritional status of developing country populations whose intakes are below the levels needed to achieve optimal health. This report briefly reviews some of these isotope techniques and makes recommendations on their use in IAEA research and technical co-operation programmes

  14. Isotope techniques in human studies of zinc nutrition. Report of an IAEA consultants` meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    A Consultants` Meeting was convened by the IAEA in November 1996 to review current knowledge of the role of zinc in human nutrition - with particular reference to (1) relevant public health issues in developing countries, and (2) the role that isotope techniques can play in increasing our understanding of some of these matters. More specifically, the Consultants Group was invited to advise the Agency on its future programmes in this area. It was concluded that there is now abundant scientific evidence that zinc deficiency of nutritional origin is a widespread phenomenon with important health consequences, particularly in developing countries. Even mild zinc deficiency is now thought to contribute to pregnancy complications, low birth weight, impaired immune competence, maternal and infant mortality and morbidity, and growth failure in infancy and childhood. Hence zinc deficiency may have far-reaching consequences for maternal, infant and child health in many developing countries. Isotope techniques - mainly using stable isotopes of zinc, but in some cases using radioisotopes - provide many possibilities `for improving our understanding of the basic biochemical and metabolic functions of zinc, and for increasing our knowledge of the roles of this essential micronutrient in human nutrition. Through the use of isotope techniques, we may also expect to be better able to assess, and to increase, the efficacy of dietary and other intervention programmes designed to improve the nutritional status of developing country populations whose intakes are below the levels needed to achieve optimal health. This report briefly reviews some of these isotope techniques and makes recommendations on their use in IAEA research and technical co-operation programmes

  15. Application of zinc isotope tracer technology in tracing soil heavy metal pollution

    Science.gov (United States)

    Norbu, Namkha; Wang, Shuguang; Xu, Yan; Yang, Jianqiang; Liu, Qiang

    2017-08-01

    Recent years the soil heavy metal pollution has become increasingly serious, especially the zinc pollution. Due to the complexity of this problem, in order to prevent and treat the soil pollution, it's crucial to accurately and quickly find out the pollution sources and control them. With the development of stable isotope tracer technology, it's able to determine the composition of zinc isotope. Based on the theory of zinc isotope tracer technique, and by means of doing some latest domestic and overseas literature research about the zinc isotope multi-receiving cups of inductively coupled plasma mass spectrometer (MC-ICP-MS) testing technology, this paper summarized the latest research results about the pollution tracer of zinc isotope, and according to the deficiencies and existing problems of previous research, made outlooks of zinc isotope fractionation mechanism, repository establishment and tracer multiple solutions.

  16. Accurate masses of unstable rare earth isotopes by ISOLTRAP

    International Nuclear Information System (INIS)

    Beck, D.; Ames, F.; Audi, G.

    2000-05-01

    Direct mass measurements of neutron-deficient rare earth isotopes in the vicinity of 146 Gd were performed with the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. This paper reports on the measurement of more than 40 isotopes of the elements Pr, Nd, Pm, Sm, Eu, Dy and Ho, that have been measured with a typical accuracy of δm ∼ 14 keV. An atomic mass evaluation has been performed taking into account other experimental mass values via a least-squares adjustment. The results of the adjustment are discussed. (orig.)

  17. Sn powder as reducing agents and SnO2 precursors for the synthesis of SnO2-reduced graphene oxide hybrid nanoparticles.

    Science.gov (United States)

    Chen, Mingxi; Zhang, Congcong; Li, Lingzhi; Liu, Yu; Li, Xichuan; Xu, Xiaoyang; Xia, Fengling; Wang, Wei; Gao, Jianping

    2013-12-26

    A facile approach to prepare SnO2/rGO (reduced graphene oxide) hybrid nanoparticles by a direct redox reaction between graphene oxide (GO) and tin powder was developed. Since no acid was used, it is an environmentally friendly green method. The SnO2/rGO hybrid nanoparticles were characterized by ultraviolet-visible spectroscopy, Raman spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The microstructure of the SnO2/rGO was observed with scanning electron microscopy and transmission electron microscopy. The tin powder efficiently reduced GO to rGO, and the Sn was transformed to SnO2 nanoparticles (∼45 nm) that were evenly distributed on the rGO sheets. The SnO2/rGO hybrid nanoparticles were then coated on an interdigital electrode to fabricate a humidity sensor, which have an especially good linear impedance response from 11% to 85% relative humidity.

  18. Behavior of Sn atoms in GeSn thin films during thermal annealing: Ex-situ and in-situ observations

    Science.gov (United States)

    Takase, Ryohei; Ishimaru, Manabu; Uchida, Noriyuki; Maeda, Tatsuro; Sato, Kazuhisa; Lieten, Ruben R.; Locquet, Jean-Pierre

    2016-12-01

    Thermally induced crystallization processes for amorphous GeSn thin films with Sn concentrations beyond the solubility limit of the bulk crystal Ge-Sn binary system have been examined by X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, and (scanning) transmission electron microscopy. We paid special attention to the behavior of Sn before and after recrystallization. In the as-deposited specimens, Sn atoms were homogeneously distributed in an amorphous matrix. Prior to crystallization, an amorphous-to-amorphous phase transformation associated with the rearrangement of Sn atoms was observed during heat treatment; this transformation is reversible with respect to temperature. Remarkable recrystallization occurred at temperatures above 400 °C, and Sn atoms were ejected from the crystallized GeSn matrix. The segregation of Sn became more pronounced with increasing annealing temperature, and the ejected Sn existed as a liquid phase. It was found that the molten Sn remains as a supercooled liquid below the eutectic temperature of the Ge-Sn binary system during the cooling process, and finally, β-Sn precipitates were formed at ambient temperature.

  19. A facile inexpensive route for SnS thin film solar cells with SnS{sub 2} buffer

    Energy Technology Data Exchange (ETDEWEB)

    Gedi, Sreedevi [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Minna Reddy, Vasudeva Reddy, E-mail: drmvasudr9@gmail.com [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Pejjai, Babu [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Jeon, Chan-Wook [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Park, Chinho, E-mail: chpark@ynu.ac.kr [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Ramakrishna Reddy, K.T., E-mail: ktrkreddy@gmail.com [Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India)

    2016-05-30

    Graphical abstract: PYS spectra of SnS/SnS{sub 2} interface and the related band diagram. - Highlights: • A low cost SnS solar cell is developed using chemical bath deposition. • We found E{sub I} & χ of SnS (5.3 eV & 4.0 eV) and SnS{sub 2} (6.9 eV & 4.1 eV) films from PYS. • Band offsets of 0.1 eV (E{sub c}) and 1.6 eV (E{sub v}) are estimated for SnS/SnS{sub 2} junction. • SnS based solar cell showed a conversion efficiency of 0.51%. - Abstract: Environment-friendly SnS based thin film solar cells with SnS{sub 2} as buffer layer were successfully fabricated from a facile inexpensive route, chemical bath deposition (CBD). Layer studies revealed that as-grown SnS and SnS{sub 2} films were polycrystalline; (1 1 1)/(0 0 1) peaks as the preferred orientation; 1.3 eV/2.8 eV as optical band gaps; and showed homogeneous microstructure with densely packed grains respectively. Ionization energy and electron affinity values were found by applying photoemission yield spectroscopy (PYS) to the CBD deposited SnS and SnS{sub 2} films for the first time. These values obtained as 5.3 eV and 4.0 eV for SnS films; 6.9 eV and 4.1 eV for SnS{sub 2} films. The band alignment of SnS/SnS{sub 2} junction showed TYPE-II heterostructure. The estimated conduction and valance band offsets were 0.1 eV and 1.6 eV respectively. The current density–voltage (J–V) measurements of the cell showed open circuit voltage (V{sub oc}) of 0.12 V, short circuit current density (J{sub sc}) of 10.87 mA cm{sup −2}, fill factor (FF) of 39% and conversion efficiency of 0.51%.

  20. Synthesis and properties of neutron deficient isotopes of elements around Z=100

    International Nuclear Information System (INIS)

    Antalic, S.

    2005-01-01

    In the presented Thesis work the results of spectroscopic studies of 246 Md, 247 Md, 254 Lr and 255 Lr decay chains are given. These isotopes were produced using heavy ion induced fusion reactions of 40 Ar + 209 Bi and 48 Ca + 209 Bi as a part of the long term project aimed to study spectroscopy properties of superheavy elements. The experiments were performed at velocity filter SHIP, placed at the central beam line of the UNILAC accelerator at GSI Darmstadt in Germany. The work also gives a basic overview of research in the region of superheavy elements, description of the used experimental setup and shows the usual analysis methods used in spectroscopic studies in the region of elements around Z ∼ 100. The results were obtained using α, α - γ spectroscopy methods and recoil - α, α - α correlations search. Although these isotopes have been known for a longer time, no detailed spectroscopy investigation were performed so far and only rough information was known. Beside the improved precision of known data, this work gives a new information about the decay properties of these isotopes. This give us the possibility to build a decay schemes for mentioned decay chains. (author)

  1. Accurate mass measurements on neutron-deficient krypton isotopes

    CERN Document Server

    Rodríguez, D.; Äystö, J.; Beck, D.; Blaum, K.; Bollen, G.; Herfurth, F.; Jokinen, A.; Kellerbauer, A.; Kluge, H.-J.; Kolhinen, V.S.; Oinonen, M.; Sauvan, E.; Schwarz, S.

    2006-01-01

    The masses of $^{72–78,80,82,86}$Kr were measured directly with the ISOLTRAP Penning trap mass spectrometer at ISOLDE/CERN. For all these nuclides, the measurements yielded mass uncertainties below 10 keV. The ISOLTRAP mass values for $^{72–75}$Kr being more precise than the previous results obtained by means of other techniques, and thus completely determine the new values in the Atomic-Mass Evaluation. Besides the interest of these masses for nuclear astrophysics, nuclear structure studies, and Standard Model tests, these results constitute a valuable and accurate input to improve mass models. In this paper, we present the mass measurements and discuss the mass evaluation for these Kr isotopes.

  2. The 7SK snRNP associates with the little elongation complex to promote snRNA gene expression.

    Science.gov (United States)

    Egloff, Sylvain; Vitali, Patrice; Tellier, Michael; Raffel, Raoul; Murphy, Shona; Kiss, Tamás

    2017-04-03

    The 7SK small nuclear RNP (snRNP), composed of the 7SK small nuclear RNA (snRNA), MePCE, and Larp7, regulates the mRNA elongation capacity of RNA polymerase II (RNAPII) through controlling the nuclear activity of positive transcription elongation factor b (P-TEFb). Here, we demonstrate that the human 7SK snRNP also functions as a canonical transcription factor that, in collaboration with the little elongation complex (LEC) comprising ELL, Ice1, Ice2, and ZC3H8, promotes transcription of RNAPII-specific spliceosomal snRNA and small nucleolar RNA (snoRNA) genes. The 7SK snRNA specifically associates with a fraction of RNAPII hyperphosphorylated at Ser5 and Ser7, which is a hallmark of RNAPII engaged in snRNA synthesis. Chromatin immunoprecipitation (ChIP) and chromatin isolation by RNA purification (ChIRP) experiments revealed enrichments for all components of the 7SK snRNP on RNAPII-specific sn/snoRNA genes. Depletion of 7SK snRNA or Larp7 disrupts LEC integrity, inhibits RNAPII recruitment to RNAPII-specific sn/snoRNA genes, and reduces nascent snRNA and snoRNA synthesis. Thus, through controlling both mRNA elongation and sn/snoRNA synthesis, the 7SK snRNP is a key regulator of nuclear RNA production by RNAPII. © 2017 The Authors.

  3. Process for the exchange of hydrogen isotopes between streams of liquid water and gaseous halohydrocarbon and an apparatus therefor

    International Nuclear Information System (INIS)

    Symons, E.A.; Rolston, J.H.; Clermont, M.J.; Paterson, L.M.

    1983-01-01

    This invention provides a process for the exchange of hydrogen isotopes between streams of liquid water and gaseous halohydrocarbons comprising: (a) bringing into contact a water stream, a halohydrocarbon stream, and a catalytic porous anion exchange resin so that the isotope-deficient halohydrocarbon stream is enriched; (b) decomposing the halohydrocarbon stream photolytically into two gaseous streams, one enriched and the other deficient; (c) removing as a product the first, enriched stream; and (d) recycling the second stream for enrichment. An apparatus is also provided

  4. Effect of Sn addition on the microstructure and superelasticity in Ti-Nb-Mo-Sn alloys.

    Science.gov (United States)

    Zhang, D C; Yang, S; Wei, M; Mao, Y F; Tan, C G; Lin, J G

    2012-09-01

    Ti-7.5Nb-4Mo-xSn (x=0-4at%) alloys were developed as the biomedical materials. The effect of the Sn content on the microstructure and superelasticity of the alloys was investigated. It is found that Sn is a strong stabilizer of the β phase, which is effective in suppressing the formation of α″ and ω phases in the alloys. Moreover, the Sn addition has a significant impact on the mechanical properties of the alloys. With the increase of Sn addition, the yield stress of the alloys increase, but their elastic modulus, the fracture strength and the ductility decrease, and the deformation mode of the alloys changes from (322) twining to α″ transformation and then to slip. The Ti-7.5Nb-4Mo-1Sn and Ti-7.5Nb-4Mo-3Sn alloys exhibit a good superelasticity with a high σ(SIM) due to the relatively high athermal ω phases containing or the solution hardening at room temperature. Under the maximum strain of 5%, Ti-7.5Nb-4Mo-3Sn (at%) alloy exhibits higher super elastic stability than that of Ti-7.5Nb-4Mo-1Sn alloy. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Fabrication of high crystalline SnS and SnS2 thin films, and their switching device characteristics

    Science.gov (United States)

    Choi, Hyeongsu; Lee, Jeongsu; Shin, Seokyoon; Lee, Juhyun; Lee, Seungjin; Park, Hyunwoo; Kwon, Sejin; Lee, Namgue; Bang, Minwook; Lee, Seung-Beck; Jeon, Hyeongtag

    2018-05-01

    Representative tin sulfide compounds, tin monosulfide (SnS) and tin disulfide (SnS2) are strong candidates for future nanoelectronic devices, based on non-toxicity, low cost, unique structures and optoelectronic properties. However, it is insufficient for synthesizing of tin sulfide thin films using vapor phase deposition method which is capable of fabricating reproducible device and securing high quality films, and their device characteristics. In this study, we obtained highly crystalline SnS thin films by atomic layer deposition and obtained highly crystalline SnS2 thin films by phase transition of the SnS thin films. The SnS thin film was transformed into SnS2 thin film by annealing at 450 °C for 1 h in H2S atmosphere. This phase transition was confirmed by x-ray diffractometer and x-ray photoelectron spectroscopy, and we studied the cause of the phase transition. We then compared the film characteristics of these two tin sulfide thin films and their switching device characteristics. SnS and SnS2 thin films had optical bandgaps of 1.35 and 2.70 eV, and absorption coefficients of about 105 and 104 cm‑1 in the visible region, respectively. In addition, SnS and SnS2 thin films exhibited p-type and n-type semiconductor characteristics. In the images of high resolution-transmission electron microscopy, SnS and SnS2 directly showed a highly crystalline orthorhombic and hexagonal layered structure. The field effect transistors of SnS and SnS2 thin films exhibited on–off drain current ratios of 8.8 and 2.1 × 103 and mobilities of 0.21 and 0.014 cm2 V‑1 s‑1, respectively. This difference in switching device characteristics mainly depends on the carrier concentration because it contributes to off-state conductance and mobility. The major carrier concentrations of the SnS and SnS2 thin films were 6.0 × 1016 and 8.7 × 1013 cm‑3, respectively, in this experiment.

  6. Laser Isotope Enrichment for Medical and Industrial Applications

    Energy Technology Data Exchange (ETDEWEB)

    Leonard Bond

    2006-07-01

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: 1) Pure isotopic targets for irradiation to produce medical radioisotopes. 2) Pure isotopes for semiconductors. 3) Low neutron capture isotopes for various uses in nuclear reactors. 4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ”calutrons” (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation

  7. Laser Isotope Enrichment for Medical and Industrial Applications

    International Nuclear Information System (INIS)

    Leonard Bond

    2006-01-01

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: (1) Pure isotopic targets for irradiation to produce medical radioisotopes. (2) Pure isotopes for semiconductors. (3) Low neutron capture isotopes for various uses in nuclear reactors. (4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ''calutrons'' (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation

  8. Rational design of Sn/SnO{sub 2}/porous carbon nanocomposites as anode materials for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaojia [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Xifei, E-mail: xfli2011@hotmail.com [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Center for Advanced Energy Materials and Devices, Xi’an University of Technology, Xi’an 710048 (China); Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Collaborative Innovation Center of Chemical Science and Engineering, College of Chemistry, Nankai University, Tianjin 300071 (China); Fan, Linlin; Yu, Zhuxin; Yan, Bo; Xiong, Dongbin; Song, Xiaosheng; Li, Shiyu [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Adair, Keegan R. [Nanomaterials and Energy Lab., Department of Mechanical and Materials Engineering, Western University, London, Ontario N6A 5B9 (Canada); Li, Dejun, E-mail: dejunli@mail.tjnu.edu.cn [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Sun, Xueliang, E-mail: xsun9@uwo.ca [Nanomaterials and Energy Lab., Department of Mechanical and Materials Engineering, Western University, London, Ontario N6A 5B9 (Canada); Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China)

    2017-08-01

    Highlights: • Sn/SnO{sub 2}/porous carbon nanocomposites are rationally designed via a facile strategy. • The porous carbon mitigates the volume change and poor conductivity of Sn/SnO{sub 2}. • The nanocomposites exhibit the enhanced sodium storage performance. - Abstract: Sodium-ion batteries (SIBs) have successfully attracted considerable attention for application in energy storage, and have been proposed as an alternative to lithium ion batteries (LIBs) due to the abundance of sodium resources and low price. Sn has been deemed as a promising anode material in SIBs which holds high theoretical specific capacity of 845 mAh g{sup −1}. In this work we design nanocomposite materials consisting of porous carbon (PC) with SnO{sub 2} and Sn (Sn/SnO{sub 2}/PC) via a facile reflux method. Served as an anode material for SIBs, the Sn/SnO{sub 2}/PC nanocomposite delivers the primary discharge and charge capacities of 1148.1 and 303.0 mAh g{sup −1}, respectively. Meanwhile, it can preserve the discharge capacity approximately of 265.4 mAh g{sup −1} after 50 cycles, which is much higher than those of SnO{sub 2}/PC (138.5 mAh g{sup −1}) and PC (92.2 mAh g{sup −1}). Furthermore, the Sn/SnO{sub 2}/PC nanocomposite possesses better cycling stability with 77.8% capacity retention compared to that of SnO{sub 2}/PC (61.88%) over 50 cycles. Obviously, the Sn/SnO{sub 2}/PC composite with excellent electrochemical performance shows the great possibility of application in SIBs.

  9. In-source laser spectroscopy of mercury isotopes

    CERN Multimedia

    This proposal follows on from the Letter of Intent, I-153. The neutron-deficient mercury isotopes are one of the prime examples of shape coexistence anywhere in the nuclear chart. Wide-ranging and complementary experimental and theoretical approaches have been used to investigate their structure over the last few years, however mean-square charge radii are unknown for isotopes with $\\textit{A}$ < 181. It is proposed to measure the isotope shift (IS) and hyperfine structure (HFS) of the 253-nm transition in $^{177-182}$Hg in an attempt to study the propagation of the famous odd-even staggering behaviour. At the other end of the chain, no information exists on the optical spectroscopy of Hg isotopes beyond the $\\textit{N}$ = 126 shell closure. There is a well-known "kink" in mean-square charge radii beyond this point in the even $\\textit{Z}$ $\\geq$ 82 elements. It is proposed to measure the IS of $^{207,208}$Hg in order to provide the first information on this effect below $\\textit{Z}$ = 82.

  10. Hierarchical Graphene-Encapsulated Hollow SnO2@SnS2 Nanostructures with Enhanced Lithium Storage Capability.

    Science.gov (United States)

    Xu, Wangwang; Xie, Zhiqiang; Cui, Xiaodan; Zhao, Kangning; Zhang, Lei; Dietrich, Grant; Dooley, Kerry M; Wang, Ying

    2015-10-14

    Complex hierarchical structures have received tremendous attention due to their superior properties over their constitute components. In this study, hierarchical graphene-encapsulated hollow SnO2@SnS2 nanostructures are successfully prepared by in situ sulfuration on the backbones of hollow SnO2 spheres via a simple hydrothermal method followed by a solvothermal surface modification. The as-prepared hierarchical SnO2@SnS2@rGO nanocomposite can be used as anode material in lithium ion batteries, exhibiting excellent cyclability with a capacity of 583 mAh/g after 100 electrochemical cycles at a specific current of 200 mA/g. This material shows a very low capacity fading of only 0.273% per cycle from the second to the 100th cycle, lower than the capacity degradation of bare SnO2 hollow spheres (0.830%) and single SnS2 nanosheets (0.393%). Even after being cycled at a range of specific currents varied from 100 mA/g to 2000 mA/g, hierarchical SnO2@SnS2@rGO nanocomposites maintain a reversible capacity of 664 mAh/g, which is much higher than single SnS2 nanosheets (374 mAh/g) and bare SnO2 hollow spheres (177 mAh/g). Such significantly improved electrochemical performance can be attributed to the unique hierarchical hollow structure, which not only effectively alleviates the stress resulting from the lithiation/delithiation process and maintaining structural stability during cycling but also reduces aggregation and facilitates ion transport. This work thus demonstrates the great potential of hierarchical SnO2@SnS2@rGO nanocomposites for applications as a high-performance anode material in next-generation lithium ion battery technology.

  11. Site occupancy, composition and magnetic structure dependencies of martensitic transformation in Mn2Ni1 + x Sn1-x.

    Science.gov (United States)

    Kundu, Ashis; Ghosh, Subhradip

    2017-11-29

    A delicate balance between various factors such as site occupancy, composition and magnetic ordering seems to affect the stability of the martensitic phase in [Formula: see text] [Formula: see text] [Formula: see text]. Using first-principles DFT calculations, we explore the impacts of each one of these factors on the martensitic stability of this system. Our results on total energies, magnetic moments and electronic structures upon changes in the composition, the magnetic configurations and the site occupancies show that the occupancies at the 4d sites in the inverse Heusler crystal structure play the most crucial role. The presence of Mn at the 4d sites originally occupied by Sn and its interaction with the Mn atoms at other sites decide the stability of the martensitic phases. This explains the discrepancy between the experiments and earlier DFT calculations regarding phase stability in [Formula: see text]NiSn. Our results qualitatively explain the trends observed experimentally with regard to martensitic phase stability and the magnetisations in Ni-excess, Sn-deficient [Formula: see text]NiSn system.

  12. In situ 119Sn Moessbauer spectroscopy used to study lithium insertion in c-Mg2Sn

    International Nuclear Information System (INIS)

    Aldon, L.; Ionica, C. M.; Lippens, P. E.; Larcher, D.; Tarascon, J.-M.; Olivier-Fourcade, J.; Jumas, J.-C.

    2006-01-01

    The electrochemical reactions of Li with c-Mg 2 Sn have been investigated by in situ Moessbauer spectroscopy of 119 Sn and X-ray diffraction. The lithiation transforms initially c-Mg 2 Sn part into Li x Mg 2 Sn alloy (x 2 MgSn ternary alloy. In situ Moessbauer spectroscopy provides valuable information on local environment of tin and swelling behavior and cracking of the particles during discharge and charge processes.

  13. NanoSIMS isotope studies of rare types of presolar silicon carbide grains from the Murchison meteorite: Implications for supernova models and the role of 14C

    Science.gov (United States)

    Hoppe, Peter; Pignatari, Marco; Kodolányi, János; Gröner, Elmar; Amari, Sachiko

    2018-01-01

    We have conducted a NanoSIMS ion imaging survey of about 1800 presolar silicon carbide (SiC) grains from the Murchison meteorite. A total of 21 supernova (SN) X grains, two SN C grains, and two putative nova grains were identified. Six particularly interesting grains, two X and C grains each and the two putative nova grains were subsequently studied in greater detail, namely, for C-, N-, Mg-Al-, Si-, S-, and Ca-Ti-isotopic compositions and for the initial presence of radioactive 26Al (half life 716,000 yr), 32Si (half life 153 yr), and 44Ti (half life 60 yr). Their isotope data along with those of three X grains from the literature were compared with model predictions for 15 M⊙ and 25 M⊙ Type II supernovae (SNe). The best fits were found for 25 M⊙ SN models that consider for the He shell the temperature and density of a 15 M⊙ SN and ingestion of H into the He shell before the explosion. In these models a C- and Si-rich zone forms at the bottom of the He burning zone (C/Si zone). The region above the C/Si zone is termed the O/nova zone and exhibits the isotopic fingerprints of explosive H burning. Satisfactory fits of measured C-, N-, and Si-isotopic compositions and of 26Al/27Al ratios require small-scale mixing of matter originating from a region extending over 0.2 M⊙ for X and C grains and over 0.4 M⊙ for one of the putative nova grains, involving matter from a thin Si-rich layer slightly below the C/Si zone, the C/Si zone, and the O/nova zone. Simultaneous fitting of 14N/15N and 26Al/27Al requires a C-N fractionation of a factor of 50 during SiC condensation. This leads to preferential incorporation of radioactive 14C (half life 5700 yr) over directly produced 14N and can account for the 14N/15N along with 26Al/27Al ratios as observed in the SiC grains. The good fit for one of the putative nova grains along with its high 26Al/27Al points towards a SN origin and supports previous suggestions that some grains classified as nova grains might be from SNe

  14. Effect of pH on the electrical properties and conducting mechanism of SnO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Periathai, R.Sudha [Department of Physics, Standard Fireworks Rajaratnam College for Women, Sivakasi 626123 (India); Abarna, S.; Hirankumar, G. [Centre for Scientific and Applied Research, PSN College of Engineering and Technology, Tirunelveli 627152 (India); Jeyakumaran, N. [Department of Physics, V.H.N. Senthikumara Nadar College, Virudhunagar 626001 (India); Prithivikumaran, N., E-mail: janavi_p@yahoo.com [Department of Physics, V.H.N. Senthikumara Nadar College, Virudhunagar 626001 (India)

    2017-03-15

    Semiconductor nanoparticles have attracted more interests because of their size-dependent optical and electrical properties.SnO{sub 2} is an oxygen-deficient n-type semiconductor with a wide band gap of 3.6 eV (300 K). It has many remarkable applications as sensors, catalysts, transparent conducting electrodes, anode material for rechargeable Li- ion batteries and optoelectronic devices. In the present work, the role of pH in determining the electrical and dielectric properties of SnO{sub 2} nanoparticles has been studied as a function of temperature ranging from Room temperature (RT) to 114 °C in the frequency range of 7 MHz to 50 mHz using impedance spectroscopic technique. The non linear behavior observed in the thermal dependence of the conductance of SnO{sub 2} nanoparticles is explained by means of the surface property of SnO{sub 2} nanoparticles where proton hopping mechanism is dealt with. Jonscher's power law has been fitted for the conductance spectra and the frequency exponent (“s” value) gives an insight about the ac conducting mechanism. The temperature dependence of electrical relaxation phenomenon in the material has been observed. The complex electric modulus analysis indicates the possibility of hopping conduction mechanism in the system with non-exponential type of conductivity relaxation.

  15. Multi-quasiparticle excitation: Extending shape coexistence in A∼190 neutron-deficient nuclei

    International Nuclear Information System (INIS)

    Shi Yue; Liu, H. L.; Xu, F. R.; Walker, P. M.

    2010-01-01

    Multi-quasiparticle high-K states in neutron-deficient mercury, lead, and polonium isotopes have been investigated systematically by means of configuration-constrained potential-energy-surface calculations. An abundance of high-K states is predicted with both prolate and oblate shapes, which extends the shape coexistence of the mass region. Well-deformed shapes provide good conditions for the formation of isomers, as exemplified in 188 Pb. Of particular interest is the prediction of low-lying 10 - states in polonium isotopes, which indicate long-lived isomers.

  16. Stable and metastable equilibria in PbSe + SnI2=SnSe + PbI2

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Demidova, E.D.

    2003-01-01

    T-x-y phase diagrams of the PbSe + SnI 2 =SnSe + PbI 2 mutual system (stable states) are plotted for the first time. It is shown that melt, solid solutions on the base of components of the mutual system and phase on the base of Sn 2 SeI 4 take part in phase equilibria. Transformations in the PbSe + SnI 2 =SnSe + PbI 2 mutual system leading to crystallization of metastable polytype modifications of lead iodides and metastable ternary compound forming in PbSe-PbI 2 system are investigated for the first time [ru

  17. Synthesis of highly non-stoichiometric Cu{sub 2}ZnSnS{sub 4} nanoparticles with tunable bandgaps

    Energy Technology Data Exchange (ETDEWEB)

    Hamanaka, Yasushi, E-mail: hamanaka@nitech.ac.jp; Oyaizu, Wataru; Kawase, Masanari [Nagoya Institute of Technology, Department of Materials Science and Engineering (Japan); Kuzuya, Toshihiro [Muroran Institute of Technology, College of Design and Manufacturing Technology (Japan)

    2017-01-15

    Non-stoichiometric Cu{sub 2}ZnSnS{sub 4} nanoparticles with average diameters of 4–15 nm and quasi-polyhedral shape were successfully synthesized by a colloidal method. We found that a non-stoichiometric composition of Zn to Cu in Cu{sub 2}ZnSnS{sub 4} nanoparticles yielded a correlation where Zn content increased with a decrease in Cu content, suggesting formation of lattice defects relating to Cu and Zn, such as a Cu vacancy (V{sub Cu}), antisite with Zn replacing Cu (Zn{sub Cu}), and/or defect cluster of V{sub Cu} and Zn{sub Cu}. The bandgap energy of Cu{sub 2}ZnSnS{sub 4} nanoparticles systematically varies between 1.56 and 1.83 eV depending on the composition ratios of Cu and Zn, resulting in a wider bandgap for Cu-deficient Cu{sub 2}ZnSnS{sub 4} nanoparticles. These characteristics can be ascribed to the modification in electronic band structures due to formation of V{sub Cu} and Zn{sub Cu} on the analogy of ternary copper chalcogenide, chalcopyrite CuInSe{sub 2}, in which the top of the valence band shifts downward with decreasing Cu contents, because much like the structure of CuInSe{sub 2}, the top of the valence band is composed of a Cu 3d orbital in Cu{sub 2}ZnSnS{sub 4}.

  18. On Nuclear Molecules Built up from sup 1 sup 3 sup 2 Sn Components

    CERN Document Server

    Swiatecki, W J

    2003-01-01

    The possible existence of nuclear quasi-molecules built up from sup 1 sup 3 sup 2 Sn components is investigated. The crucial question is whether the extra stability of the doubly magic sup 1 sup 3 sup 2 Sn nuclei makes them sufficiently rigid to be able to withstand the strains imposed by their mutual interactions. It is argued that if the simplest quasi-molecular dumbbell configuration were found to be (meta-)stable, then triangular and even tetrahedral structures might have comparable barriers against disintegration and comparable spontaneous fission lifetimes. These are estimated using simplifying assumptions. As regards the dumbbell's stability, one may relate this to the existence of a potential energy pocket in the deformation energy landscape of a fissioning sup 2 sup 6 sup 4 Fm nucleus, and to the presence of ''bimodal'' fission in heavy Fm isotopes. Further experimental and theoretical studies of such systems may be relevant for answering the question concerning nuclear quasi-molecules.

  19. Dystrophin deficiency leads to disturbance of LAMP1-vesicle-associated protein secretion

    DEFF Research Database (Denmark)

    Duguez, S.; Duddy, W.; Johnston, H.

    2013-01-01

    Duchenne muscular dystrophy results from loss of the protein dystrophin, which links the intracellular cytoskeletal network with the extracellular matrix, but deficiency in this function does not fully explain the onset or progression of the disease. While some intracellular events involved...... in the degeneration of dystrophin-deficient muscle fibers have been well characterized, changes in their secretory profile are undescribed. To analyze the secretome profile of mdx myotubes independently of myonecrosis, we labeled the proteins of mdx and wild-type myotubes with stable isotope-labeled amino acids...

  20. Band Alignments, Valence Bands, and Core Levels in the Tin Sulfides SnS, SnS2, and Sn2S3: Experiment and Theory

    OpenAIRE

    Whittles, TJ; Burton, LA; Skelton, JM; Walsh, A; Veal, TD; Dhanak, VR

    2016-01-01

    Tin sulfide solar cells show relatively poor efficiencies despite attractive photovoltaic properties, and there is difficulty in identifying separate phases, which are also known to form during Cu2ZnSnS4 depositions. We present X-ray photoemission spectroscopy (XPS) and inverse photoemission spectroscopy measurements of single crystal SnS, SnS2, and Sn2S3, with electronic-structure calculations from density functional theory (DFT). Differences in the XPS spectra of the three phases, including...

  1. Comparative study of SnS recrystallization in molten CdI{sub 2}, SnCl{sub 2}and KI

    Energy Technology Data Exchange (ETDEWEB)

    Timmo, Kristi; Kauk-Kuusik, Marit; Pilvet, Maris; Mikli, Valdek; Kaerber, Erki; Raadik, Taavi; Leinemann, Inga; Altosaar, Mare; Raudoja, Jaan [Department of Materials Science, Tallinn University of Technology, Tallinn (Estonia)

    2016-01-15

    In the present study, the recrystallization of polycrystalline SnS in different molten salts CdI{sub 2}, SnCl{sub 2} and KI as flux materials are presented. The recrystallization and growth of polycrystalline material in molten salts produces unique SnS monograin powders usable in monograin layer solar cells. XRD and Raman analysis revealed that single phase SnS powder can be obtained in KI at 740 C and in SnCl{sub 2} at 500 C. Long time heating of SnS in molten CdI{sub 2} was accompanied by chemical interaction between SnS and CdI{sub 2} that resulted in a mixture of CdS and Sn{sub 2}S{sub 3} crystals. SEM images showed that morphology of crystals can be controlled by the nature of the flux materials: needle-like Sn{sub 2}S{sub 3} together with round edged crystals of CdS in CdI{sub 2}, flat crystals of SnS with smooth surfaces in SnCl{sub 2} and well-formed SnS crystals with rounded edges in KI had been formed. The temperatures of phase transitions and/or the interactions of SnS and flux materials were determined by differential thermal analysis. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Laser fluorescence on radio-active isotopes produced in very low yield

    International Nuclear Information System (INIS)

    Dancy, D.E.; Billowes, J.; Grant, I.S.; Evans, D.E.; Griffith, J.A.R.; Wells, S.A.; Eastham, D.A.; Groves, J.; Smith, J.R.H.; Tolfree, D.W.L.; Walker, P.M.

    1990-01-01

    Fast particle-photon coincidence techniques, developed at Daresbury with strontium isotopes, allow ultra-sensitive laser fluorescence spectroscopy of beams of radio-active isotopes which can only be produced in very low yields. The technique has now been applied to neutron-deficient barium isotopes down to 120 Ba. From measured hyperfine splitting and isotope shifts, nuclear moments and changes in mean square radii have been determined. The work has revealed an abrupt increase in the mean square radius for 121 Ba large enough to disrupt the systematic staggering of nuclear size seen for the series. In a recent experiment an isomeric state of 127 Ba with a half-life of about 2 seconds has been produced in a very low yield; nevertheless we have succeeded in obtaining a fluorescence spectrum. (orig.)

  3. PROTEUS-SN User Manual

    Energy Technology Data Exchange (ETDEWEB)

    Shemon, Emily R. [Argonne National Lab. (ANL), Argonne, IL (United States); Smith, Micheal A. [Argonne National Lab. (ANL), Argonne, IL (United States); Lee, Changho [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-16

    PROTEUS-SN is a three-dimensional, highly scalable, high-fidelity neutron transport code developed at Argonne National Laboratory. The code is applicable to all spectrum reactor transport calculations, particularly those in which a high degree of fidelity is needed either to represent spatial detail or to resolve solution gradients. PROTEUS-SN solves the second order formulation of the transport equation using the continuous Galerkin finite element method in space, the discrete ordinates approximation in angle, and the multigroup approximation in energy. PROTEUS-SN’s parallel methodology permits the efficient decomposition of the problem by both space and angle, permitting large problems to run efficiently on hundreds of thousands of cores. PROTEUS-SN can also be used in serial or on smaller compute clusters (10’s to 100’s of cores) for smaller homogenized problems, although it is generally more computationally expensive than traditional homogenized methodology codes. PROTEUS-SN has been used to model partially homogenized systems, where regions of interest are represented explicitly and other regions are homogenized to reduce the problem size and required computational resources. PROTEUS-SN solves forward and adjoint eigenvalue problems and permits both neutron upscattering and downscattering. An adiabatic kinetics option has recently been included for performing simple time-dependent calculations in addition to standard steady state calculations. PROTEUS-SN handles void and reflective boundary conditions. Multigroup cross sections can be generated externally using the MC2-3 fast reactor multigroup cross section generation code or internally using the cross section application programming interface (API) which can treat the subgroup or resonance table libraries. PROTEUS-SN is written in Fortran 90 and also includes C preprocessor definitions. The code links against the PETSc, METIS, HDF5, and MPICH libraries. It optionally links against the MOAB library and

  4. Continuation of Atomic Spectroscopy on Alkali Isotopes at ISOLDE

    CERN Multimedia

    2002-01-01

    Laser optical measurements on Rb, Cs and Fr have already been performed at ISOLDE in 1978-79. The hyperfine structure and isotope shift of |7|6|-|9|8Rb, |1|1|8|-|1|4|5Cs, |2|0|8|-|2|1|3Fr and 14 of their isomers have been studied. Among the wealth of information which has been obtained, the most important are the first observation of an optical transition of the element Fr, the evidence of the onset of nuclear deformation at N~=~60 for Rb isotopes and the shape isomerism isotopes. \\\\ \\\\ From both the atomic and nuclear physics point of view, new studies seem very promising: \\item - the search for new optical transitions in Fr; the shell effect in the rms charge radius at N~=~126 for Fr isotopes \\item - the study of a possible onset of deformation for Cs isotopes beyond |1|4|5Cs \\item - the study of a region of static deformation in neutron-deficient Rb isotopes. \\\\ \\\\ \\end{enumerate} A new apparatus has been built. The principle remains the same as used in our earlier experiments. The improvements concern ess...

  5. Search for unknown isotopes using the TIARA-ISOL and the JAERI-ISOL

    Energy Technology Data Exchange (ETDEWEB)

    Asai, Masato [Nagoya Univ. (Japan). School of Engineering

    1997-07-01

    The new neutron-deficient isotopes {sup 127}Pr and {sup 125}Pr, and the new neutron-rich isotopes {sup 166}Tb, {sup 165}Gd and {sup 161}Sm were identified using the TIARA-ISOL with {sup 36}Ar + {sup 92,94}Mo reactions, and the gas-jet coupled JAERI-ISOL with a proton-induced fission of {sup 238}U, respectively. The element-selective oxidation technique was used to reduce large contamination from isobars and molecular ions with production cross sections about one or two orders of magnitude as large as those of the new isotopes. The good signal-to-noise ratios achieved in the present measurements were essential to observe and identify weak X/{gamma} rays from the new isotopes. (author)

  6. GeSn growth kinetics in reduced pressure chemical vapor deposition from Ge2H6 and SnCl4

    Science.gov (United States)

    Aubin, J.; Hartmann, J. M.

    2018-01-01

    We have investigated the low temperature epitaxy of high Sn content GeSn alloys in a 200 mm industrial Reduced Pressure - Chemical Vapor Deposition tool from Applied Materials. Gaseous digermane (Ge2H6) and liquid tin tetrachloride (SnCl4) were used as the Ge and Sn precursors, respectively. The impact of temperature (in the 300-350 °C range), Ge2H6 and SnCl4 mass-flows on the GeSn growth kinetics at 100 Torr has been thoroughly explored. Be it at 300 °C or 325 °C, a linear GeSn growth rate increase together with a sub-linear Sn concentration increase occurred as the SnCl4 mass-flow increased, irrespective of the Ge2H6 mass flow (fixed or varying). The Sn atoms seemed to catalyze H desorption from the surface, resulting in higher GeSn growth rates for high SnCl4 mass-flows (in the 4-21 nm min-1 range). The evolution of the Sn content x with the F (SnCl4) 2 ·/F (Ge2H6) mass-flow ratio was fitted by x2/(1 - x) = n ·F (SnCl4) 2 ·/F (Ge2H6), with n = 0.25 (325 °C) and 0.60 (300 °C). We have otherwise studied the impact of temperature, in the 300-350 °C range, on the GeSn growth kinetics. The GeSn growth rate exponentially increased with the temperature, from 15 up to 32 nm min-1. The associated activation energy was low, i.e. Ea = 10 kcal mol-1. Meanwhile, the Sn content decreased linearly as the growth temperature increased, from 15% at 300 °C down to 6% at 350 °C.

  7. HPLC method for determination of SN-38 content and SN-38 entrapment efficiency in a novel liposome-based formulation, LE-SN38.

    Science.gov (United States)

    Xuan, Tong; Zhang, J Allen; Ahmad, Imran

    2006-05-03

    A simple HPLC method was developed for quantification of SN-38, 7-ethyl-10-hydroxycamptothecin, in a novel liposome-based formulation (LE-SN38). The chromatographic separation was achieved on an Agilent Zorbax SB-C18 (4.6 mmx250 mm, 5 microm) analytical column using a mobile phase consisting of a mixture of NaH2PO4 (pH 3.1, 25 mM) and acetonitrile (50:50, v/v). SN-38 was detected at UV wavelength of 265 nm and quantitatively determined using an external calibration method. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.05 and 0.25 microg/mL, respectively. The individual spike recovery of SN-38 ranged from 100 to 101%. The percent of relative standard deviation (%R.S.D.) of intra-day and inter-day analyses were less than 1.6%. The method validation results confirmed that the method is specific, linear, accurate, precise, robust and sensitive for its intended use. The current method was successfully applied to the determination of SN-38 content and drug entrapment efficiency in liposome-based formulation, LE-SN38 during early stage formulation development.

  8. Early onset of ground-state deformation in the neutron-deficient polonium isotopes

    CERN Document Server

    Cocolios, T E; Seliverstov, M D; Andreyev, A N; Antalic, S; Barzakh, A E; Bastin, B; Buscher, J; Darby, I G; Fedorov, D V; Fedosseyev, V N; Flanagan, K T; Franchoo, S; Fritzsche, S; Huber, G; Huyse, M; Keupers, M; Koster, U; Kudryavtsev, Yu; Mane, E; Marsh, B A; Molkanov, P L; Page, R D; Sjoedin, A M; Stefan, I; Van de Walle, J; Van Duppen, P; Venhart, M; Zemlyanoy, S G; Bender, M; Heenen, P H; 10.1103/PhysRevLett.106.052503

    2011-01-01

    In-source resonant ionization laser spectroscopy of the even-$A$ polonium isotopes $^{192-210,216,218}$Po has been performed using the $6p^37s$ $^5S_2$ to $6p^37p$ $^5P_2$ ($\\lambda=843.38$ nm) transition in the polonium atom (Po-I) at the CERN ISOLDE facility. The comparison of the measured isotope shifts in $^{200-210}$Po with a previous data set allows to test for the first time recent large-scale atomic calculations that are essential to extract the changes in the mean-square charge radius of the atomic nucleus. When going to lighter masses, a surprisingly large and early departure from sphericity is observed, which is only partly reproduced by Beyond Mean Field calculations.

  9. In Situ High-Resolution Transmission Electron Microscopy (TEM) Observation of Sn Nanoparticles on SnO2 Nanotubes Under Lithiation.

    Science.gov (United States)

    Cheong, Jun Young; Chang, Joon Ha; Kim, Sung Joo; Kim, Chanhoon; Seo, Hyeon Kook; Shin, Jae Won; Yuk, Jong Min; Lee, Jeong Yong; Kim, Il-Doo

    2017-12-01

    We trace Sn nanoparticles (NPs) produced from SnO2 nanotubes (NTs) during lithiation initialized by high energy e-beam irradiation. The growth dynamics of Sn NPs is visualized in liquid electrolytes by graphene liquid cell transmission electron microscopy. The observation reveals that Sn NPs grow on the surface of SnO2 NTs via coalescence and the final shape of agglomerated NPs is governed by surface energy of the Sn NPs and the interfacial energy between Sn NPs and SnO2 NTs. Our result will likely benefit more rational material design of the ideal interface for facile ion insertion.

  10. Lithium insertion mechanism in SnS2

    International Nuclear Information System (INIS)

    Lefebvre-Devos, I.; Olivier-Fourcade, J.; Jumas, J.C.; Lavela, P.

    2000-01-01

    We study lithium insertion in SnS 2 by means of 119 Sn Moessbauer spectroscopy, x-ray absorption spectroscopy at Sn L I,III , and S K edges, and theoretical electronic structures (calculated in the density-functional theory framework). An insertion mechanism is derived according to the Li amount. It shows the influence of the SnS 2 -layered structure on the Sn reduction, particularly the possibility of an intermediate oxidation state between Sn IV and Sn II , which is not observed during Li insertion in three-dimensional sulfides

  11. Sandwich-like C@SnO2/Sn/void@C hollow spheres as improved anode materials for lithium ion batteries

    Science.gov (United States)

    Wang, Huijun; Jiang, Xinya; Chai, Yaqin; Yang, Xia; Yuan, Ruo

    2018-03-01

    As lithium ion batteries (LIBs) anode, SnO2 suffers fast capacity fading due to its large volume expansion during discharge/charge process. To overcome the problem, sandwich-like C@SnO2/Sn/void@C hollow spheres (referred as C@SnO2/Sn/void@C HSs) are prepared by in-situ polymerization and carbonization, using hollow SnO2 as self-template and dopamine as carbon source. The C@SnO2/Sn/void@C HSs possesses the merits of hollow and core/void/shell structure, so that they can accommodate the volume change under discharge/charge process, shorten the transmission distance of Li ions, own more contact area for the electrolyte. Thanks to these advantages, C@SnO2/Sn/void@C HSs display excellent electrochemical performance as anode materials for LIBs, which deliver a high capacity of 786.7 mAh g-1 at the current density of 0.5 A g-1 after 60 cycles. The simple synthesis method for C@SnO2/Sn/void@C HSs with special structure will provide a promising method for preparing other anode materials for LIBs.

  12. Nuclear structure studies on indium and tin isotope chains by means of laser spectroscopy

    International Nuclear Information System (INIS)

    Eberz, J.

    1986-11-01

    In a collaboration with GSI in Darmstadt and ISOLDE in Geneva the hyperfine structure (HFS) and the isotope shift (IS) of the indium isotopes from 104 In - 127 In in their ground and isomeric states could be studied. Additionally the tin isotopes 109 Sn and 111 Sn could be measured. In tin the transition 5p 2 1 S 0 → 5p6s 3 P 1 with λ = 563 nm was studied. In indium the transition 5p 2 P 1/2 → 6s 2 S 1/2 with λ = 410 nm and 5p 2 P 3/2 → 6s 2 S 1/2 with λ = 451 nm could be measured. The magnetic dipole moments and electric quadrupole moments determined from the measurements of the HFS can be sufficiently explained in the framework of the single-particle model. From the moments the configurations and spins of the studied nuclear states can be stated. In 109 Sn the nuclear spin was determined to I = 5/2. The measurement of the IS in two lines in 108 In allowed regarding the coupling rules for nuclear moments the determination of the nuclear spin. The spin of the 40 m isomers of the 108m In can be stated to I = 2. The mean square nuclear charge radius exhibits a parabolic slope the quadratic part of which with a maximum in the shell center at N = 66 between the neutron numbers N = 50 and N = 82 can be understood as sum of contributions of a surface correlation, i.e. a quadrupole deformation as well as eventually present higher order terms or a change of the surface skin density. The deformation determinable by this description is both for tin and for indium essentially larger than the deformation from the B(E2) values of tin or from the intrinsic quadrupole moments in indium derived from the HFS. (orig./HSI) [de

  13. Sn surface-enriched Pt-Sn bimetallic nanoparticles as a selective and stable catalyst for propane dehydrogenation

    KAUST Repository

    Zhu, Haibo

    2014-12-01

    A new one pot, surfactant-free, synthetic route based on the surface organometallic chemistry (SOMC) concept has been developed for the synthesis of Sn surface-enriched Pt-Sn nanoparticles. Bu3SnH selectively reacts with [Pt]-H formed in situ at the surface of Pt nanoparticles, Pt NPs, obtained by reduction of K2PtCl4 by LiB(C2H5)3H. Chemical analysis, 1H MAS and 13C CP/MAS solid-state NMR as well as two-dimensional double-quantum (DQ) and triple-quantum (TQ) experiments show that organo-tin moieties Sn(n-C4H9) are chemically linked to the surface of Pt NPs to produce, in fine, after removal of most of the n-butyl fragment, bimetallic Pt-Sn nanoparticles. The Sn(n-CH2CH2CH2CH3) groups remaining at the surface are believed to stabilize the as-synthesized Pt-Sn NPs, enabling the bimetallic NPs to be well dispersed in THF. Additionally, the Pt-Sn nanoparticles can be supported on MgAl2O4 during the synthesis of the nanoparticles. Some of the Pt-Sn/MgAl2O4 catalyst thus prepared exhibits high activity in PROX of CO and an extremely high selectivity and stability in propane dehydrogenation to propylene. The enhanced activity in propane dehydrogenation is associated with the high concentration of inactive Sn at the surface of Pt nanoparticles which ”isolates” the active Pt atoms. This conclusion is confirmed by XRD, NMR, TEM, and XPS analysis.

  14. Microstructural investigation and SnO nanodefects in spray-pyrolyzed SnO2 thin films

    DEFF Research Database (Denmark)

    Thanachayanont, Chanchana; Yordsri, Visittapong; Boothroyd, Chris

    2011-01-01

    Spray pyrolysis is one of the most cost-effective methods to prepare SnO2 films due to its ability to deposit large uniform area, low fabrication cost, simplicity and low deposition temperature. Conventionally, scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) are routinely used...... diffraction (CBED). It was found that large grain-size vertically-aligned columnar SnO2 grains were formed after a few layers of small grain-size randomly oriented SnO2 grains. Moreover, CBED showed the presence of SnO nanodefects that had not been reported before and could not be detected by SEM or XRD....

  15. Fluid sensitive nanoscale switching with quantum levitation controlled by $\\alpha$-Sn/$\\beta$-Sn phase transition

    OpenAIRE

    Boström, Mathias; Dou, Maofeng; Malyi, Oleksandr I.; Parashar, Prachi; Parsons, Drew F.; Brevik, Iver; Persson, Clas

    2018-01-01

    We analyze the Lifshitz pressure between silica and tin separated by a liquid mixture of bromobenzene and chlorobenzene. We show that the phase transition from semimetallic α−Sn to metallic β−Sn can switch Lifshitz forces from repulsive to attractive. This effect is caused by the difference in dielectric functions of α−Sn and β−Sn, giving both attractive and repulsive contributions to the total Lifshitz pressure in different frequency regions controlled by the composition of the intervening l...

  16. 99mTc bone scanning agents preparation and chemical analysis of Tc(Sn)pyrophosphate, Tc(Sn)MDP and Tc(Sn)HMDP

    International Nuclear Information System (INIS)

    Kroesbergen, J.

    1986-01-01

    This thesis describes a comparison of the preparation, composition and properties of three bone scanning agents: 99m Tc(Sn)pyrophosphate, 99m Tc(Sn)MDP and 99m Tc(Sn)HMDP. This study has been performed for two reasons: First to investigate the preparation and composition of the radiopharmaceuticals as a function of experimental conditions. Together with previously reported results for 99m Tc(Sn)EHDP, obtained in a similar way, this enables to use well-defined preparations of the bone scanning agents. Secondly to gain an insight in the mechanism in which the agents behave 'in vivo'. Because the 'in vivo' process is too complicated to study directly, it seemed more appropriate to perform 'in vitro' investigations as simplifications of the 'in vivo' situation. 304 refs.; 26 figs.; 31 tabs

  17. Laser-spectroscopic nuclear-structure studies on radioactive silver and indium isotopes

    International Nuclear Information System (INIS)

    Dinger, U.

    1988-05-01

    Neutron-deficient silver and neutron-rich indium isotopes were studied by collinear laser spectroscopy. The neutron-deficient nuclei 101 , 103 , 104 , 105 , 105m , 106m Ag were produced as evaporation-residual nuclei in heavy-ion fusion reactions at the mass separator of the GSI in Darmstadt. The fourteen studied indium isotopes and isomers with even mass number in the range 112-126 In were produced by 600-MeV-proton induced fission of a uranium carbide target at the ISOLDE separator in Geneva. The mass-separated ion beam was subsequently deviated electrostatically, neutralized in a sodium vapor and superposed with a c w dye laser. A photon counting system detected the resonance fluorescence of the induced transitions. The hyperfine structure and the isotope shift of the 4d 9 5s 2 2 D 5/2 → 4d 10 6p 2 P 3/2 transition (λ=547.7 nm) in silver and the 5p 2 P 1/2,3/2 → 6s 2 s 1/2 transition (λ=410 respectively 451 nm) in indium were measured. While in indium for the analysis of the data earlier work could be referred to, in silver a detailed analysis of the isotope shift and hyperfine structure was performed by means of ab initio calculations and semi-empirical procedures. Thereby the configuration interactions were especially considered. The nuclear moments were discussed in the framework of existing nuclear models regarding nuclear-spectroscopic informations. (orig./HSI) [de

  18. Measurements of electric quadrupole moments of neutron-deficient Au, Pt, and Ir nuclei with NMR-ON in hcp-Co

    CERN Multimedia

    Smolic, E; Hagn, E; Zech, E; Seewald, G

    2002-01-01

    The aim of the experiments is the measurement of $\\,$i) nuclear magnetic moments and electric quadrupole moments of neutron-deficient isotopes in the region Os-Ir-Pt-Au with the methods of quadrupole-interaction-resolved NMR on oriented nuclei " QI-NMR-ON " and modulated adiabatic passage on oriented nuclei " MAPON " and $\\,$ii) the magnetic hyperfine field, electric field gradient (EFG), and spin-lattice relaxation of 5d elements in ferromagnetic Fe, Ni, fcc-Co and hcp-Co.\\\\ The measurements on Au isotopes have been finished successfully. The quadrupole moments of $^{186}$Au, $^{193m}$Au, $^{195}$Au, $^{195m}$Au, $^{197m}$Au, $^{198}$Au and $^{199}$Au were determined with high precision.\\\\ For neutron-deficient Ir isotopes QI-NMR-ON measurements were performed after implantation of Hg precursors. The EFG of Ir in hcp-Co has been calibrated. Thus precise values for the spectroscopic quadrupole mo...

  19. Electronic and magnetic properties of rare earth-Sn3 compounds for 119Sn Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sanchez, J.P.; Friedt, J.M.; Shenoy, G.K.; Percheron, A.; Achard, J.C.

    1975-01-01

    The electronic and magnetic properties of RESn 3 compounds (RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Yb) have been investigated using the 23.8keV Moessbauer resonance of 119 Sn. The isomer shifts and quadrupole interactions are nearly the same in all compounds. The transferred magnetic fields and their orientation with respect to the principal electric field gradient axis at various Sn sites in the magnetically ordered state of RESn 3 (RE=Pr, Nd, Sm, Eu, Gd) have been utilized to get information about the magnetic structure. An evaluation of the transferred fields in PrSn 3 and NdSn 3 shows that the spin density at the Sn nucleus is nearly the same in both compounds [fr

  20. The tin-rich copper lithium stannides: Li3Cu6Sn4 and Li2CuSn2

    International Nuclear Information System (INIS)

    Fuertauer, Siegfried; Flandorfer, Hans; Effenberger, Herta S.

    2015-01-01

    The Sn rich ternary intermetallic compounds Li 3 Cu 6 Sn 4 (CSD-427097) and Li 2 CuSn 2 (CSD-427098) were synthesized from the pure elements by induction melting and annealing at 400 C. Structural investigations were performed by powder- and single-crystal XRD. Li 3 Cu 6 Sn 4 crystallizes in space group P6/mmm; it is structurally related to but not isotypic with MgFe 6 Ge 6 (a = 5.095(2) Aa, c = 9.524(3) Aa; wR 2 = 0.059; 239 unique F 2 -values, 17 free variables). Li 3 Cu 6 Sn 4 is characterized by two sites with a mixed Cu:Sn occupation. In contrast to all other Cu-Li-Sn compounds known so far, any mixed occupation was found for Cu-Li pairs only. In addition, one Li site is only half occupied. The second Sn rich phase is Li 2 CuSn 2 (space group I4 1 /amd, a = 4.4281(15) Aa, c = 19.416(4) Aa; wR 2 = 0.033; 213 unique F 2 -values, 12 atom free variables); it is the only phase in the Cu-Li-Sn system which is noted for full ordering. Both crystal structures exhibit 3D-networks which host Li atoms in channels. They are important for understanding the lithiation mechanism in Cu-Sn electrodes for Li-ion batteries.

  1. SN REFSDAL: CLASSIFICATION AS A LUMINOUS AND BLUE SN 1987A-LIKE TYPE II SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, P. L.; Filippenko, A. V.; Graham, M. L. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Brammer, G.; Strolger, L.-G.; Riess, A. G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Selsing, J.; Hjorth, J.; Christensen, L. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Foley, R. J. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, IL 61801 (United States); Rodney, S. A. [Department of Physics and Astronomy, University of South Carolina, 712 Main St., Columbia, SC 29208 (United States); Treu, T. [University of California, Los Angeles, CA 90095 (United States); Steidel, C. C.; Strom, A.; Zitrin, A. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Schmidt, K. B.; McCully, C. [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Bradač, M. [University of California, Davis, 1 Shields Avenue, Davis, CA 95616 (United States); Jha, S. W. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Graur, O., E-mail: pkelly@astro.berkeley.edu [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States); and others

    2016-11-10

    We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a broad H α P-Cygni profile and Na I D absorption in the HST grism spectrum at the redshift ( z = 1.49) of the spiral host galaxy. SNe IIn, largely powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong H α and Na I D absorption. From the grism spectrum, we measure an H α expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the H α emission of the WFC3 and X-shooter spectra, separated by ∼2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, photometry of SN Refsdal favors bluer B - V and V - R colors and one of the largest luminosities for the assumed range of potential magnifications. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material. Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3 ± 0.1 dex and <8.4 dex, respectively) near the explosion site.

  2. Preparation of PtSnCu/C and PtSn/C electrocatalysts and activation by dealloying processes for ethanol electrooxidation; Preparacao de eletrocatalisadores PtSnCu/C e PtSn/C e ativacao por processos de dealloying para aplicacao na oxidacao eletroquuimica do etanol

    Energy Technology Data Exchange (ETDEWEB)

    Crisafulli, Rudy

    2013-06-01

    PtSnCu/C (with different Pt:Sn:Cu atomic ratios) and PtSn/C (50:50) electrocatalysts were prepared by borohydride (BR) and alcohol-reduction (AR) processes using H{sub 2}PtCl{sub 6}.6H{sub 2}O, SnCl{sub 2}.2H{sub 2}O and CuCl{sub 2}.2H{sub 2}O as metal sources, NaBH{sub 4} and ethylene glycol as reducing agents, 2-propanol and ethylene glycol/water as solvents and carbon black as support. In a further step, these electrocatalysts were activated by chemical (CD) and electrochemical (ED) dealloying processes through acid treatment and thin porous coating technique, respectively. These materials were characterized by energy dispersive X-ray, Xray diffraction, transmission electron microscopy, line scan energy dispersive Xray and cyclic voltammetry. Electrochemical studies for ethanol electro-oxidation were performed by cyclic voltammetry, chronoamperometry and in single Direct Ethanol Fuel Cell using Membrane Electrode Assembly (MEA). The anodic effluents were analysed by gas chromatography. The X-ray diffractograms of the as-synthesized electrocatalysts showed the typical face-centered cubic structure (FCC) of platinum and its alloys. After dealloying, the X-ray diffractograms showed that the Pt FCC structure was preserved. The crystallite sizes of the assynthesized electrocatalysts were in the range of <=2 nm to 3 nm and after dealloying there were no significant variations in sizes. The energy dispersive Xray analysis of the as-synthesized electrocatalysts showed a Pt:Sn and Pt:Sn:Cu atomic ratios similar to the nominal values. After chemical and electrochemical dealloying of the electrocatalysts the ranged Pt:Sn and Pt:Sn:Cu atomic ratios showed that Cu and Sn atoms were removed. However, chemical dealloying process proved to be more efficient for removing Cu and electrochemical dealloying for removing Sn. The line scan energy dispersive X-ray analysis showed that acid and electrochemical treatments were efficient to dealloying Cu and/or Sn superficial atoms of

  3. Nuclear shape staggering in very neutron deficient Hg isotopes detected by laser spectroscopy

    International Nuclear Information System (INIS)

    Dabkiewicz, P.; Duke, C.; Fischer, H.; Kuehl, T.; Kluge, H.-J.

    1978-01-01

    The isotope shift in the lambda = 2537 A line of the even isotopes 206 Hg, 190 Hg, 188 Hg, 186 Hg, 184 Hg as well as of the I = 13/2 isomers of 191 Hg, 189 Hg, 187 Hg, 185 Hg has been measured by use of a tunable dye laser at the on-line masseparator ISOLDE at CERN. The resulting delta 2 > values follow the line, extrapolated from the chain 205 Hg- 187 Hg which is known to have spherical nuclear shape at the heavy end changing smoothly to slight oblate deformation for the lighter isotopes. Previous measurements of the I = 1/2 groundstates of 181 Hg. 183 Hg and 185 Hg revealed a sharp shape transition to strong deformation. Combined with the new results the following effects can be proved for the first time from the model-independent quantity delta 2 >: 1) the existence of odd even-shape staggering, 2) the coexistence of very different shapes in one and the same nucleus as manifested by the huge isomer shift in 185 Hg, 3) the absence of mixing of the different shapes. (author)

  4. Magnetic property and Mössbauer analysis of SrSn{sub 1−x}Fe{sub x}O{sub 3} prepared by a sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Kiyoshi, E-mail: dqf10204@nifty.com [Tokyo University of Science, Photocatalysis International Research Center (Japan); Suzuki, Shigeyo; Koike, Yuya [Meiji University, Department of Science and Engineering (Japan); Li, Hongling [The University of Tokyo, Graduate School of Engineering (Japan); Okazawa, Atsushi [The University of Tokyo, Graduate School of Arts and Sciences (Japan); Kojima, Norimichi [Toyota Physical and Chemical Research Institute (Japan)

    2016-12-15

    The dilute magnetic properties of SrSn{sub 1−x}Fe{sub x}O{sub 3} (x = 0.01 − 0.15) prepared by sol-gel and thermal decomposition methods were investigated by {sup 57}Fe Mössbauer spectrometry, magnetometry, and X-ray diffractometry. It was found that SrSnO{sub 3} doped with 2–8 % Fe show weak ferromagnetism although only paramagnetic doublets are observed in {sup 57}Fe Mössbauer spectra at room temperature (RT), whereas SrSnO{sub 3} doped with 10–15 % Fe show relatively strong ferromagnetism, and the sextets are additionally observed in the {sup 57}Fe Mössbauer spectra at RT. The weak ferromagnetism by doping 2–8 % Fe is considered to be caused by the induced magnetic defects, and the ferromagnetism by doping 10–15 % Fe are considered mainly due to the magnetic coupling between dilute Fe {sup 3+} partially substituted at Sn {sup 4+} sites in the orthorhombic structure of SrSnO{sub 3−δ} accompanying the oxygen deficiencies. It is further remarkable that poor crystalline 8 % Fe doped SrSnO{sub 3−δ} obtained by annealing at 600 {sup ∘}C shows relatively high saturation magnetization and low coercivity.

  5. Polarographic determination of Sn (II) and total Sn in PYRO and MDP radiopharmaceutical kits

    International Nuclear Information System (INIS)

    Sebastian, Maria V.A.; Lugon, Marcelo Di M.V.; Silva, Jose L. da; Fukumori, Neuza T.O.; Pereira, Nilda P.S. de; Silva, Constancia P.G. da; Matsuda, Margareth M.N.

    2007-01-01

    A sensitive, alternative method to atom absorption spectrometry, fluorimetry or potentiometry for the evaluation of tin(II) ions (0.1- 10 mg) and total tin in radiopharmaceutical kits was investigated. Differential pulse polarography was chosen. The supporting electrolyte was H 2 SO 4 3 mol L -1 and HCl 3 mol L -1 solution. The potential was swept from -250 to -800 mV vs Ag/AgCl/saturated KCl, using a dropping mercury electrode with 1 s drop time, 50 mV s -1 scan rate, -50 mV pulse amplitude, 40 ms pulse time and 10 mV step amplitude. Pure nitrogen was used to deaerate the polarographic cell solution for 5 min, before and after each sample introduction. Oxidation of Sn(II) was made in the same sample vial by adding H 2 O 2 (hydrogen peroxide) 10 mol L -1 , at 37 deg C, in order to quantify the total Sn. The calibration curve for Sn(II) and Sn(IV) was obtained in the concentration range of 0-10 ppm from a 1000 ppm standard solution. The detection limit of Sn(II) is 0.5 ppm and for Sn(IV) is 0.6 ppm. Differential pulse polarography was performed in the pyrophosphate (PYRO) and methylenediphosphonic acid (MDP) radiopharmaceutical kits, containing 2 mg and 1 mg of SnCl 2 .2H 2 O per vial, respectively. The described method for determination of stannous ion (Sn(II)), is selective, reproducible and adequate to be used in the quality control of lyophilized reagents and it shall be performed for other cold kits produced at IPEN. (author)

  6. Accelerator based production of auger-electron-emitting isotopes for radionuclide therapy

    International Nuclear Information System (INIS)

    Thisgaard, H.

    2008-08-01

    In this research project the focus has been on the identification and production of new, unconventional Auger-electron-emitting isotopes for targeted radionuclide therapy of cancer. Based on 1st principles dosimetry calculations on the subcellular level, the Auger-emitter 119Sb has been identified as a potent candidate for therapy. The corresponding imaging analogue 117Sb has been shown from planar scintigraphy and single-photon emission computed tomography (SPECT) to be suitable for SPECT-based dosimetry of a future Sb-labeled radiopharmaceutical. The production method of these radioisotopes has been developed using a low-energy cyclotron via the nuclear reactions 119Sn(p,n)119Sb and 117Sn(p,n)117Sb including measurements of the excitation function for the former reaction. Moreover, a new high-yield radiochemical separation method has been developed to allow the subsequent separation of the produced 119Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron, two new 'High Power' cyclotron targets were developed in this study. The target development was primarily based on theoretical thermal modeling calculations using finite-element-analysis software. With these targets, I have shown that it will be possible to produce several tens of GBq of therapeutics isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able to experimentally evaluate and compare the potency of the new and unconventional Auger-emitters (e.g. 119Sb). However, due to experimental complications, the development of this

  7. Accelerator based production of auger-electron-emitting isotopes for radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thisgaard, H.

    2008-08-15

    In this research project the focus has been on the identification and production of new, unconventional Auger-electron-emitting isotopes for targeted radionuclide therapy of cancer. Based on 1st principles dosimetry calculations on the subcellular level, the Auger-emitter 119Sb has been identified as a potent candidate for therapy. The corresponding imaging analogue 117Sb has been shown from planar scintigraphy and single-photon emission computed tomography (SPECT) to be suitable for SPECT-based dosimetry of a future Sb-labeled radiopharmaceutical. The production method of these radioisotopes has been developed using a low-energy cyclotron via the nuclear reactions 119Sn(p,n)119Sb and 117Sn(p,n)117Sb including measurements of the excitation function for the former reaction. Moreover, a new high-yield radiochemical separation method has been developed to allow the subsequent separation of the produced 119Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron, two new 'High Power' cyclotron targets were developed in this study. The target development was primarily based on theoretical thermal modeling calculations using finite-element-analysis software. With these targets, I have shown that it will be possible to produce several tens of GBq of therapeutics isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able to experimentally evaluate and compare the potency of the new and unconventional Auger-emitters (e.g. 119Sb). However, due to experimental complications, the development

  8. Internal friction behavior of liquid Bi-Sn alloys

    International Nuclear Information System (INIS)

    Wu Aiqing; Guo Lijun; Liu Changsong; Jia Erguang; Zhu Zhengang

    2005-01-01

    Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480 - bar Cand another at about 830 - bar C. Only a single internal-friction peak at about 830 - bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids

  9. Internal friction behavior of liquid Bi-Sn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wu Aiqing [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Guo Lijun [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Liu Changsong [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Jia Erguang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Zhu Zhengang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China)]. E-mail: zgzhu@issp.ac.cn

    2005-12-01

    Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480{sup -}bar Cand another at about 830{sup -}bar C. Only a single internal-friction peak at about 830{sup -}bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids.

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

    Science.gov (United States)

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

    2015-11-01

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

  11. Observing the Bose-condensation of Cooper's pairs in superconductors on the isotope 73(73Ge)

    International Nuclear Information System (INIS)

    Nemov, S.A.; Seregin, P.P.; Khujakulov, E.S.; Turaev, N.Yu.

    2007-01-01

    Using the emission Moessbauer spectroscopy method on the isotope 73 ( 73 Ge) it has been established that the superconducting transition in the solid solutions (Pb 1-x Sn x ) 1-z In z Te and superconductor Nb 3 Al leads to the change of the electron density in the metal sites, while in the anion sites no change in the electronic density has been observed. (author)

  12. STRESS a SN survey at ESO

    Science.gov (United States)

    Botticella, M. T.

    We performed the Southern inTermediate Redshift ESO Supernova Search (STRESS), a survey specifically designed to measure the rate of both SNe Ia and CC SNe, in order to obtain a direct comparison of the high redshift and local rates and to investigate the dependence of the rates on specific galaxy properties, most notably their colour. We found that the type Ia SN rate, at mean redshift z = 0.3, is 0.22+0.10+0.16-0.08-0.14 h270 SNu, while the CC SN rate, at z = 0.21, is 0.82+0.31+0.300.24-0.26 h270 SNu. The quoted errors are the statistical and systematic uncertainties. With respect to the local value, the CC SN rate at z = 0.2 is higher by a factor of ˜ 2, whereas the type Ia SN rate remains almost constant. We also measured the SN rates in the red and blue galaxies and found that the SN Ia rate seems to be constant in galaxies of different colour, whereas the CC SN rate seems to peak in blue galaxies, as in the local Universe. Finally we exploited the link between SFH and SN rates to predict the evolutionary behaviour of the SN rates and compare it with the path indicated by observations.

  13. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    Directory of Open Access Journals (Sweden)

    Cuong D. Tran

    2015-05-01

    Full Text Available It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

  14. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    Science.gov (United States)

    Tran, Cuong D.; Gopalsamy, Geetha L.; Mortimer, Elissa K.; Young, Graeme P.

    2015-01-01

    It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease. PMID:26035248

  15. Sn whiskers removed by energy photo flashing

    International Nuclear Information System (INIS)

    Jiang, N.; Yang, M.; Novak, J.; Igor, P.; Osterman, M.

    2012-01-01

    Highlights: ► Sn whiskers were sintered by intense light flashing (Photosintering). ► Photosintering can effectively eliminate Sn whiskers. ► Photosintering would not damage electronic devices. ► Photosintering is a very promising approach to improve Sn-based electronic surface termination. - Abstract: Sn whiskers have been known to be the major issue resulting in electronic circuit shorts. In this study, we present a novel energy photo flashing approach (photosintering) to shorten and eliminate Sn whiskers. It has been found that photosintering is very effective to modify and remove Sn whiskers; only a sub-millisecond duration photosintering can amazingly get rid of over 90 vol.% of Sn whiskers. Moreover, this photosintering approach has also been proved to cause no damages to electronic devices, suggesting it is a potentially promising way to improve Sn-based electronic surface termination.

  16. Li2SnO3 derived secondary Li-Sn alloy electrode for lithium-ion batteries

    International Nuclear Information System (INIS)

    Zhang, D.W.; Zhang, S.Q.; Jin, Y.; Yi, T.H.; Xie, S.; Chen, C.H.

    2006-01-01

    As a possible high-capacity Li-ion battery anode material, Li 2 SnO 3 was prepared via a solid-state reaction route and a sol-gel route, separately. Its electrochemical performance was tested in coin-type cells with metallic Li as the counter electrode. The results show that the sol-gel derived Li 2 SnO 3 has uniform nano-sized particles (200-300 nm) and can deliver a better reversible capacity (380 mAh/g after 50 cycles in the voltage window of 0-1 V) than that from the solid-state reaction route. The characterizations by means of galvanostatic cycling, cyclic voltammetry and ex situ X-ray diffraction indicate that the electrochemical process of the Li 2 SnO 3 lithiation proceeds with an initial structural reduction of the composite oxide into Sn-metal and Li 2 O followed by a reversible Li-Sn alloy formation in the Li 2 O matrix. Due to the buffer role of the Li 2 O matrix, the reversibility of the secondary Li-Sn alloy electrode is largely secured

  17. Improving cycle stability of SnS anode for sodium-ion batteries by limiting Sn agglomeration

    Science.gov (United States)

    Wang, Wenhui; Shi, Liang; Lan, Danni; Li, Quan

    2018-02-01

    Flower-like SnS nanostructures are obtained by a simple solvothermal method for anode applications in Na-ion batteries. We show experimental evidence of progressive Sn agglomeration and crystalline Na2S enrichment at the end of de-sodiation process of the SnS electrode, both of which contribute to the capacity decay of the electrode upon repeated cycles. By replacing the commonly adopted acetylene black conductive additive with multi-wall carbon nanotubes (MWCNT), the cycle stability of the SnS electrode is largely improved, which correlates well with the observed suppression of both Sn agglomeration and Na2S enrichment at the end of de-sodiation cycle. A full cell is assembled with the SnS/MWCNT anode and the P2-Na2/3Ni1/3Mn1/2Ti1/6O2 cathode. An initial energy density of 262 Wh/kg (normalized to the total mass of cathode and anode) is demonstrated for the full cell, which retains 71% of the first discharge capacity after 40 cycles.

  18. Interfacial Bonding Energy on the Interface between ZChSnSb/Sn Alloy Layer and Steel Body at Microscale

    Directory of Open Access Journals (Sweden)

    Jianmei Wang

    2017-09-01

    Full Text Available To investigate the performance of bonding on the interface between ZChSnSb/Sn and steel body, the interfacial bonding energy on the interface of a ZChSnSb/Sn alloy layer and the steel body with or without Sn as an intermediate layer was calculated under the same loadcase using the molecular dynamics simulation software Materials Studio by ACCELRYS, and the interfacial bonding energy under different Babbitt thicknesses was compared. The results show that the bonding energy of the interface with Sn as an intermediate layer is 10% larger than that of the interface without a Sn layer. The interfacial bonding performances of Babbitt and the steel body with Sn as an intermediate layer are better than those of an interface without a Sn layer. When the thickness of the Babbitt layer of bushing is 17.143 Å, the interfacial bonding energy reaches the maximum, and the interfacial bonding performance is optimum. These findings illustrate the bonding mechanism of the interfacial structure from the molecular level so as to ensure the good bonding properties of the interface, which provides a reference for the improvement of the bush manufacturing process from the microscopic point of view.

  19. Interfacial Bonding Energy on the Interface between ZChSnSb/Sn Alloy Layer and Steel Body at Microscale.

    Science.gov (United States)

    Wang, Jianmei; Xia, Quanzhi; Ma, Yang; Meng, Fanning; Liang, Yinan; Li, Zhixiong

    2017-09-25

    To investigate the performance of bonding on the interface between ZChSnSb/Sn and steel body, the interfacial bonding energy on the interface of a ZChSnSb/Sn alloy layer and the steel body with or without Sn as an intermediate layer was calculated under the same loadcase using the molecular dynamics simulation software Materials Studio by ACCELRYS, and the interfacial bonding energy under different Babbitt thicknesses was compared. The results show that the bonding energy of the interface with Sn as an intermediate layer is 10% larger than that of the interface without a Sn layer. The interfacial bonding performances of Babbitt and the steel body with Sn as an intermediate layer are better than those of an interface without a Sn layer. When the thickness of the Babbitt layer of bushing is 17.143 Å, the interfacial bonding energy reaches the maximum, and the interfacial bonding performance is optimum. These findings illustrate the bonding mechanism of the interfacial structure from the molecular level so as to ensure the good bonding properties of the interface, which provides a reference for the improvement of the bush manufacturing process from the microscopic point of view.

  20. Can a sponge fractionate isotopes?

    Science.gov (United States)

    Patel, B; Patel, S; Balani, M C

    1985-03-22

    The study has unequivocally demonstrated that siliceous sponges Spirastrella cuspidifera and Prostylyssa foetida from the same microecological niche exhibit a high degree of species specificity, while accumulating a host of heavy metal ions (Ni, Cr, Cd, Sn, Ti, Mo, Zr). S. cuspidifera accumulated, in addition, 60Co and 63Ni, showing discrimination against other radionuclides, 137Cs and 131I, present in the ambient waters receiving controlled low level waste discharges from a B.W.R. nuclear power station. P. foetida, on the other hand, accumulated only 131I and showed discrimination against other radionuclides including 60Co, although the stable iodine concentrations in both the sponges were the same. The specific activity of 60Co (in becquerels per gram of 59Co) in S. cuspidifera and 131I (in becquerels per gram of 127I) in P. foetida were at least two orders of magnitude greater than in the ambient sea water. That of 63Ni (in becquerels per gram of 62Ni) in S. cuspidifera, on the other hand, was lower by two orders of magnitude than in either abiotic matrices from the same environment. Thus, not only did both the species show bioaccumulation of a specific element, but also preferential uptake of isotopes of the same element, though they were equally available for intake. Such differential uptake of isotopes can possibly be explained in terms of two quite different mechanisms operating, each applicable in a particular case. One is that the xenobiotic isotope enters the environment in a physicochemical form or as a complex different from that of its natural counterpart. If equilibration with the latter is slow, so that the organism acquires the xenobiotic in an unfamiliar chemical context, it may treat it as a chemically distinct entity so that its concentration factor differs from that of stable isotope, thus changing the specific activity. Alternatively, if the xenobiotic is present in the same chemical form as the stable isotope, the only way in which specific

  1. Electronic structure and isomer shifts of Sn halides

    International Nuclear Information System (INIS)

    Terra, J.; Guenzburger, D.

    1988-01-01

    The all-electron first-principles Discrete Variational method was employed to study the electronic structure of SnF 4 , SnCl 4 , SnBr 4 and SnI 4 . Values of the electronic density at the Sn nucleus were derived and related to 119 Sn Isomer Shifts to obtain the nuclear constant Δ 2 >. Differences in values of ρ(o) area discussed in terms of the chemical bonding between Sn and halogen atoms. (author) [pt

  2. 195Pt and 119Sn Knight shifts of U3Pt3Sn4

    International Nuclear Information System (INIS)

    Kojima, K.; Takabatake, T.; Harada, A.; Hihara, T.

    1995-01-01

    The 195 Pt and 119 Sn Knight shifts in U 3 Pt 3 Sn 4 have been measured in the temperature range 4.2-298K. They exhibit Curie-Weiss like behaviors above about 50K and remain constant below about 10K. This suggests that the deviation of χ(T) from the modified Curie-Weiss law is an intrinsic property of U 3 Pt 3 Sn 4 . ((orig.))

  3. The atomic structure of protons and hydrides in Sm1.92Ca0.08Sn2O7-δ pyrochlore from DFT calculations and FTIR spectroscopy

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Eurenius, K. E. J.; Rossmeisl, Jan

    2012-01-01

    A combined density functional theory and Fourier transform infrared spectroscopy study of the structure and specific site preference of protons and hydrides in the pyrochlore Sm1.92Ca0.08Sn2O7-δ is presented. Two protonic sites of particular high stability are identified, both located on O(1......) oxygen atoms closely associated with a Ca dopant. Further, the unexpected presence of Ho hydride defects in undoped, oxygen deficient Sm2Sn2O7 is reported. Finally, the stretching frequencies and relative intensities for these and other sites are calculated. The main features of the Fourier transform...

  4. Solid Liquid Interdiffusion Bonding of (Pb, Sn)Te Thermoelectric Modules with Cu Electrodes Using a Thin-Film Sn Interlayer

    Science.gov (United States)

    Chuang, T. H.; Lin, H. J.; Chuang, C. H.; Yeh, W. T.; Hwang, J. D.; Chu, H. S.

    2014-12-01

    A (Pb, Sn)Te thermoelectric element plated with a Ni barrier layer and a Ag reaction layer has been joined with a Cu electrode coated with Ag and Sn thin films using a solid-liquid interdiffusion bonding method. This method allows the interfacial reaction between Ag and Sn such that Ag3Sn intermetallic compounds form at low temperature and are stable at high temperature. In this study, the bonding strength was about 6.6 MPa, and the specimens fractured along the interface between the (Pb, Sn)Te thermoelectric element and the Ni barrier layer. Pre-electroplating a film of Sn with a thickness of about 1 μm on the thermoelectric element and pre-heating at 250°C for 3 min ensures the adhesion between the thermoelectric material and the Ni barrier layer. The bonding strength is thus increased to a maximal value of 12.2 MPa, and most of the fractures occur inside the thermoelectric material. During the bonding process, not only the Ag3Sn intermetallics but also Cu6Sn5 forms at the Ag3Sn/Cu interface, which transforms into Cu3Sn with increases in the bonding temperature or bonding time.

  5. Direct mass measurements of neutron-deficient xenon isotopes using the ISOLTRAP mass spectrometer

    CERN Document Server

    Dilling, J; Beck, D; Bollen, G; Herfurth, F; Kellerbauer, A G; Kluge, H J; Moore, R B; Scheidenberger, C; Schwarz, S; Sikler, G

    2004-01-01

    The masses of the noble-gas Xe isotopes with 114 $\\leq$ A $\\leq$ 123 have been directly measured for the first time. The experiments were carried out with the ISOLTRAP triple trap spectrometer at the online mass separator ISOLDE/CERN. A mass resolving power of the Penning trap spectrometer of $m/\\Delta m$ of close to a million was chosen resulting in an accuracy of $\\delta m \\leq 13$ keV for all investigated isotopes. Conflicts with existing, indirectly obtained, mass data by several standard deviations were found and are discussed. An atomic mass evaluation has been performed and the results are compared to information from laser spectroscopy experiments and to recent calculations employing an interacting boson model.

  6. Fluid-sensitive nanoscale switching with quantum levitation controlled by α -Sn/β -Sn phase transition

    Science.gov (United States)

    Boström, Mathias; Dou, Maofeng; Malyi, Oleksandr I.; Parashar, Prachi; Parsons, Drew F.; Brevik, Iver; Persson, Clas

    2018-03-01

    We analyze the Lifshitz pressure between silica and tin separated by a liquid mixture of bromobenzene and chlorobenzene. We show that the phase transition from semimetallic α -Sn to metallic β -Sn can switch Lifshitz forces from repulsive to attractive. This effect is caused by the difference in dielectric functions of α -Sn and β -Sn , giving both attractive and repulsive contributions to the total Lifshitz pressure in different frequency regions controlled by the composition of the intervening liquid mixture. In this way, one may be able to produce phase-transition-controlled quantum levitation in a liquid medium.

  7. α-Sn and β-Sn precipitates in annealed epitaxial Si0.95Sn0.05

    DEFF Research Database (Denmark)

    Fyhn, M.F.; Chevallier, J.; Larsen, A.N.

    1999-01-01

    -Sn and beta-Sn crystallites. The presence of alpha-Sn at temperatures far above the bulk alpha beta transition temperature is explained by interface and pressure effects; the latter is likely to be due to the difference in thermal expansion of the precipitates and the matrix.......-temperature molecular-beam epitaxy on Si (001) and relaxed Si1-xGex substrates. Two different phases of solid Sn were identified in the annealed layers: the semiconductor phase, alpha-Sn, and the metallic phase beta-Sn The precipitates were found to consist of either only beta-Sn or to contain crystallites of both...... solid Sn phases. The orientations, the sizes and the relative number densities of the alpha-Sn and beta-Sn crystallites were investigated. in situ heating and cooling experiments were performed in the transmission electron microscope to study the melting and solidification characteristics of the alpha...

  8. Preparation of PtSnCu/C and PtSn/C electrocatalysts and activation by dealloying processes for ethanol electrooxidation

    International Nuclear Information System (INIS)

    Crisafulli, Rudy

    2013-01-01

    PtSnCu/C (with different Pt:Sn:Cu atomic ratios) and PtSn/C (50:50) electrocatalysts were prepared by borohydride (BR) and alcohol-reduction (AR) processes using H 2 PtCl 6 .6H 2 O, SnCl 2 .2H 2 O and CuCl 2 .2H 2 O as metal sources, NaBH 4 and ethylene glycol as reducing agents, 2-propanol and ethylene glycol/water as solvents and carbon black as support. In a further step, these electrocatalysts were activated by chemical (CD) and electrochemical (ED) dealloying processes through acid treatment and thin porous coating technique, respectively. These materials were characterized by energy dispersive X-ray, Xray diffraction, transmission electron microscopy, line scan energy dispersive Xray and cyclic voltammetry. Electrochemical studies for ethanol electro-oxidation were performed by cyclic voltammetry, chronoamperometry and in single Direct Ethanol Fuel Cell using Membrane Electrode Assembly (MEA). The anodic effluents were analysed by gas chromatography. The X-ray diffractograms of the as-synthesized electrocatalysts showed the typical face-centered cubic structure (FCC) of platinum and its alloys. After dealloying, the X-ray diffractograms showed that the Pt FCC structure was preserved. The crystallite sizes of the assynthesized electrocatalysts were in the range of PtSnCu/C (50:40:10) AR/ED > PtSnCu/C (50:10:40) BR/CD. PtSn/C (50:50) BR/CD, PtSnCu/C (50:10:40) BR/CD, PtSnCu/C (50:40:10) AR/CD electrocatalysts and Pt/C BASF, PtSn/C (75:25) BASF commercial electrocatalysts were tested in single Direct Ethanol Fuel Cell. The results showed the following performance for ethanol electro-oxidation: PtSn/C (50:50) BR/CD > PtSnCu/C (50:40:10) AR/CD > PtSnCu/C > PtSn/C (75:25) BASF > PtSnCu/C (50:10:40) BR/CD > Pt/C BASF. (author)

  9. Anomalous temperature behavior of Sn impurities

    International Nuclear Information System (INIS)

    Haskel, D.; Shechter, H.; Stern, E.A.; Newville, M.; Yacoby, Y.

    1993-01-01

    Sn impurities in Pb and Ag hosts have been investigated by Moessbauer effect and in Pb by x-ray-absorption fine-structure (XAFS) studies. The Sn atoms are dissolved up to at least 2 at. % in Pb and up to at least 8 at. % in Ag for the temperature ranges investigated. The concentration limit for Sn-Sn interactions is 1 at. % for Pb and 2 at. % for Ag as determined experimentally by lowering the Sn concentration until no appreciable change occurs in the Moessbauer effect. XAFS measurements verify that the Sn impurities in Pb are dissolved and predominantly at substitutional sites. For both hosts the temperature dependence of the spectral intensities of isolated Sn impurities below a temperature T 0 is as expected for vibrating about a lattice site. Above T 0 the Moessbauer spectral intensity exhibits a greatly increased rate of drop-off with temperature without appreciable broadening. This drop-off is too steep to be explained by ordinary anharmonic effects and can be explained by a liquidlike rapid hopping of the Sn, localized about a lattice site. Higher-entropy-density regions of radii somewhat more than an atomic spacing surround such impurities, and can act as nucleation sites for three-dimensional melting

  10. Effect of Sn Composition in Ge1- x Sn x Layers Grown by Using Rapid Thermal Chemical Vapor Deposition

    Science.gov (United States)

    Kil, Yeon-Ho; Kang, Sukill; Jeong, Tae Soo; Shim, Kyu-Hwan; Kim, Dae-Jung; Choi, Yong-Dae; Kim, Mi Joung; Kim, Taek Sung

    2018-05-01

    The Ge1- x Sn x layers were grown by using rapid thermal chemical-vapor deposition (RTCVD) on boron-doped p-type Si (100) substrates with Sn compositions up to x = 0.83%. In order to obtain effect of the Sn composition on the structural and the optical characteristics, we utilized highresolution X-ray diffraction (HR-XRD), etch pit density (EPD), atomic force microscopy (AFM), Raman spectroscopy, and photocurrent (PC) spectra. The Sn compositions in the Ge1- x Sn x layers were found to be of x = 0.00%, 0.51%, 0.65%, and 0.83%. The root-mean-square (RMS) of the surface roughness of the Ge1- x Sn x layer increased from 2.02 nm to 3.40 nm as the Sn composition was increased from 0.51% to 0.83%, and EPD was on the order of 108 cm-2. The Raman spectra consist of only one strong peak near 300 cm-1, which is assigned to the Ge-Ge LO peaks and the Raman peaks shift to the wave number with increasing Sn composition. Photocurrent spectra show near energy band gap peaks and their peak energies decrease with increasing Sn composition due to band-gap bowing in the Ge1- x Sn x layer. An increase in the band gap bowing parameter was observed with increasing Sn composition.

  11. Synthesis, Characterization, and Photocatalytic Activity of Zn-Doped SnO2/Zn2SnO4 Coupled Nanocomposites

    Directory of Open Access Journals (Sweden)

    Tiekun Jia

    2014-01-01

    Full Text Available Zn-doped SnO2/Zn2SnO4 nanocomposites were prepared via a two-step hydrothermal synthesis method. The as-prepared samples were characterized by X-ray diffraction (XRD, field-emission scanning electron microscopy (FESEM, transmission electron microscopy (TEM, UV-vis diffuse reflection spectroscopy, and adsorption-desorption isotherms. The results of FESEM and TEM showed that the as-prepared Zn-doped SnO2/Zn2SnO4 nanocomposites are composed of numerous nanoparticles with the size ranging from 20 nm to 50 nm. The specific surface area of the as-prepared Zn-doped SnO2/Zn2SnO4 nanocomposites is estimated to be 71.53 m2/g by the Brunauer-Emmett-Teller (BET method. The photocatalytic activity was evaluated by the degradation of methylene blue (MB, and the resulting showed that Zn-doped SnO2/Zn2SnO4 nanocomposites exhibited excellent photocatalytic activity due to their higher specific surface area and surface charge carrier transfer.

  12. The recruitment of the U5 snRNP to nascent transcripts requires internal loop 1 of U5 snRNA.

    Science.gov (United States)

    Kim, Rebecca; Paschedag, Joshua; Novikova, Natalya; Bellini, Michel

    2012-12-01

    In this study, we take advantage of the high spatial resolution offered by the nucleus and lampbrush chromosomes of the amphibian oocyte to investigate the mechanisms that regulate the intranuclear trafficking of the U5 snRNP and its recruitment to nascent transcripts. We monitor the fate of newly assembled fluorescent U5 snRNP in Xenopus oocytes depleted of U4 and/or U6 snRNAs and demonstrate that the U4/U6.U5 tri-snRNP is not required for the association of U5 snRNP with Cajal bodies, splicing speckles, and nascent transcripts. In addition, using a mutational analysis, we show that a non-functional U5 snRNP can associate with nascent transcripts, and we further characterize internal loop structure 1 of U5 snRNA as a critical element for licensing U5 snRNP to target both nascent transcripts and splicing speckles. Collectively, our data support the model where the recruitment of snRNPs onto pre-mRNAs is independent of spliceosome assembly and suggest that U5 snRNP may promote the association of the U4/U6.U5 tri-snRNP with nascent transcripts.

  13. Shape evolution in neutron-rich A ~ 140 nuclei beyond the doubly-magic nucleus 132Sn

    Science.gov (United States)

    Odahara, Atsuko; Eurica Collaboration

    2014-09-01

    Study for the shape evolution enables us to disentangle competition between spherical (single-particle like) shape and deformed (collective-like) shape as a function of neutron number. Neutron-rich nuclei in the northeast region of the doubly-magic 132Sn locates in one of the best mass region where a variety of collective modes, not only prolate deformation but also octupole collectivity, are expected to appear. These neutron-rich A ~140 nuclei were produced by using in-flight fission reaction of the 345 MeV/u 238U86+ beam at RIKEN RI Beam Factory. This experiment was performed in the framework of the EURICA (EUroball RIken Cluster Array) project based on the highly-efficient β- and isomer-decay spectroscopy methods. Around 20 extremely neutron-rich nuclei with Z=51--55 have been studied in this work. New isomers with half lives of longer than hundreds ns were found in some nuclei, such as the neutron-rich Cs isotopes. Also, preliminary results for the β decay of neutron-rich I and Xe isotopes have been obtained. Systematic change of the shape evolution for these neutron-rich isotopes will be discussed.

  14. 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

    : (1) SnPb; (2) InSn; (3) AuSn. The studies of the oxidation kinetics show that the growth of the native oxide, which covers the solder surfaces from the start of all soldering operations is self-limiting. The rate of oxidation on the molten, metallic solder surfaces is significantly reduced...... and reduction kinetics, are applied to flip-chip (FC) bonding experiments in vacuum with and without the injection of H2. Wetting in vacuum is excellent but the self-alignment during flip-chip soldering is restricted. The desired, perfectly self-aligned FC-bonds have been only achieved, using evaporated...

  15. Positional isotope exchange studies on enzyme using NMR spectroscopy

    International Nuclear Information System (INIS)

    Matsunaga, T.O.

    1987-01-01

    The isotopically enriched compounds, 18 O-β,γ-ATP and 18 O bridge-labeled pyrophosphate, synthesized previously in this laboratory, were used to investigate and measure the exchange vs. turnover of substrates and products from their central complexes in four selected enzyme systems. Using hi-field 31 P NMR, we were able to differentiate between 18 O labeled in the bridge vs. the non-bridge positions by virtue of the isotope shift upon the phosphorus nuclei. The bridge to non-bridge scrambling of the label was quantitated and the exchange vs. turnover ratios under a variety of conditions was determined. Using the substrate inhibitor carboxycreatinine, PIX experiments with 18 O-β,γ-ATP and creatine kinase were conducted. It was shown that carboxycreatinine and creatine kinase promoted exchange of the 18 O label as determined by NMR. We have concluded that carboxycreatinine is either a substrate that catalyzes very slow turnover or it catalyzes exchange by a dissociative (SN 1 /sub P/) type of mechanism

  16. Coulomb excitation of neutron-rich odd-$A$ Cd isotopes

    CERN Multimedia

    Reiter, P; Kruecken, R; Gernhaeuser, R A; Kroell, T; Leske, J; Marginean, N M

    We propose to study excited states in the odd-${A}$ isotopes $^{123,125,127}$Cd by ${\\gamma}$-ray spectroscopy following "safe" Coulomb excitation. The experiment aims to determine the B(E2) values connecting excited states with the ground state as well as the long-lived (11/2$^{-}$) isomer. The proposed study profits from the unique capability of ISOLDE to produce beams containing Cd in the ground state or in the isomeric state. Our recent results on the neutron-rich even-A Cd nuclei appear to show that these nuclei may possess some collectivity beyond that calculated by modern shell-model predictions. Beyond-mean-field calculations also predict these nuclei to be weakly deformed. These facets are surprising considering their proximity to the doubly magic $^{132}$Sn. Coulomb-excitation studies of odd-${A}$ Cd isotopes may give a unique insight into the deformation-driving roles played by different orbits in this region. Such studies of the onset of collectivity become especially important in light of recent...

  17. Zn{sub 2}SnO{sub 4}-SnO{sub 2} heterojunction nanocomposites for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Li Bihui; Luo Lijuan; Xiao Ting; Hu Xiaoyan [Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079 (China); Lu Lu; Wang, Jianbo [Department of Physics, Wuhan University, Wuhan 430072 (China); Tang Yiwen, E-mail: ywtang@phy.ccnu.edu.cn [Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079 (China)

    2011-02-03

    Graphical abstract: Display Omitted Research highlights: > The ZTO-SnO{sub 2} based DSSC shows superior photovoltaic performance than single phase ZTO or Pm-ZTO-SnO{sub 2} (physical mixture of ZTO and SnO{sub 2} nanoparticles having the same ZTO/SnO{sub 2} composition) based DSSC. > The obvious improvement in the photovoltaic performance is mainly ascribed to the efficient injected electrons transfer between the two materials via heterojunctions and consequent suppress the recombination. - Abstract: Zn{sub 2}SnO{sub 4}-SnO{sub 2} heterojunction nanocomposites (ZTO-SnO{sub 2}) with high mass amount of ZTO were synthesized by a two-step technique. The route involves firstly the synthesis of monodispersed ZnSn(OH){sub 6} nanocubes with a 50-60 nm edge length as precursors by simple coprecipitation of Na{sub 2}SnO{sub 3}.3H{sub 2}O and ZnCl{sub 2} aqueous solution, assisted by ultrasonic treatment and then followed by calcination of the precursors at 800 deg. C under N{sub 2} atmosphere. The as-synthesized nanoparticles were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Heterojunction between ZTO and SnO{sub 2} nanoparticle was confirmed by the electron energy loss spectroscopy (EELS) elemental mapping and high-resolution TEM (HRTEM). The photovoltaic performance of the ZTO-SnO{sub 2} based DSSC was examined by measuring the J-V curves both in dark and under illumination. The results show that the ZTO-SnO{sub 2} based DSSC exhibits superior photovoltaic performance as compared to the single phase ZTO based DSSCs. Under illumination of AM 1.5 simulated sunlight (100 mW/cm{sup 2}), the open circuit voltage of the cell based on ZTO-SnO{sub 2} is 706 mV, the short-current density is 2.85 mA/cm{sup 2}, and the efficiency is 1.29% which is increased by 43% from 0.90% to 1.29% compared with pure ZTO. The formation of the heterojunctions between ZTO and SnO{sub 2} nanoparticles is believed to reduce

  18. Physical properties of some Sn-based melts

    Directory of Open Access Journals (Sweden)

    Ilinykh N.

    2011-05-01

    Full Text Available The physical properties (viscosity, density, electroresistivity and magnetic susceptibility of pure tin, copper, silver, some binary (Sn - Ag, Sn - Cu, Sn - Bi, Sn - Zn and ternary (Sn-Ag-Cu, Sn-BiAg, Sn-Bi-Zn alloys with near eutectic compositions are investigated in wide temperature ranges. The irreversible decrease of viscosity in pure tin melt is discovered at 820 °С during heating. The similar anomaly with the following hysteresis of dynamic viscosity was fixed for binary and ternary alloys but at higher temperatures – 900 °С and 950 °С respectively. For all the systems it was shown that the alloys with eutectic compositions differ significantly in their electric and magnetic properties from hypo- and hypereutectic ones. Qualitative and quantitative metallographic analysis for Sn-3.8wt.%Ag-0.7wt.%Cu samples, heated low and above characteristic temperatures, showed the influence of melt overheating on crystallization kinetics.

  19. Deformation and shape transitions in hot rotating neutron deficient Te isotopes

    International Nuclear Information System (INIS)

    Aggarwal, Mamta; Mazumdar, I.

    2009-01-01

    Evolution of the nuclear shapes and deformations under the influence of temperature and rotation is investigated in Te isotopes with neutron number ranging from the proton drip line to the stability valley. Spin dependent critical temperatures for the shape transitions in Te nuclei are computed. Shape transitions from prolate at low temperature and spin to oblate via triaxiality are seen with increasing neutron number and spin.

  20. The Krásná Hora, Milešov, and Příčovy Sb-Au ore deposits, Bohemian Massif: mineralogy, fluid inclusions, and stable isotope constraints on the deposit formation

    Science.gov (United States)

    Němec, Matěj; Zachariáš, Jiří

    2018-02-01

    The Krásná Hora-Milešov and Příčovy districts (Czech Republic) are the unique examples of Sb-Au subtype orogenic gold deposits in the Bohemian Massif. They are represented by quartz-stibnite veins and massive stibnite lenses grading into low-grade, disseminated ores in altered host rocks. Gold postdates the stibnite and is often replaced by aurostibite. The ore zones are hosted by hydrothermally altered dikes of lamprophyres (Krásná Hora-Milešov) or are associated with local strike-slip faults (Příčovy). Formation of Sb-Au deposits probably occurred shortly after the main gold-bearing event (348-338 Ma; Au-only deposits) in the central part of the Bohemian Massif. Fluid inclusion analyses suggest that stibnite precipitated at 250 to 130 °C and gold at 200 to 130 °C from low-salinity aqueous fluids. The main quartz gangue hosting the ore precipitated from the same type of fluid at about 300 °C. Early quartz-arsenopyrite veins are not associated with the Sb-Au deposition and formed from low-salinity, aqueous-carbonic fluid at higher pressure and temperature ( 250 MPa, 400 °C). The estimated oxygen isotope composition of the ore-bearing fluid (4 ± 1‰ SMOW; based on post-ore calcite) suggests its metamorphic or mixed magmatic-metamorphic origin and excludes the involvement of meteoric water. Rapid cooling of warm hydrothermal fluids reacting with "cold" host rock was probably the most important factor in the formation of both stibnite and gold.

  1. Spliceosomal small nuclear RNAs of Tetrahymena thermophila and some possible snRNA-snRNA base-pairing interactions

    DEFF Research Database (Denmark)

    Orum, H; Nielsen, Henrik; Engberg, J

    1991-01-01

    We have identified and characterized the full set of spliceosomal small nuclear RNAs (snRNAs; U1, U2, U4, U5 and U6) from the ciliated protozoan Tetrahymena thermophila. With the exception of U4 snRNA, the sizes of the T. thermophila snRNAs are closely similar to their metazoan homologues. The T....... thermophila snRNAs all have unique 5' ends, which start with an adenine residue. In contrast, with the exception of U6, their 3' ends show some size heterogeneity. The primary sequences of the T. thermophila snRNAs contain the sequence motifs shown, or proposed, to be of functional importance in other...

  2. The interfacial free energy of solid Sn on the boundary interface with liquid Cd-Sn eutectic solution

    International Nuclear Information System (INIS)

    Saatci, B; Cimen, S; Pamuk, H; Guenduez, M

    2007-01-01

    Equilibrated grain boundary groove shapes for solid Sn in equilibrium with Cd-Sn liquid were directly observed after annealing a sample at the eutectic temperature for about 8 days. The thermal conductivities of the solid phase, K S , and the liquid phase, K L , for the groove shapes were measured. From the observed groove shapes, the Gibbs-Thomson coefficients were obtained with a numerical method, using the measured G, K S and K L values. The solid-liquid interfacial energy of solid Sn in equilibrium with Cd-Sn liquid was determined from the Gibbs-Thomson equation. The grain boundary energy for solid Sn was also calculated from the observed groove shapes

  3. Microstructural evolution and tensile properties of Sn-Ag-Cu mixed with Sn-Pb solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fengjiang [Department of Materials Science and Engineering and Materials Research Center, Missouri University of Science and Technology, Rolla, MO 65401 (United States); O' Keefe, Matthew [Department of Materials Science and Engineering and Materials Research Center, Missouri University of Science and Technology, Rolla, MO 65401 (United States)], E-mail: mjokeefe@mst.edu; Brinkmeyer, Brandon [Department of Materials Science and Engineering and Materials Research Center, Missouri University of Science and Technology, Rolla, MO 65401 (United States)

    2009-05-27

    The effect of incorporating eutectic Sn-Pb solder with Sn-3.0Ag-0.5Cu (SAC) Pb-free solder on the microstructure and tensile properties of the mixed alloys was investigated. Alloys containing 100, 75, 50, 25, 20, 15, 10, 5 and 0 wt% SAC, with the balance being Sn-37Pb eutectic solder alloy, were prepared and characterized. Optical and scanning electron microscopy were used to analyze the microstructures while 'mini-tensile' test specimens were fabricated and tested to determine mechanical properties at the mm length scale, more closely matching that of the solder joints. Microstructural analysis indicated that a Pb-rich phase formed and was uniformly distributed at the boundary between the Sn-rich grains or between the Sn-rich and the intermetallic compounds in the solder. Tensile results showed that mixing of the alloys resulted in an increase in both the yield and the ultimate tensile strength compared to the original solders, with the 50% SAC-50% Sn-Pb mixture having the highest measured strength. Initial investigations indicate the formation and distribution of a Pb-rich phase in the mixed solder alloys as the source of the strengthening mechanism.

  4. α-Eleostearic acid-containing triglycerides for a continuous assay to determine lipase sn-1 and sn-3 regio-preference.

    Science.gov (United States)

    El Alaoui, Meddy; Soulère, Laurent; Noiriel, Alexandre; Queneau, Yves; Abousalham, Abdelkarim

    2017-08-01

    Lipases are essentially described as sn-1 and sn-3 regio-selective. Actually few methods are available to measure this lipase regio-selectivity, moreover they require chiral chromatography analysis or specific derivations which are discontinuous and time consuming. In this study we describe a new, convenient, sensitive and continuous spectrophotometric method to screen lipases regio-selectivity using synthetic triglycerides (TG) containing α-eleostearic acid (9Z, 11E, 13E-octadecatrienoic acid) either at the sn-1 position [1-α-eleostearoyl-2,3-octadecyl-sn-glycerol (sn-EOO)] or at the sn-3 position [1,2-octadecyl-3-α-eleostearoyl-sn-glycerol (sn-OOE)] and coated onto the wells of microtiter plates. A non-hydrolysable ether bond, with a non UV-absorbing alkyl chain, was introduced at the other sn positions to prevent acyl chain migration during TG synthesis or lipolysis. The synthesis of TG containing α-eleostearic acid was performed from S-glycidol in six steps to obtain sn-EOO and in five steps to sn-OOE. The α-eleostearic acid conjugated triene constitutes an intrinsic chromophore and, consequently, confers the strong UV absorption properties of this free fatty acid as well as of the TG harboring it. The lipase activity on coated sn-EOO or sn-OOE was measured by the increase in the absorbance at 272nm due to the transition of α-eleostearic acid from the adsorbed to the soluble state. Human and porcine pancreatic lipases, guinea pig pancreatic lipase related protein 2, Thermomyces lanuginosus lipase, Candida antarctica lipase A and Candida antarctica lipase B were all used to validate the assay. This continuous high-throughput screening method could determine directly without any processes after lipolysis the regio-selectivity of various lipases. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Isospin splitting of nucleon effective mass and symmetry energy in isotopic nuclear reactions

    Science.gov (United States)

    Guo, Ya-Fei; Chen, Peng-Hui; Niu, Fei; Zhang, Hong-Fei; Jin, Gen-Ming; Feng, Zhao-Qing

    2017-10-01

    Within an isospin and momentum dependent transport model, the dynamics of isospin particles (nucleons and light clusters) in Fermi-energy heavy-ion collisions are investigated for constraining the isospin splitting of nucleon effective mass and the symmetry energy at subsaturation densities. The impacts of the isoscalar and isovector parts of the momentum dependent interaction on the emissions of isospin particles are explored, i.e., the mass splittings of and (). The single and double neutron to proton ratios of free nucleons and light particles are thoroughly investigated in the isotopic nuclear reactions of 112Sn+112Sn and 124Sn+124Sn at incident energies of 50 and 120 MeV/nucleon, respectively. It is found that both the effective mass splitting and symmetry energy impact the kinetic energy spectra of the single ratios, in particular at the high energy tail (larger than 20 MeV). The isospin splitting of nucleon effective mass slightly impacts the double ratio spectra at the energy of 50 MeV/nucleon. A soft symmetry energy with stiffness coefficient of γ s=0.5 is constrained from the experimental data with the Fermi-energy heavy-ion collisions. Supported by Major State Basic Research Development Program in China (2014CB845405, 2015CB856903), National Natural Science Foundation of China (11722546, 11675226, 11675066, U1332207) and Youth Innovation Promotion Association of Chinese Academy of Sciences

  6. Light charged clusters emitted in 32 MeV/nucleon Xe,124136+Sn,112124 reactions: Chemical equilibrium and production of 3He and 6He

    Science.gov (United States)

    Bougault, R.; Bonnet, E.; Borderie, B.; Chbihi, A.; Dell'Aquila, D.; Fable, Q.; Francalanza, L.; Frankland, J. D.; Galichet, E.; Gruyer, D.; Guinet, D.; Henri, M.; La Commara, M.; Le Neindre, N.; Lombardo, I.; Lopez, O.; Manduci, L.; Marini, P.; Pârlog, M.; Roy, R.; Saint-Onge, P.; Verde, G.; Vient, E.; Vigilante, M.; Indra Collaboration

    2018-02-01

    Background: The isovector part of the nuclear equation of state remains partly unknown and is the subject of many studies. The degree of equilibration between the two main collision partners in heavy ion reactions may be used to study the equation of state since it is connected to isospin (N /Z ) transport properties of nuclear matter. Purpose: We aim to test chemical equilibrium attainment by measuring isotopic characteristics of emitted elements as a function of impact parameter. Method: We study four Xe,124136+Sn,112124 reactions at 32 MeV/nucleon. The data were acquired with the INDRA detector at the GANIL (Caen, France) facility. Combined (projectile+target) systems are identical for two studied reactions, therefore it is possible to study the path towards chemical equilibrium from different neutron to proton ratio (N /Z ) entrance channels. The study is limited to identified isotopes detected in the forward part of the center of mass in order to focus on the evolution of projectile-like fragment isotopic content and the benefit of excellent detection performances of the forward part of the apparatus. Results: Light charged particle productions, multiplicities, and abundance ratios dependence against impact parameter are studied. It is measured to almost identical mean characteristics for the two 124Xe+124Sn and 136Xe+112Sn systems for central collisions. Comparing all four studied systems it is shown that mean values evolve from projectile N /Z to projectile+target N /Z dependence. Those identical mean characteristics concern all light charged particles except 3He whose mean behavior is strongly different. Conclusions: Our inclusive analysis (no event selection) shows that N /Z equilibration between the projectile-like and the target-like is realized to a high degree for central collisions. The light charged particle production mean value difference between 124Xe+124Sn and 136Xe+112Sn systems for central collisions is of the order of a few %. This slight

  7. Determination of Sn in 99{sup m}Tc Radiopharmaceutical Kits by Polarographic Methods; Determinacion de Estano en Radiofarmacos de 99{sup m}Tc mediante Metodos Polarograficos

    Energy Technology Data Exchange (ETDEWEB)

    Castro, M; Cruz, J; Sanchez, M

    2009-07-01

    Kits of 99{sup m}Tc radiopharmaceuticals are used in nuclear medicine for diagnosis of different diseases. Sn (II) is one of the essential components in their formulations, which is used for reduction 99{sup m}Tc-pertechnetate in cold kits for on-site preparation 99{sup m}Tc-pertechnetate radiopharmaceuticals. Usually, these cold kits contain different additives (complexing agents, antioxidants, buffers, etc.) and the amount of Sn (II) varies from kit to kit. The determination of Sn in these products is essential in assessing their quality. We report here the development of a new polarographic method for the determination of Sn (II) and total Sn in representative radiopharmaceuticals kits (for the content of Sn and chemical composition) produced at the Center of Isotopes of Cuba (CENTIS). These methods were validated by analysis of variance and recovery techniques. From the results of the validation, the characteristic functions of uncertainties and fits are considered for the established methods, which give the necessary evidences to demonstrate the usefulness of these methods according to the current trends in Analytical Chemistry. This work provides practical results of great importance for CENTIS. After the speciation of Sn in the MAG3 radiopharmaceuticals kit is inferred that the production process is affected by uncontrolled factors that influence in the product stability, which demonstrates the necessity for analytical tools for the characterization of products and processes. (Author) 57 refs.

  8. Isotope effect of impurity diffusion of cadmium in silver

    International Nuclear Information System (INIS)

    Rockosch, H.J.; Herzig, C.

    1984-01-01

    The isotope effect of impurity diffusion of cadmium in silver single crystals was measured with the radioisotopes 115 Cd/ 109 Cd by gamma spectrometry. As a mean value E = 0.37 at T = 1060 K was obtained. The correlation factor f /SUB Cd/ = 0.41 is in disagreement with previous results of other investigators due to their unfavourable experimental approach. The present value of f /SUB Cd/ , however, is consistent with those of In and Sn in Ag. A comparison with the corresponding correlation factors in the copper solvent reveals a distinct influence of lattice perturbations because of the different atomic volumes of the solvents. Since the size effect is neglected in the electrostatic diffusion model, the agreement with this model is only qualitative. The frequency ratios for vacancy jumps were calculated. The free binding enthalpy of the vacancy-impurity complex was estimated to be Δg /SUB Cd/ = -0.064 eV. This value is smaller than those for In and Sn in Ag and complies with the relative diffusivities of these impurities in Ag

  9. Effect of Pt:Sn atomic ratio on the preparation of PtSn/C electrocatalysts using electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V., E-mail: dfsilva@ipen.b, E-mail: espinace@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    PtSn/C electrocatalysts were prepared with Pt:Sn atomic ratios of 3:1, 1:1 and 1:3 in water/2-propanol using electron beam irradiation. The obtained materials were characterized by EDX, XRD and cyclic voltammetry. The ethanol electro-oxidation was studied by chronoamperometry. The XRD diffractograms of the PtSn/C electrocatalysts showed typical face-centered cubic (fcc) structure of platinum and the presence of a SnO{sub 2} phase (cassiterite). The mean crystallite sizes of Pt fcc phase was in the range of 3.0-3.5 nm. The PtSn/C electrocatalysts were active for ethanol electro-oxidation at room temperature and the material prepared with Pt:Sn atomic ratio of 1:1 showed the best activity. (author)

  10. Effect of Pt:Sn atomic ratio on the preparation of PtSn/C electrocatalysts using electron beam irradiation

    International Nuclear Information System (INIS)

    Silva, Dionisio F.; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V.

    2009-01-01

    PtSn/C electrocatalysts were prepared with Pt:Sn atomic ratios of 3:1, 1:1 and 1:3 in water/2-propanol using electron beam irradiation. The obtained materials were characterized by EDX, XRD and cyclic voltammetry. The ethanol electro-oxidation was studied by chronoamperometry. The XRD diffractograms of the PtSn/C electrocatalysts showed typical face-centered cubic (fcc) structure of platinum and the presence of a SnO 2 phase (cassiterite). The mean crystallite sizes of Pt fcc phase was in the range of 3.0-3.5 nm. The PtSn/C electrocatalysts were active for ethanol electro-oxidation at room temperature and the material prepared with Pt:Sn atomic ratio of 1:1 showed the best activity. (author)

  11. Production of Sn/SnO2/MWCNT composites by plasma oxidation after thermal evaporation from pure Sn targets onto buckypapers.

    Science.gov (United States)

    Alaf, M; Gultekin, D; Akbulut, H

    2012-12-01

    In this study, tin/tinoxide/multi oxide/multi walled carbon nano tube (Sn/SnO2/MWCNT) composites were produced by thermal evaporation and then subsequent plasma oxidation. Buckypapers having controlled porosity were prepared by vacuum filtration from functionalized MWCNTs. Pure metallic tin was thermally evaporated on the buckypapers in argon atmosphere with different thicknesses. It was determined that the evaporated pure tin nano crystals were mechanically penetrated into pores of buckypaper to form a nanocomposite. The tin/MWCNT composites were subjected to plasma oxidation process at oxygen/argon gas mixture. Three different plasma oxidation times (30, 45 and 60 minutes) were used to investigate oxidation and physical and microstructural properties. The effect of coating thickness and oxidation time was investigated to understand the effect of process parameters on the Sn and SnO2 phases after plasma oxidation. Quantitative phase analysis was performed in order to determine the relative phase amounts. The structural properties were studied by field-emission gun scanning electron microscopy (FEG-SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD).

  12. Thermal engineering of lead-free nanostructured CH3NH3SnCl3 perovskite material for thin-film solar cell

    Science.gov (United States)

    Moyez, Sk Abdul; Roy, Subhasis

    2018-01-01

    Perovskite solar cell is a kind of revolutionary investigation in the field of renewable energy which is capable of mitigates the deficiencies of silicon solar cell and its uprising efficiency can bring blessing to society. The presence of lead (Pb) in perovskite solar cell can make worst and negative impact on environment and is not desirable for our society. In this paper, general plans are anticipated by replacement of Pb with tin (Sn) in open atmosphere to fabricate the CH3NH3SnCl3 photovoltaic cells in chlorine (Cl)-rich environment. Excess uses of Cl has positive influences on morphological growth of the film and it also suppresses the oxidation tendency of tin (Sn) with existing oxygen in atmosphere and maintains same chemical atmosphere as bulk. Various characterization tools like X-ray diffraction, scanning electron microscope (SEM) have been used to study the effect of annealing temperature on crystal stricture, phase formation, impurities, and morphologies of the film. Finally, photovoltaic performance was reported using the solar simulator under 1.5 sun illumination.

  13. Properties of second phase (BaSnO3, Sn) added-YBCO thick films

    International Nuclear Information System (INIS)

    Ban, E.; Matsuoka, Y.

    1997-01-01

    The improvement of the critical current density J c of YBCO thick films has been attempted by adding BaSnO 3 powder and ultrafine Sn particles, whose diameter is about 2 μm and 7 x 10 -2 μm, respectively. It was found that the addition of a small amount of these particles was effective for the enhancement of J c of thick films prepared by a liquid-phase processing method. The 1 wt.% BaSnO 3 films fired at T s =1040-1060 C and the 3 wt.% Sn films (T s =1030-1060 C) showed J c values (77 K, 0 T) of about 2.1-2.4 x 10 3 Acm -2 and 3.1-3.5 x 10 3 Acm -2 , respectively, as compared to 2.0 x 10 3 Acm -2 for the undoped films. (orig.)

  14. Late-time spectral line formation in Type IIb supernovae, with application to SN 1993J, SN 2008ax, and SN 2011dh

    Science.gov (United States)

    Jerkstrand, A.; Ergon, M.; Smartt, S. J.; Fransson, C.; Sollerman, J.; Taubenberger, S.; Bersten, M.; Spyromilio, J.

    2015-01-01

    We investigate line formation processes in Type IIb supernovae (SNe) from 100 to 500 days post-explosion using spectral synthesis calculations. The modelling identifies the nuclear burning layers and physical mechanisms that produce the major emission lines, and the diagnostic potential of these. We compare the model calculations with data on the three best observed Type IIb SNe to-date - SN 1993J, SN 2008ax, and SN 2011dh. Oxygen nucleosynthesis depends sensitively on the main-sequence mass of the star and modelling of the [O I] λλ6300, 6364 lines constrains the progenitors of these three SNe to the MZAMS = 12-16 M⊙ range (ejected oxygen masses 0.3-0.9 M⊙), with SN 2011dh towards the lower end and SN 1993J towards the upper end of the range. The high ejecta masses from MZAMS ≳ 17 M⊙ progenitors give rise to brighter nebular phase emission lines than observed. Nucleosynthesis analysis thus supports a scenario of low-to-moderate mass progenitors for Type IIb SNe, and by implication an origin in binary systems. We demonstrate how oxygen and magnesium recombination lines may be combined to diagnose the magnesium mass in the SN ejecta. For SN 2011dh, a magnesium mass of 0.02-0.14 M⊙ is derived, which gives a Mg/O production ratio consistent with the solar value. Nitrogen left in the He envelope from CNO burning gives strong [N II] λλ6548, 6583 emission lines that dominate over Hα emission in our models. The hydrogen envelopes of Type IIb SNe are too small and dilute to produce any noticeable Hα emission or absorption after ~150 days, and nebular phase emission seen around 6550 Å is in many cases likely caused by [N II] λλ6548, 6583. Finally, the influence of radiative transport on the emergent line profiles is investigated. Significant line blocking in the metal core remains for several hundred days, which affects the emergent spectrum. These radiative transfer effects lead to early-time blueshifts of the emission line peaks, which gradually

  15. Spectroscopy of the doubly magic nucleus 100Sn and its decay

    International Nuclear Information System (INIS)

    Hinke, Christoph B.

    2010-01-01

    The nucleus 100 Sn has been the aim of a number of experimental approaches. It is of great interest for various reasons. It is presumably the heaviest particle-stable N=Z nucleus and at the same time doubly magic. Its beta decay is of particular importance because it is expected to be the purest Gamow-Teller decay in the nuclear chart and thus allows to study the question of the missing Gamow-Teller strength/the Gamow-Teller quenching due to core polarisation effects. From the beta-coincident decay spectroscopy of the daughter nucleus 100 In information about the proton-neutron interaction in this region of the nuclear chart can be obtained. Simultaneously with the implantation of the nucleus in the detector setup after production the search for delayed gamma radiation from a predicted isomeric state in 100 Sn could yield first insight into the structure of excited states in this exotic nucleus. This work presents investigation results concerning the spectroscopy of the doubly magic nucleus 100 Sn and its decay. The experiment was performed in March 2008 at the accelerator facilities of the GSI Helmholtz Zentrum Darmstadt. The neutron deficient nucleus was produced in a projectile fragmentation reaction of a 124 Xe primary beam impinging on a Beryllium target with an energy of 1 GeV x A. After a separation from other fragmentation products and a unique identification 100 Sn was stopped in an implantation detector consisting of highly segmented silicon strip detectors for decay spectroscopy. Beside the determination of the half life it was possible to detect the total energy of the emitted particle radiation in the implantation detector as well as the emitted gamma radiation with a surrounding array of Germanium detectors. With a number of approximately 70 successfully observed decays of 100 Sn a half life of T 1/2 =1.16±0.20s was obtained. The beta endpoint energy of the single channel decay yielded a value of E β 0 =3.29±0.20 MeV. The resultant Gamow

  16. Sn surface-enriched Pt-Sn bimetallic nanoparticles as a selective and stable catalyst for propane dehydrogenation

    KAUST Repository

    Zhu, Haibo; Anjum, Dalaver H.; Wang, Qingxiao; Abou-Hamad, Edy; Emsley, Lyndon; Dong, Hailin; Laveille, Paco; Li, Lidong; Samal, Akshaya Kumar; Basset, Jean-Marie

    2014-01-01

    Sn(n-C4H9) are chemically linked to the surface of Pt NPs to produce, in fine, after removal of most of the n-butyl fragment, bimetallic Pt-Sn nanoparticles. The Sn(n-CH2CH2CH2CH3) groups remaining at the surface are believed to stabilize the as

  17. Experimental evidence for Mo isotope fractionation between metal and silicate liquids

    Science.gov (United States)

    Hin, Remco C.; Burkhardt, Christoph; Schmidt, Max W.; Bourdon, Bernard; Kleine, Thorsten

    2013-10-01

    Stable isotope fractionation of siderophile elements may inform on the conditions and chemical consequences of core-mantle differentiation in planetary objects. The extent to which Mo isotopes fractionate during such metal-silicate segregation, however, is so far unexplored. We have therefore investigated equilibrium fractionation of Mo isotopes between liquid metal and liquid silicate to evaluate the potential of Mo isotopes as a new tool to study core formation. We have performed experiments at 1400 and 1600 °C in a centrifuging piston cylinder. Tin was used to lower the melting temperature of the Fe-based metal alloys to double spike technique. In experiments performed at 1400 °C, the 98Mo/95Mo ratio of silicate is 0.19±0.03‰ (95% confidence interval) heavier than that of metal. This fractionation is not significantly affected by the presence or absence of carbon. Molybdenum isotope fractionation is furthermore independent of oxygen fugacity in the range IW -1.79 to IW +0.47, which are plausible values for core formation. Experiments at 1600 °C show that, at equilibrium, the 98Mo/95Mo ratio of silicate is 0.12±0.02‰ heavier than that of metal and that the presence or absence of Sn does not affect this fractionation. Equilibrium Mo isotope fractionation between liquid metal and liquid silicate as a function of temperature can therefore be described as ΔMoMetal-Silicate98/95=-4.70(±0.59)×105/T2. Our experiments show that Mo isotope fractionation may be resolvable up to metal-silicate equilibration temperatures of about 2500 °C, rendering Mo isotopes a novel tool to investigate the conditions of core formation in objects ranging from planetesimals to Earth sized bodies.

  18. A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

    Science.gov (United States)

    Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

    2017-05-01

    The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

  19. Electronic structure and electric fields gradients of crystalline Sn(II) and Sn(IV) compounds

    International Nuclear Information System (INIS)

    Terra, J.; Guenzburger, D.

    1991-01-01

    The electronic structures of clusters representing crystalline compounds of Sn(II) and Sn(IV) were investigated, employing the first-principles Discrete Variational method and Local Density theory. Densities of states and related parameters were obtained and compared with experimental measurements and with results from band structure calculations. Effects of cluster size and of cluster truncated bonds are discussed. Electric field gradients at the Sn nucleus were calculated; results are analysed in terms of charge distribution and chemical bonding in the crystals. (author)

  20. Synthesis of Pt{sub 75}Sn{sub 25}/SnO{sub 2}/CNT nanoscaled electrode: Low onset potential of ethanol electrooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Tabet-Aoul, Amel [Institut National de la Recherche Scientifique (INRS)-Énergie, Matériaux et Télécommunications (EMT), 1650 Boulevard Lionel Boulet, Varennes, Québec, Canada J3X 1S2 (Canada); Mohamedi, Mohamed, E-mail: mohamedi@emt.inrs.ca [Institut National de la Recherche Scientifique (INRS)-Énergie, Matériaux et Télécommunications (EMT), 1650 Boulevard Lionel Boulet, Varennes, Québec, Canada J3X 1S2 (Canada)

    2013-03-15

    Highlights: ► A pulsed laser synthesis is used for the deposition of Pt, SnO{sub 2} and PtSn alloy thin films onto carbon nanotubes. ► These nanoscaled materials were characterized by FESEM, TEM, XRD and XPS. ► Enhanced electrocatalytic properties toward ethanol oxidation. -- Abstract: With the objective of lowering the potential oxidation of ethanol at PtSn nanocatalyst, we present the synthesis of free-standing catalyst layer comprising a current collector/carbon nanotubes (catalyst support)/SnO{sub 2}/Pt{sub 75}Sn{sub 25} (catalyst) nanostructured layers, each layer constructed upon the one below it. The CNTs are grown by chemical vapor deposition (CVD), whereas SnO{sub 2} and Pt{sub 75}Sn{sub 25} are synthesized by pulsed laser deposition and cross-beam laser deposition, respectively. FESEM revealed that Pt{sub 75}Sn{sub 25} nanoparticles assemble into cauliflower-like arrangement. TEM and HR-TEM showed that the Pt{sub 75}Sn{sub 25} layer thickness is of ca. 25 nm with a particle mean diameter of 4.3 nm. It was found that addition of SnO{sub 2} to Pt{sub 75}Sn{sub 25} promotes significantly the oxidation of ethanol at Pt{sub 75}Sn{sub 25} nanoparticles relative to a carbon nanotubes support. Indeed, the electrooxidation of ethanol at CNTs/SnO{sub 2}/Pt{sub 75}Sn{sub 25} electrode starts at about 100 mV negative with respect to that at CNT/Pt{sub 75}Sn{sub 25}. This decreased overpotential required to oxidize ethanol is very significant and has profound implications to developing high performing anodes for direct ethanol fuel cells technology.

  1. Massive stars dying alone: Extremely remote environments of SN2009ip and SN2010jp

    Science.gov (United States)

    Smith, Nathan

    2014-10-01

    We propose an imaging study of the astonishingly remote environments of two recent supernovae (SNe): SN2009ip and SN2010jp. Both were unusual Type IIn explosions that crashed into dense circumstellar material (CSM) ejected by the star shortly before explosion. The favored progenitors of these SNe are very massive luminous blue variable (LBV) stars. In fact, SN2009ip presents an extraordinay case where the LBV-like progenitor was actually detected directly in archival HST data, and where we obtained spectra and photometry for numerous pre-SN eruptions. No other SN has this treasure trove of detailed information about the progenitor (not even SN1987A). SN2010jp represents a possible collapsar-powered event, since it showed evidence of a fast bipolar jet in spectra and a low 56Ni mass; this would be an analog of the black-hole forming explosions that cause gamma ray bursts, but where the relativistic jet is damped by a residual H envelope on the star. In both cases, the only viable models for these SNe involve extremely massive (initial masses of 40-100 Msun) progenitor stars. This seems at odds with their extremely remote environments in the far outskirts of their host galaxies, with no detected evidence for an underlying massive star population in ground-based data (nor in the single shallow WFPC2/F606W image of SN2009ip). Here we propose deep UV HST images to search for any mid/late O-type stars nearby, deep red images to detect any red supergiants, and an H-alpha image to search for any evidence of ongoing star formation in the vicinity. These observations will place important and demanding constraints on the initial masses and ages of these progenitors.

  2. Evolution and paragenetic context of low δD hydrothermal fluids from the Panasqueira W-Sn deposit, Portugal: new evidence from microthermometric, stable isotope, noble gas and halogen analyses of primary fluid inclusions

    Science.gov (United States)

    Polya, D. A.; Foxford, K. A.; Stuart, F.; Boyce, A.; Fallick, A. E.

    2000-10-01

    The evolution, paragenetic context and origin of remarkably low δD hydrothermal fluids from the Hercynian Panasqueira W-Sn-Cu(Ag) deposit have been investigated through a combined microthermometric, stable isotope, halogen and noble gas fluid inclusion study. Large variations in δD between -60 ‰ and -134‰ have been observed in primary fluid inclusions from growth zones in a quartz crystal (Pa66) paragenetically constrained to the main sulfide stage (MSS) of ore formation. The same fluids exhibited relatively constant fluid inclusion homogenisation temperatures (254 to 260°C), salinities (7.4 to 8.7 wt.% NaCl equivalent) and calculated fluid δ 18O (3.8 to 4.4‰). All the fluids exhibited 40Ar excesses. Mean molar Br/Cl and I/Cl ratios varied from 2.3 × 10 -3-4.2 × 10 -3 and 8 × 10 -4-10 × 10 -4 respectively, with the more Br-rich fluids being associated with the more deuterium-depleted fluids. The low palaeolatitude of Panasqueira throughout the main stages of ore formation and the overwhelming predominance of meteoric fluids in the main, late and post-ore mineralising fluids with δD of -40 to -65‰ lends little support for any models involving low δD palaeometeoric water. The limited range of 40Ar∗/Cl ratios (1.1 × 10 -5-1.6 × 10 -5) also precludes boiling during the MSS or mixing of meteoric water with highly fractionated deuterium-depleted magmatic waters as viable mechanisms for producing the low δD fluids. The high Br/Cl and I/Cl of the MSS fluids indicate significant fluid interactions with organic rich sediments or metasediments, in particular regionally abundant Carboniferous coals or coaly sediments that are inferred to be depleted in deuterium by around 85‰ compared to palaeometeoric water. The large range of δD observed in the MSS fluids may be explained by isotopic exchange of palaeometeoric water with these coals at varying water/rock (wt./wt.) ratios between 0.02 and 0.002 with fluid oxygen isotopic compositions controlled by

  3. Isotopic studies of Yucca Mountain soil fluids and carbonate pedogenesis

    International Nuclear Information System (INIS)

    McConnaughey, T.A.; Whelan, J.F.; Wickland, K.P.; Moscati, R.J.

    1994-01-01

    Secondary carbonates occurring within the soils, faults, and subsurface fractures of Yucca Mountain contain some of the best available records of paleoclimate and palehydrology for the potential radioactive waste repository site. This article discusses conceptual and analytical advances being made with regard to the interpretation of stable isotope data from pedogenic carbonates, specifically related to the 13 C content of soil CO 2 , CaCO 3 , precipitation mechanisms, and isotopic fractionations between parent fluids and precipitating carbonates. The 13 C content of soil carbon dioxide from Yucca Mountain and vicinity shows most of the usual patterns expected in such contexts: Decreasing 13 C content with depth decreasing 13 C with altitude and reduced 13 C during spring. These patterns exist within the domain of a noisy data set; soil and vegetational heterogeneities, weather, and other factors apparently contribute to isotopic variability in the system. Several soil calcification mechanisms appear to be important, involving characteristic physical and chemical environments and isotopic fractionations. When CO 2 loss from thin soil solutions is an important driving factor, carbonates may contain excess heavy isotopes, compared to equilibrium precipitation with soil fluids. When root calcification serves as a proton generator for plant absorption of soil nutrients, heavy isotope deficiencies are likely. Successive cycles of dissolution and reprecipitation mix and redistribute pedogenic carbonates, and tend to isotopically homogenize and equilibrate pedogenic carbonates with soil fluids

  4. Shape coexistence in the lightest Tl isotopes studied by laser spectroscopy

    CERN Multimedia

    Herfurth, F; Antalic, S; Darby, I G; Venhart, M; Flanagan, K; Veselsky, M; Blaum, K; Radulov, D P; Beck, D; Kowalska, M; Schwarz, S; Chapman, R; Diriken, J V J; Lane, J; Rosenbusch, M

    This proposal aims at atomic spectroscopy studies of the very neutron-deficient isotopes $^{178-187}$Tl, at and far beyond the region of the neutron mid-shell at N=104, in which shape coexistence phenomena were investigated so far by particle and $\\gamma$-ray spectroscopy methods only. Our motivation for this proposal is as follows : \\\\\\\\ -These studies will provide direct data on magnetic dipole moment, spin, charge radii and deformations of these isotopes. The results will form a stringent test for our current understanding of the shape coexistence phenomena in the vicinity of the neutron mid-shell at N=104, where the relevant effects are expected to be the strongest (cf.shape staggering in the isotopes $^{181,183,185}$Hg). \\\\-The knowledge of the structure (configuration, spin, deformation) and whether one or two $\\beta$-decaying isomers are present in the parent isotopes $^{178,180,182}$Tl are crucial for understanding of the results of our recent studies of $\\beta$-delayed fission in the lightest thalli...

  5. Cytoplasmic assembly of snRNP particles from stored proteins and newly transcribed snRNA's in L929 mouse fibroblasts

    International Nuclear Information System (INIS)

    Sauterer, R.A.; Feeney, R.J.; Zieve, G.W.

    1988-01-01

    Newly synthesized snRNAs appear transiently in the cytoplasm where they assemble into ribonucleoprotein particles, the snRNP particles, before returning permanently to the interphase nucleus. In this report, bona fide cytoplasmic fractions, prepared by cell enucleation, are used for a quantitative analysis of snRNP assembly in growing mouse fibroblasts. The half-lives and abundances of the snRNP precursors in the cytoplasm and the rates of snRNP assembly are calculated in L929 cells. With the exception of U6, the major snRNAs are stable RNA species; U1 is almost totally stable while U2 has a half-life of about two cell cycles. In contrast, the majority of newly synthesized U6 decays with a half-life of about 15 h. The relative abundances of the newly synthesized snRNA species U1, U2, U3, U4 and U6 in the cytoplasm are determined by Northern hybridization using cloned probes and are approximately 2% of their nuclear abundance. The half-lives of the two major snRNA precursors in the cytoplasm (U1 and U2) are approximately 20 min as determined by labeling to steady state. The relative abundance of the snRNP B protein in the cytoplasm is determined by Western blotting with the Sm class of autoantibodies and is approximately 25% of the nuclear abundance. Kinetic studies, using the Sm antiserum to immunoprecipitate the methionine-labeled snRNP proteins, suggest that the B protein has a half-life of 90 to 120 min in the cytoplasm. These data are discussed and suggest that there is a large pool of more stable snRNP proteins in the cytoplasm available for assembly with the less abundant but more rapidly turning-over snRNAs

  6. Polymer-SnO2 composite membranes

    DEFF Research Database (Denmark)

    Nørgaard, Casper Frydendal; Skou, Eivind Morten

    . This work utilizes the latter approach and makes use of particles of tin dioxide (SnO2). Polymer-SnO2 composite membranes were successfully prepared using an ion-exchange method. SnO2 was incorporated into membranes by ion-exchange in solutions of SnCl2 ∙ 2 H2O in methanol, followed by oxidation to SnO2...... in air. The content of SnO2 proved controllable by adjusting the concentration of the ion-exchange solution. The prepared nanocomposite membranes were characterized by powder XRD, 119Sn MAS NMR, electrochemical impedance spectroscopy, water uptake and tensile stress-strain measurements. For Nafion 117...

  7. Beta-decay of {sup 103}In: evidence for the Gamow-Teller resonance near {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Karny, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Batist, L.; Brown, B.A. [and others

    1998-04-01

    The {beta} decay of the neutron-deficient isotope {sup 103}In was investigated by using total absorption {gamma}-ray spectrometry on mass-separated sources. The measurement reveals a high-lying resonance of the {beta}-decay strength in striking disagreement with high-resolution {gamma}-ray data. The result is discussed in comparison with shell-model predictions. (orig.)

  8. Improvements in the critical current densities of Nb3Sn by solid solution additions of Sn in Nb

    International Nuclear Information System (INIS)

    Luhman, T.; Suenaga, M.

    1975-01-01

    The effectiveness of solid solution additions of Sn to Nb in improving the superconducting properties of diffusion processed Nb 3 Sn conductors was examined. It was found that an increase in the superconducting critical current density, Jc, as function of layer thickness (d) may be obtained for thick Nb 3 Sn layers by solid solution additions of Sn in Nb. A large increase in J/sub c/ (d) is also achieved by increasing the Sn content in the bronze matrix material. In addition to uses of this material in magnet fabrications a potential application of these improved J/sub c/(d) values may lie in the use of Nb 3 Sn in power transmission lines. Here, a high superconducting critical current density is necessary throughout the material to carry the increased current during fault conditions. The magnetic field dependence of J/sub c/ is a function of alloy content but the alloying changes studied here do not increase the high field critical current capability of Nb 3 Sn. (auth)

  9. Production of superconducting Nb3Sn wire using Nb or Nb(Ti) and Sn(Ga) solid solution powders

    International Nuclear Information System (INIS)

    Thieme, C.L.H.; Foner, S.

    1991-01-01

    This paper reports on superconducting Nb 3 Sn wire produced by the powder metallurgy method using Nb or Nb-2.9 at% Ti powder in combination with Sn-x at% Ga powders (x = 3, 4.2, 6.2 and 9.0). Ga additions to the Sn caused considerable solid solution hardening which improved its workability. It made the Nb-Sn(Ga) powder combinations convenient for swaging and extensive wire drawing. Anneals at 950 degrees C produced wires with an overall J c of 10 4 A/cm 2 at 21.9 T for wires with both Ti in the Nb and 6.2 at% Ga in the Sn. Comparison of this wire with the best Nb(Ti)-Cu-internal Sn(Ti) shows a higher J c per A15 areas, especially in fields of 22T and above

  10. Kinetics of plasma oxidation of germanium-tin (GeSn)

    Science.gov (United States)

    Wang, Wei; Lei, Dian; Dong, Yuan; Zhang, Zheng; Pan, Jisheng; Gong, Xiao; Tok, Eng-Soon; Yeo, Yee-Chia

    2017-12-01

    The kinetics of plasma oxidation of GeSn at low temperature is investigated. The oxidation process is described by a power-law model where the oxidation rate decreases rapidly from the initial oxidation rate with increasing time. The oxidation rate of GeSn is higher than that of pure Ge, which can be explained by the higher chemical reaction rate at the GeSn-oxide/GeSn interface. In addition, the Sn atoms at the interface region exchange positions with the underlying Ge atoms during oxidation, leading to a SnO2-rich oxide near the interface. The bandgap of GeSn oxide is extracted to be 5.1 ± 0.2 eV by XPS, and the valence band offset at the GeSn-oxide/GeSn heterojunction is found to be 3.7 ± 0.2 eV. Controlled annealing experiments demonstrate that the GeSn oxide is stable with respect to annealing temperatures up to 400 °C. However, after annealing at 450 °C, the GeO2 is converted to GeO, and desorbs from the GeSn-oxide/GeSn, leaving behind Sn oxide.

  11. Fatigue and thermal fatigue of Pb-Sn solder joints

    International Nuclear Information System (INIS)

    Frear, D.; Grivas, D.; McCormack, M.; Tribula, D.; Morris, J.W. Jr.

    1987-01-01

    This paper presents a fundamental investigation of the fatigue and thermal fatigue characteristics, with an emphasis on the microstructural development during fatigue, of Sn-Pb solder joints. Fatigue tests were performed in simple shear on both 60Sn-40Pb and 5Sn-95Pb solder joints. Isothermal fatigue tests show increasing fatigue life of 60Sn-40Pb solder joints with decreasing strain and temperature. In contrast, such behavior was not observed in the isothermal fatigue of 5Sn-95Pb solder joints. Thermal fatigue results on 60Sn-40Pb solder cycled between -55 0 C and 125 0 C show that a coarsened region develops in the center of the joint. Both Pb-rich and Sn-rich phases coarsen, and cracks form within these coarsened regions. The failure mode 60Sn-40Pb solder joints in thermal and isothermal fatigue is similar: cracks form intergranularly through the Sn-rich phase or along Sn/Pb interphase boundaries. Extensive cracking is found throughout the 5Sn-95Pb joint for both thermal and isothermal fatigue. In thermal fatigue the 5Sn-95Pb solder joints failed after fewer cycles than 60Sn-40Pb

  12. DO22-(Cu,Ni)3Sn intermetallic compound nanolayer formed in Cu/Sn-nanolayer/Ni structures

    International Nuclear Information System (INIS)

    Liu Lilin; Huang, Haiyou; Fu Ran; Liu Deming; Zhang Tongyi

    2009-01-01

    The present work conducts crystal characterization by High Resolution Transmission Electron Microscopy (HRTEM) on Cu/Sn-nanolayer/Ni sandwich structures associated with the use of Energy Dispersive X-ray (EDX) analysis. The results show that DO 22 -(Cu,Ni) 3 Sn intermetallic compound (IMC) ordered structure is formed in the sandwich structures at the as-electrodeposited state. The formed DO 22 -(Cu,Ni) 3 Sn IMC is a homogeneous layer with a thickness about 10 nm. The DO 22 -(Cu,Ni) 3 Sn IMC nanolayer is stable during annealing at 250 deg. C for 810 min. The formation and stabilization of the metastable DO 22 -(Cu,Ni) 3 Sn IMC nanolayer are attributed to the less strain energy induced by lattice mismatch between the DO 22 IMC and fcc Cu crystals in comparison with that between the equilibrium DO 3 IMC and fcc Cu crystals.

  13. Liquidus Projection and Isothermal Section of the Sb-Se-Sn System

    Science.gov (United States)

    Chang, Jui-shen; Chen, Sinn-wen

    2017-12-01

    Sb-Se-Sn ternary alloys are promising chalcogenide materials. The liquidus projection and 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system are determined. Numerous Sb-Se-Sn alloys are prepared, and their primary solidification phases are examined. In addition to the three terminal phases, (Sb), (Se) and (Sn), there are Sb2Sn3, SbSn, SnSe, SnSe2, Sb2Se3, Sn2Sb9Se9, and SnSb2Se4 phases. In addition, there are two miscibility gaps along the Sb-Se and Se-Sn and sides. There are ten invariant reactions in the Sb-Se-Sn ternary system, and seven of them are experimentally determined in this study. The lowest reaction temperature of determined invariant reaction is L + SbSn = (Sn) + SnSe at 515.4 K ± 5 K (242.2 °C ± 5 °C). There are nine tie-triangles, which are Liquid + SbSn + SnSe, SbSn + SnSe + (Sb), SnSe + (Sb) + Sn2Sb9Se9, (Sb) + Sb2Se3 + Sn2Sb9Se9, SnSe + Sn2Sb9Se9 + SnSb2Se4, Sb2Se3 + Sn2Sb9Se9 + SnSb2Se4, SnSe + SnSe2 + SnSb2Se4, SnSe2 + SnSb2Se4 + Sb2Se3, and SnSe2 + Sb2Se3 + Liquid in the 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system.

  14. Isotopic anomalies in cosmic rays and winds from Wolf-Rayet stars - a new model

    International Nuclear Information System (INIS)

    Maeder, A.

    1984-01-01

    The insufficiency of the metal-rich supernovae model and of the Wolf-Rayet star model for explaining the isotopic anomalies in the galactic cosmic ray source (GCRS) is examined, and a new model for attacking the anomaly problem is proposed. The main properties of WR stars relevant to the study of GCRS are recalled, with particular emphasis on their chemical excesses and the steep galactic gradient in their distribution. The proposed model assumes that GCRs originate from two main sources of different composition and galactic distribution, probably SN's and WR stars. Their properties may change with galactocentric distance. The relevant physical physicochemical relationships are derived, and some approximations which account for the contributions of WR and SN sources in GCRS are worked out for comparison with observations. The model is found to account very well for the observed anomalies. 33 references

  15. The crystallisation of Cu2ZnSnS4 thin film solar cell absorbers from co-electroplated Cu-Zn-Sn precursors

    International Nuclear Information System (INIS)

    Schurr, R.; Hoelzing, A.; Jost, S.; Hock, R.; Voss, T.; Schulze, J.; Kirbs, A.; Ennaoui, A.; Lux-Steiner, M.; Weber, A.; Koetschau, I.; Schock, H.-W.

    2009-01-01

    The best CZTS solar cell so far was produced by co-sputtering continued with vapour phase sulfurization method. Efficiencies of up to 5.74% were reached by Katagiri et al. The one step electrochemical deposition of copper, zinc, tin and subsequent sulfurization is an alternative fabrication technique for the production of Cu 2 ZnSnS 4 based thin film solar cells. A kesterite based solar cell (size 0.5 cm 2 ) with a conversion efficiency of 3.4% (AM1.5) was produced by vapour phase sulfurization of co-electroplated Cu-Zn-Sn films. We report on results of in-situ X-ray diffraction (XRD) experiments during crystallisation of kesterite thin films from electrochemically co-deposited metal films. The kesterite crystallisation is completed by the solid state reaction of Cu 2 SnS 3 and ZnS. The measurements show two different reaction paths depending on the metal ratios in the as deposited films. In copper-rich metal films Cu 3 Sn and CuZn were found after electrodeposition. In copper-poor or near stoichiometric precursors additional Cu 6 Sn 5 and Sn phases were detected. The formation mechanism of Cu 2 SnS 3 involves the binary sulphides Cu 2-x S and SnS 2 in the absence of the binary precursor phase Cu 6 Sn 5 . The presence of Cu 6 Sn 5 leads to a preferred formation of Cu 2 SnS 3 via the reaction educts Cu 2-x S and SnS 2 in the presence of a SnS 2 (Cu 4 SnS 6 ) melt. The melt phase may be advantageous in crystallising the kesterite, leading to enhanced grain growth in the presence of a liquid phase

  16. Nuclear moments and the change of the mean square charge radius of neutron deficient thallium isotopes

    International Nuclear Information System (INIS)

    Menges, R.; Dinger, U.; Boos, N.; Huber, G.; Schroeder, S.

    1992-01-01

    The hyperfine structure, isotope and isomeric shifts in the atomic transition 6p 2 P 3/2 -7s 2 S 1/2 , λ=535 nm have been measured for the I=7 and I=2 states of 190,192,194,196 Tl, the I=1/2 and I=9/2 states of 191 Tl and the I=7 isomer of 188 Tl. The thallium isotopes were prepared as fast atomic beams at the GSI on-line mass separator following fusion reactions and - in some cases - subsequent β-decay. The nuclear dipole moments, electric quadrupole moments and the change in the nuclear mean square charge radius are evaluated. The uu-isotopes show an isomeric shift which changes sign between 192 Tl and 194 Tl. (orig.)

  17. Fe-isotope fractionation in magmatic-hydrothermal mineral deposits: A case study from the Renison Sn-W deposit, Tasmania

    Science.gov (United States)

    Wawryk, Christine M.; Foden, John D.

    2015-02-01

    We present 50 new iron isotopic analyses of source granite and mineral separates from the Renison tin deposit in western Tasmania. The aim of the study is to characterise the composition of minerals within a tin deposit associated with a reduced, S-type magma. We have analysed bulk samples of granite, and separates of pyrrhotite, pyrite, arsenopyrite, magnetite, chalcopyrite and siderite by multi-collector inductively coupled mass spectrometry. The isotopic compositions of mineral separates are consistent with theoretical predictions of equilibrium fractionation based on Mössbauer spectroscopy and other parametric calculations. Mineral-mineral pairs yield temperatures of formation that are in agreement with prior detailed fluid inclusion studies, but are spatially inconsistent with declining fluid temperatures with distance from the causative intrusion, limiting the use of Fe isotopes as a potential geothermometer, at least in this case. Comparison of our data with published data from other deposits clearly demonstrates that pyrite, magnetite and chalcopyrite from the hottest ore fluids (>300-400 °C) at Renison are isotopically heavier than minerals sampled from a deposit formed at similar temperatures, but associated with a more oxidised and less differentiated intrusion.

  18. All Small Nuclear RNAs (snRNAs) of the [U4/U6.U5] Tri-snRNP Localize to Nucleoli; Identification of the Nucleolar Localization Element of U6 snRNA

    Science.gov (United States)

    Gerbi, Susan A.; Lange, Thilo Sascha

    2002-01-01

    Previously, we showed that spliceosomal U6 small nuclear RNA (snRNA) transiently passes through the nucleolus. Herein, we report that all individual snRNAs of the [U4/U6.U5] tri-snRNP localize to nucleoli, demonstrated by fluorescence microscopy of nucleolar preparations after injection of fluorescein-labeled snRNA into Xenopus oocyte nuclei. Nucleolar localization of U6 is independent from [U4/U6] snRNP formation since sites of direct interaction of U6 snRNA with U4 snRNA are not nucleolar localization elements. Among all regions in U6, the only one required for nucleolar localization is its 3′ end, which associates with the La protein and subsequently during maturation of U6 is bound by Lsm proteins. This 3′-nucleolar localization element of U6 is both essential and sufficient for nucleolar localization and also required for localization to Cajal bodies. Conversion of the 3′ hydroxyl of U6 snRNA to a 3′ phosphate prevents association with the La protein but does not affect U6 localization to nucleoli or Cajal bodies. PMID:12221120

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-30

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

  20. Spectroscopic ellipsometry characterization of ZnO:Sn thin films with various Sn composition deposited by remote-plasma reactive sputtering

    Science.gov (United States)

    Janicek, Petr; Niang, Kham M.; Mistrik, Jan; Palka, Karel; Flewitt, Andrew J.

    2017-11-01

    ZnO:Sn thin films were deposited onto thermally oxidized silicon substrates using a remote plasma reactive sputtering. Their optical constants (refractive index n and extinction coefficient k) were determined from ellipsometric data recorded over a wide spectral range (0.05-6 eV). Parametrization of ZnO:Sn complex dielectric permittivity consists of a parameterized semiconductor oscillator function describing the short wavelength absorption edge, a Drude oscillator describing free carrier absorption in near-infrared part of spectra and a Lorentz oscillator describing the long wavelength absorption edge and intra-band absorption in the ultra-violet part of the spectra. Using a Mott-Davis model, the increase in local disorder with increasing Sn doping is quantified from the short wavelength absorption edge onset. Using the Wemple-DiDomenico single oscillator model for the transparent part of the optical constants spectra, an increase in the centroid distance of the valence and conduction bands with increasing Sn doping is shown and only slight increase in intensity of the inter-band optical transition due to Sn doping occurs. The Drude model applied in the near-infrared part of the spectra revealed the free carrier concentration and mobility of ZnO:Sn. Results show that the range of transparency of prepared ZnO:Sn layers is not dramatically affected by Sn doping whereas electrical conductivity could be controlled by Sn doping. Refractive index in the transparent part is comparable with amorphous Indium Gallium Zinc Oxide allowing utilization of prepared ZnO:Sn layers as an indium-free alternative.

  1. Crystal structure of R.E. NiSn and R.E. PdSn equiatomic compounds

    International Nuclear Information System (INIS)

    Dwight, A.E.

    1983-03-01

    Call constants and volume per formula weight are tabulated for RE NiSn (RE = La to Lu, Y) and RE PdSn (RE = Nd to Ho). The unit cell constants are also plotted versus ionic radius of the RE; trends are noted

  2. Synthesis and fundamental properties of stable Ph(3)SnSiH(3) and Ph(3)SnGeH(3) hydrides: model compounds for the design of Si-Ge-Sn photonic alloys.

    Science.gov (United States)

    Tice, Jesse B; Chizmeshya, Andrew V G; Groy, Thomas L; Kouvetakis, John

    2009-07-06

    The compounds Ph(3)SnSiH(3) and Ph(3)SnGeH(3) (Ph = C(6)H(5)) have been synthesized as colorless solids containing Sn-MH(3) (M = Si, Ge) moieties that are stable in air despite the presence of multiple and highly reactive Si-H and Ge-H bonds. These molecules are of interest since they represent potential model compounds for the design of new classes of IR semiconductors in the Si-Ge-Sn system. Their unexpected stability and high solubility also makes them a safe, convenient, and potentially useful delivery source of -SiH(3) and -GeH(3) ligands in molecular synthesis. The structure and composition of both compounds has been determined by chemical analysis and a range of spectroscopic methods including multinuclear NMR. Single crystal X-ray structures were determined and indicated that both compounds condense in a Z = 2 triclinic (P1) space group with lattice parameters (a = 9.7754(4) A, b = 9.8008(4) A, c = 10.4093(5) A, alpha = 73.35(10)(o), beta = 65.39(10)(o), gamma = 73.18(10)(o)) for Ph(3)SnSiH(3) and (a = 9.7927(2) A, b = 9.8005(2) A, c = 10.4224(2) A, alpha = 74.01(3)(o), beta = 65.48(3)(o), gamma = 73.43(3)(o)) for Ph(3)SnGeH(3). First principles density functional theory simulations are used to corroborate the molecular structures of Ph(3)SnSiH(3) and Ph(3)SnGeH(3), gain valuable insight into the relative stability of the two compounds, and provide correlations between the Si-Sn and Ge-Sn bonds in the molecules and those in tetrahedral Si-Ge-Sn solids.

  3. Nuclear structure from radioactive decay

    International Nuclear Information System (INIS)

    Wood, J.L.

    1991-01-01

    This report discusses nuclear structure from radioactive decay of the following: Neutron-Deficient Iridium Isotopes; Neutron-Deficient Platinum Isotopes; Neutron-Deficient Gold Isotopes; Neutron-Deficient Mercury Isotopes; Neutron-Deficient Thallium Isotopes; Neutron-Deficient Lead Isotopes; Neutron-Deficient Samarium Isotopes; Neutron-Deficient Promethium Isotopes; Neutron-Deficient Neodymium Isotopes; and Neutron-Deficient Praseodymium Isotopes. Also discussed are Nuclear Systematics and Models

  4. Contributions of each isotope in structural material on radiation damage in a hybrid reactor

    International Nuclear Information System (INIS)

    Günay, Mehtap

    2016-01-01

    In this study, the fluids were used in the liquid first-wall, blanket and shield zones of the designed hybrid reactor system. In this study, salt-heavy metal mixtures consisting of 93–85% Li_2_0Sn_8_0 + 5% SFG-PuO_2 and 2-10% UO_2, 93–85% Li_2_0Sn_8_0 + 5% SFG-PuO_2 and 2-10% NpO_2, and 93–85% Li_2_0Sn_8_0 + 5% SFG-PuO_2 and 2-10% UCO were used as fluids. In this study, the effect on the radiation damage of spent fuel-grade (SFG)-PuO_2, UO_2, NpO_2 and UCO contents was investigated in the structural material of a designed fusion–fission hybrid reactor system. In the designed hybrid reactor system were investigated the effect on the radiation damage of the selected fluid according to each isotopes of structural material in the structural material for 30 full power years (FPYs). Three-dimensional analyses were performed using the most recent MCNPX-2.7.0 Monte Carlo radiation transport code and the ENDF/B-VII.0 nuclear data library

  5. Identify and Quantify the Mechanistic Sources of Sensor Performance Variation Between Individual Sensors SN1 and SN2

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Aaron A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baldwin, David L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cinson, Anthony D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Anthony M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Larche, Michael R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mathews, Royce [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mullen, Crystal A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pardini, Allan F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Posakony, Gerald J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Prowant, Matthew S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hartman, Trenton S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Edwards, Matthew K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-08-06

    This Technical Letter Report satisfies the M3AR-14PN2301022 milestone, and is focused on identifying and quantifying the mechanistic sources of sensor performance variation between individual 22-element, linear phased-array sensor prototypes, SN1 and SN2. This effort constitutes an iterative evolution that supports the longer term goal of producing and demonstrating a pre-manufacturing prototype ultrasonic probe that possesses the fundamental performance characteristics necessary to enable the development of a high-temperature sodium-cooled fast reactor inspection system. The scope of the work for this portion of the PNNL effort conducted in FY14 includes performing a comparative evaluation and assessment of the performance characteristics of the SN1 and SN2 22 element PA-UT probes manufactured at PNNL. Key transducer performance parameters, such as sound field dimensions, resolution capabilities, frequency response, and bandwidth are used as a metric for the comparative evaluation and assessment of the SN1 and SN2 engineering test units.

  6. Spallation production of neutron deficient radioisotopes in North America

    International Nuclear Information System (INIS)

    Jamriska, D.J.; Peterson, E.J.; Carty, J.

    1997-01-01

    The United States Department of Energy produces a number of neutron deficient radioisotopes by high energy proton induced spallation reactions in accelerators at Los Alamos National Laboratory in New Mexico and Brookhaven National Laboratory in New York. Research isotopes are also recovered from targets irradiated at TRIUMF in British Columbia, Canada. The radioisotopes recovered are distributed for use in nuclear medicine, environmental research, physics research, and industry worldwide. In addition to the main product line of Sr-82 from either Mo or Rb targets, Cu-67 from ZnO targets, and Ge-68 from RbBr targets, these irradiation facilities also produce some unique isotopes in quantities not available from any other source such as Be-10, Al-26, Mg-28, Si-32, El-44, Fe-52, Gd-248, and Hg-194. We will describe the accelerator irradiation facilities at the Los Alamos and Brookhaven National Laboratories. The high level radiochemical processing facilities at Los Alamos and brief chemical processes from Los Alamos and Brookhaven will be described. Chemical separation techniques have been developed to recover the radioisotopes of interest in both high radiochemical purity and yield and at the same time trying to reduce or eliminate the generation of mixed waste. nearly 75 neutron deficient radioisotopes produced in spallation targets have been produced and distributed to researchers around the world since the inception of the program in 1974

  7. Controlling the Sn-C bonds content in SnO2@CNTs composite to form in situ pulverized structure for enhanced electrochemical kinetics.

    Science.gov (United States)

    Cheng, Yayi; Huang, Jianfeng; Qi, Hui; Cao, Liyun; Luo, Xiaomin; Li, Jiayin; Xu, Zhanwei; Yang, Jun

    2017-12-07

    The Sn-C bonding content between the SnO 2 and CNTs interface was controlled by the hydrothermal method and subsequent heat treatment. Electrochemical analysis found that the SnO 2 @CNTs with high Sn-C bonding content exhibited much higher capacity contribution from alloying and conversion reaction compared with the low content of Sn-C bonding even after 200 cycles. The high Sn-C bonding content enabled the SnO 2 nanoparticles to stabilize on the CNTs surface, realizing an in situ pulverization process of SnO 2 . The in situ pulverized structure was beneficial to maintain the close electrochemical contact of the working electrode during the long-term cycling and provide ultrafast transfer paths for lithium ions and electrons, which promoted the alloying and conversion reaction kinetics greatly. Therefore, the SnO 2 @CNTs composite with high Sn-C bonding content displayed highly reversible alloying and conversion reaction. It is believed that the composite could be used as a reference for design chemically bonded metal oxide/carbon composite anode materials in lithium-ion batteries.

  8. Magnesium isotopes in giants in the Milky Way inner disk and bulge: First results with 3D stellar atmospheres.

    Science.gov (United States)

    Thygesen, Anders; Sbordone, Luca; Christlieb, Norbert; Asplund, Martin

    2015-01-01

    The Milky Way bulge is one of the most poorly understood components of our galaxy and its formation history is still a matter of debate (early collapse vs. disk instability). All knowledge of its chemical evolution history has been so far derived by measuring elemental abundances: no isotopic mixtures have been measured so far in the Bulge. While quite challenging, isotopic measurements can be accomplished with present instruments in bulge stars for a few elements, Magnesium being one of them.Of the three stable Mg isotopes, the most common one, 24Mg, is mainly produced by α capture in SN II, while the other two, 25Mg and 26Mg, can be produced efficiently in massive AGB stars, through the 22Ne(α, n)25Mg(n, γ)26Mg reactions as well as the Mg-Al chain. Moreover, SN II production of 25Mg and 26Mg increases with increasing progenitor metallicity, so in older stellar populations, where only the signature of metal-poor SNe is to be expected, one should not see a significant 25Mg or 26Mg fraction. However, if larger 25Mg/24Mg and 26Mg/24Mg ratios are observed, relative to what is produced in SNe, this is a clear sign of an AGB contribution. As such, Mg isotopic ratios are a very useful probe of AGB pollution onset and chemical enrichment timescale in a stellar population.Here, we present the first ever measurements of Mg isotopes in 7 red giant stars in the Milky Way bulge and inner disk, including two stars in the bulge globular cluster NGC6522. The isotopic abundances have been derived from high resolution, high signal-to-noise VLT-UVES spectra using both standard 1D atmospheric models as well as state-of-the-art 3D hydrodynamical models and spectrosynthesis. The use of 3D atmospheric models impacts the derived ratios and this work represents the first derivation of Mg isotopes using full 3D spectrosynthesis. These results yield new constraints on the proposed formation scenarios of the Milky Way bulge.

  9. A new analysis procedure to extract fusion excitation function with large beam energy dispersions: application to the 6Li+120Sn and 7Li+119Sn

    Directory of Open Access Journals (Sweden)

    Di Pietro Alessia

    2017-01-01

    Full Text Available In the present paper it is described an analysis procedure suited for experiments where cross-sections strongly varying with energy are measured using beams having large energy dispersion. These cross-sections are typically the sub-barrier fusion excitation function of reactions induced by radioactive beams. The large beam energy dispersion, typical of these experiments, can lead to ambiguities in the association of the effective beam energy to the reaction product yields and consequently to an error in the determination of the excitation function. As a test case, the approach is applied to the experiments 6Li+120Sn and 7Li+119Sn measured in the energy range 14 MeV ≤ Ec.m. ≤28 MeV. The complete fusion cross sections are deduced from activation measurements using the stacked target technique. The results of these experiments, that employ the two weakly-bound stable Li isotopes, show that the complete fusion cross sections above the barrier are suppressed of about 70% and 85% with respect to the Universal Fusion Function, used as a standard reference, in the 6Li and 7Li induced reactions respectively. Moreover, the excitation functions of the two systems at energies below the barrier, do not show significant differences, despite the two systems have different n-transfer Qvalue.

  10. Nano-grain SnO{sub 2} electrodes for high conversion efficiency SnO{sub 2}-DSSC

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung-Hoon; Shin, Yu-Ju [Department of Chemistry, the Catholic University of Korea, Bucheon, Gyeonggi-do 422-743 (Korea, Republic of); Park, Nam-Gyu [School of Chemical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

    2011-01-15

    The nano-grain ZnO/SnO{sub 2} composite electrode was prepared by adding 5 w% of the 200-250 nm ZnO particles to the 5 nm SnO{sub 2} colloid in the presence of hydroxypropylcellulose (M.W.=80,000). The nano-grain SnO{sub 2} electrode was obtained by removing the ZnO particles from the composite electrode using acetic acid. The FE-SEM micrographs revealed that both electrodes consisted of interconnected nano-grains that were ca. 800 nm in size, and the large pores between the grains furnished the wide electrolyte diffusion channels within the electrodes. The photovoltaic properties of the nano-grain electrodes were investigated by measuring the I-V behaviors, the IPCE spectra and the ac-impedance spectra. The nano-grain electrodes exhibited remarkably improved conversion efficiencies of 3.96% for the composite and 2.98% for the SnO{sub 2} electrode compared to the value of 1.66% for the usual nano-particle SnO{sub 2} electrode. The improvement conversion efficiencies were mainly attributed to the formation of nano-grains, which facilitated the electron diffusion within the grains. The improved electrolyte diffusion as well as the light-scattering effects enhanced the photovoltaic performance of the SnO{sub 2} electrode. (author)

  11. Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

    Energy Technology Data Exchange (ETDEWEB)

    Hart, John; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James [Department of Electrical Engineering, University of Delaware, 140 Evans Hall, Newark, Delaware 19716 (United States); Adam, Thomas [College of Nanoscale Science and Engineering, SUNY, Albany, New York 12203 (United States); Kim, Yihwan; Huang, Yi-Chiau [Applied Materials, Sunnyvale, California 94085 (United States); Reznicek, Alexander [IBM Research at Albany Nanotech, Albany, New York 12203 (United States)

    2016-03-07

    Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl{sub 4} precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

  12. Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

    International Nuclear Information System (INIS)

    Hart, John; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James; Adam, Thomas; Kim, Yihwan; Huang, Yi-Chiau; Reznicek, Alexander

    2016-01-01

    Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl 4 precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

  13. Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

    Science.gov (United States)

    Hart, John; Adam, Thomas; Kim, Yihwan; Huang, Yi-Chiau; Reznicek, Alexander; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James

    2016-03-01

    Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl4 precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

  14. Electrodeposition of nanostructured Sn-Zn coatings

    Science.gov (United States)

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

    2016-03-01

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

  15. SN 2006oz

    DEFF Research Database (Denmark)

    Leloudas, Georgios; Chatzopoulos, E.; Dilday, B.

    2012-01-01

    to contribute to a better understanding of these objects by studying SN 2006oz, a newly-recognized member of this class. Methods. We present multi-color light curves of SN 2006oz from the SDSS-II SN Survey that cover its rise time, as well as an optical spectrum that shows that the explosion occurred at z ~ 0.......376. We fitted black-body functions to estimate the temperature and radius evolution of the photosphere and used the parametrized code SYNOW to model the spectrum. We constructed a bolometric light curve and compared it with explosion models. In addition, we conducted a deep search for the host galaxy...... to a recombination wave in a circumstellar medium (CSM) and discuss whether this is a common property of all similar explosions. The subsequent rise can be equally well described by input from a magnetar or by ejecta-CSM interaction, but the models are not well constrained owing to the lack of post...

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

    Science.gov (United States)

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

    2012-10-01

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

  17. Peculiarities of component interaction in {Gd, Er}-V-Sn Ternary systems at 870 K and crystal structure of RV6Sn6 stannides

    International Nuclear Information System (INIS)

    Romaka, L.; Stadnyk, Yu.; Romaka, V.V.; Demchenko, P.; Stadnyshyn, M.; Konyk, M.

    2011-01-01

    Highlights: → {Gd, Er}-V-Sn ternary systems at 870 K are characterized by formation of stannides with general compositions RV 6 Sn 6 . → Isostructural RV 6 Sn 6 compounds were also found with Y, Dy, Ho, Tm, and Lu. → The crystal structure of RV 6 Sn 6 compounds was determined by powder diffraction method. → Structural analysis showed that RV 6 Sn 6 compounds (R = Gd, Dy-Tm, Lu) are disordered; YV 6 Sn 6 is characterized by structure ordering. - Abstract: The phase equilibria in the Gd-V-Sn and Er-V-Sn ternary systems were studied at 870 K by means of X-ray and metallographic analyses in the whole concentration range. Both Gd-V-Sn and Er-V-Sn systems are characterized by formation of one ternary compound at investigated temperature, with stoichiometry RV 6 Sn 6 (SmMn 6 Sn 6 -type, space group P6/mmm, a = 0.55322(3) nm, c = 0.91949(7) nm for Gd, a = 0.55191(2) nm, c = 0.91869(8) nm for Er). Solubility of the third component in the binary compounds was not observed. Compounds with the SmMn 6 Sn 6 -type were also found with Dy, Ho, Tm, and Lu, while YV 6 Sn 6 compound crystallizes in HfFe 6 Ge 6 structure type. All investigated compounds are the first ternary stannides with rare earth elements and vanadium.

  18. Dominant effect of high anisotropy in β-Sn grain on electromigration-induced failure mechanism in Sn-3.0Ag-0.5Cu interconnect

    Energy Technology Data Exchange (ETDEWEB)

    Huang, M.L., E-mail: huang@dlut.edu.cn; Zhao, J.F.; Zhang, Z.J.; Zhao, N.

    2016-09-05

    The effect of high diffusivity anisotropy in β-Sn grain on electromigration behavior of micro-bumps was clearly demonstrated using Sn-3.0Ag-0.5Cu solder interconnects with only two β-Sn grains. The orientation of β-Sn grain (θ is defined as the angle between the c-axis of β-Sn grain and the electron flow direction) is becoming the most crucial factor to dominate the different electromigration-induced failure modes: 1) the excessive dissolution of the cathode Cu, blocking at the grain boundary and massive precipitation of columnar Cu{sub 6}Sn{sub 5} intermetallic compounds (IMCs) in the small angle θ β-Sn grain occur when electrons flow from a small angle θ β-Sn grain to a large one; 2) void formation and propagation occur at the cathode IMC/solder interface and no Cu{sub 6}Sn{sub 5} IMCs precipitate within the large angle θ β-Sn grain when electrons flow in the opposite direction. The EM-induced failure mechanism of the two β-Sn grain solder interconnects is well explained in viewpoint of atomic diffusion flux in β-Sn. - Highlights: • High anisotropy in β-Sn dominates different electromigration-induced failure mode. • Excessive dissolution of cathode Cu occurs if electrons flow in forward direction. • Voids initiate and propagate at cathode if electrons flow in reverse direction. • Failure modes are well explained in viewpoint of atomic diffusion flux in β-Sn.

  19. Ethanol electrooxidation on novel carbon supported Pt/SnOx/C catalysts with varied Pt:Sn ratio

    International Nuclear Information System (INIS)

    Jiang, L.; Colmenares, L.; Jusys, Z.; Sun, G.Q.; Behm, R.J.

    2007-01-01

    Novel carbon supported Pt/SnO x /C catalysts with Pt:Sn atomic ratios of 5:5, 6:4, 7:3 and 8:2 were prepared by a modified polyol method and characterized with respect to their structural properties (X-ray diffraction (XRD) and transmission electron microscopy (TEM)), chemical composition (XPS), their electrochemical properties (base voltammetry, CO ad stripping) and their electrocatalytic activity and selectivity for ethanol oxidation (ethanol oxidation reaction (EOR)). The data show that the Pt/SnO x /C catalysts are composed of Pt and tin oxide nanoparticles with an average Pt particle diameter of about 2 nm. The steady-state activity of the Pt/SnO x /C catalysts towards the EOR decreases with tin content at room temperature, but increases at 80 deg. C. On all Pt/SnO x /C catalysts, acetic acid and acetaldehyde represent dominant products, CO 2 formation contributes 1-3% for both potentiostatic and potentiodynamic reaction conditions. With increasing potential, the acetaldehyde yield decreases and the acetic acid yield increases. The apparent activation energies of the EOR increase with tin content (19-29 kJ mol -1 ), but are lower than on Pt/C (32 kJ mol -1 ). The somewhat better performance of the Pt/SnO x /C catalysts compared to alloyed PtSn x /C catalysts is attributed to the presence of both sufficiently large Pt ensembles for ethanol dehydrogenation and C-C bond splitting and of tin oxide for OH generation. Fuel cell measurements performed for comparison largely confirm the results obtained in model studies

  20. Syntheses, structural variants and characterization of AInM′S4 (A=alkali metals, Tl; M′ = Ge, Sn) compounds; facile ion-exchange reactions of layered NaInSnS4 and KInSnS4 compounds

    International Nuclear Information System (INIS)

    Yohannan, Jinu P.; Vidyasagar, Kanamaluru

    2016-01-01

    Ten AInM′S 4 (A=alkali metals, Tl; M′= Ge, Sn) compounds with diverse structure types have been synthesized and characterized by single crystal and powder X-ray diffraction and a variety of spectroscopic methods. They are wide band gap semiconductors. KInGeS 4 (1-β), RbInGeS 4 (2), CsInGeS 4 (3-β), TlInGeS 4 (4-β), RbInSnS 4 (8-β) and CsInSnS 4 (9) compounds with three-dimensional BaGa 2 S 4 structure and CsInGeS 4 (3-α) and TlInGeS 4 (4-α) compounds with a layered TlInSiS 4 structure have tetrahedral [InM′S 4 ] − frameworks. On the other hand, LiInSnS 4 (5) with spinel structure and NaInSnS 4 (6), KInSnS 4 (7), RbInSnS 4 (8-α) and TlInSnS 4 (10) compounds with layered structure have octahedral [InM′S 4 ] − frameworks. NaInSnS 4 (6) and KInSnS 4 (7) compounds undergo facile topotactic ion-exchange, at room temperature, with various mono-, di- and tri-valent cations in aqueous medium to give rise to metastable layered phases. - Graphical abstract: NaInSnS 4 and KInSnS 4 compounds undergo, in aqueous medium at room temperature, facile topotactic ion-exchange with mono, di and trivalent cations. Display Omitted - Highlights: • Ten AInM′S 4 compounds with diverse structure types were synthesized. • They are wide band gap semiconductors. • NaInSnS 4 and KInSnS 4 compounds undergo facile topotactic ion-exchange at room temperature.

  1. Effect of Nb on the Growth Behavior of Co3Sn2 Phase in Undercooled Co-Sn Melts

    Science.gov (United States)

    Kang, Jilong; Xu, Wanqiang; Wei, Xiuxun; Ferry, Michael; Li, Jinfu

    2016-12-01

    The growth behavior of the primary β-Co3Sn2 phase in (Co67Sn33)100- x Nb x ( x = 0, 0.5, 0.8, 1.0) hypereutectic alloys at different melt undercoolings was investigated systematically. The growth pattern of the β-Co3Sn2 phase at low undercooling changes with the Nb content from fractal seaweed ( x = 0, 0.5) into dendrite ( x = 0.8) and then returns to fractal seaweed ( x = 1.0) as a response to the changes in interface energy anisotropy and interface kinetic anisotropy. As undercooling increases, the dendritic growth of the β-Co3Sn2 phase in (Co67Sn33)99.2Nb0.8 alloy gives way to fractal seaweed growth at an undercooling of 32 K (-241 °C). At larger undercooling, the fractal seaweed growth is further replaced by compact seaweed growth, which occurred in the other three alloys investigated. The growth velocity of the β-Co3Sn2 phase slightly increases at low and intermediate undercooling but clearly decreases at larger undercooling due to the Nb addition. The growth velocity sharply increases as the growth pattern of the Co3Sn2 phase transits from fractal seaweed into compact seaweed.

  2. High field-effect mobility at the (Sr,Ba)SnO{sub 3}/BaSnO{sub 3} interface

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Kohei, E-mail: kfujiwara@imr.tohoku.ac.jp; Nishihara, Kazuki; Shiogai, Junichi; Tsukazaki, Atsushi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2016-08-15

    A perovskite oxide, BaSnO{sub 3}, has been classified as one of transparent conducting materials with high electron mobility, and its application for field-effect transistors has been the focus of recent research. Here we report transistor operation in BaSnO{sub 3}-based heterostructures with atomically smooth surfaces, fabricated on SrTiO{sub 3} substrates by the (Sr,Ba)SnO{sub 3} buffer technique. Indeed, modulation of band profiles at the channel interfaces with the insertion of wide bandgap (Sr,Ba)SnO{sub 3} as a barrier layer results in a significant improvement of field-effect mobility, implying effective carrier doping at the regulated heterointerface. These results provide an important step towards realization of high-performance BaSnO{sub 3}-based field-effect transistors.

  3. Zr-Sn-Nb alloys. Preliminary studies

    International Nuclear Information System (INIS)

    Danon, C.A.; Arias, D.E.

    1993-01-01

    Studies of the Zr-Sn-Nb diagram have been started, focussing on the Zr-rich corner, near the composition of Zirlo commercial alloy, Zr-1Sn-1Nb, and with Fe and O contents usual in nuclear grade materials. Three alloys were melted, namely Zr-4Sn-2.4Nb (A), Zr-1Sn-3Nb (B) and Zr-2.1Sn-1Nb (C). α/β transformation temperatures were measured through the variation of electrical resistivity(p) vs temperature (T). Values of 560 deg C, 670 deg C and 750 deg C were measured for the α→α+β reaction and 980 deg C, 910 deg C and 1000 deg C for the α+β→β reaction, for the A, B and C alloys, respectively in that order. Some samples were submitted to heat treatments (62 and 216 hours at 825 deg C, 120 hours at 875 deg C). Optical and scanning electronic microscopy of those samples confirmed our resistivity results. (Author)

  4. Nuclear structure from N ≅ Z to N > Z - 100Sn, 78Ni, 208Pb

    International Nuclear Information System (INIS)

    Grawe, H.; Gorska, M.; Rejmund, M.; Pfuetzner, M.; Brown, B.A.; Maier, K.H.

    1998-07-01

    The single particle (hole) energies in 100 Sn, as extrapolated by a shell model analysis of the neighbouring nuclei, show a remarkable similarity to those in 56 Ni, one major shell lower. This is borne out in nearly identical I π =2 + excitation energies, implying E(2 + )≅3 MeV in 100 Sn, and a large neutron effective E2 charge e≥1.6e. In contrast a small proton polarisation charge δe≤0.3e is found, pointing to a large isovector charge. In 104 Sn for the first time in this region strong E3 transitions with B(E3)≥17 Wu were identified, indicating E(3 - )≅3 MeV in 100 Sn. Isomer spectroscopy beyond 68 Ni following fragmentation of a 60.3 A MeV 86 Kr beam has provided first evidence on the neutron polarisation charge and the occupation of the νg 9/2 orbital beyond N=40, which is at variance with shell model calculations using realistic interactions. The N=40 subshell effect seen in E(2 + ) is not borne out in 2n separation energies. On the other hand the νg 9/2 -f 5/2 splitting of single quasiparticle energies in Ni, Fe and Cr isotopes, as deduced from M2 isomers, give no hint for deformation at Z 208 Pb a number of new isomers were observed in the fragmentation of a 1000 A MeV 238 U beam, while 3 - excitations on high spin configurations in and adjacent to 208 Pb were identified in inelastic collisions of 208 Pb+ 208 Pb. E2 and E3 strengths from stretched configurations are compared to model expectations. (orig.)

  5. Changes of electronic structure of SnTe due to high concentration of Sn vacancies

    International Nuclear Information System (INIS)

    Masek, J.; Nuzhnyj, D.N.

    1997-01-01

    Non-stoichiometric Sn 1-y Te is a strongly degenerated n-type semiconductor. This is important for understanding unusual features of magnetic behaviour of Sn 1-x Gd x Te where the relative positions of the Fermi energy and the atomic d-level of Gd govern the exchange coupling.The influence of the Sn vacancies on the band structure cannot be neglect if their concentration reaches a few atomic percent. We address this problem by using a tight-binding coherent potential approach and show that although the character of the bands remains unchanged, they are modified so that ε d can come out above the heavy-hole band. (author)

  6. Nuclear structure studies in highly neutron-deficient (114,116)Xe

    Science.gov (United States)

    Degraaf, James Hendrick

    Lifetimes of nuclear states in 114Xe and 116Xe were measured for the first time; these nuclei represent the most neutron-deficient isotopes of xenon for which lifetimes have now been measured. The fusion-evaporation reactions 58Ni(60Ni, 2p)116Xe at 223 MeV beam energy and 58Ni(58Ni, 2p)114Xe at 215 MeV beam energy were used. Lifetimes were measured using the Recoil Distance Method (RDM) with the 8π gamma-ray spectrometer at Chalk River Laboratories. The new measurements of the B(E2;2+/to 0+) strength in these nuclei, coupled with the recent measurements for heavier xenon isotopes, are well described within the framework of the O(6) symmetry limit of the Interacting Boson Approximation. The octupole nature of the negative parity side-band was also studied, and the lifetime measurements indicate a change from a K/approx 3 structure in heavier xenon isotopes to a K/approx 0,/ 1 structure in 114Xe.

  7. Interfacial reaction of Ni{sub 3}Sn{sub 4} intermetallic compound in Ni/SnAg solder/Ni system under thermomigration

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yi-Shan; Yang, Chia-Jung; Ouyang, Fan-Yi, E-mail: fyouyang@ess.nthu.edu.tw

    2016-07-25

    The growth of Ni{sub 3}Sn{sub 4} intermetallic compound (IMC) between liquid–solid interface in micro-scale Ni/SnAg/Ni system was investigated under a temperature gradient of 160 °C/cm at 260 °C on a hot plate. In contrast to a symmetrical growth of Ni{sub 3}Sn{sub 4} on both interfaces under isothermally annealed at 260 °C, the interfacial Ni{sub 3}Sn{sub 4} IMC exhibited asymmetric growth under a temperature gradient; the growth of Ni{sub 3}Sn{sub 4} at cold interface was faster than that at hot side because of temperature gradient induced mass migration of Ni atoms from the hot end toward the cold end. It was found that two-stage growth behavior of Ni{sub 3}Sn{sub 4} IMC under a temperature gradient. A growth model was established and growth kinetic analysis suggested that the chemical potential gradient controlled the growth of Ni{sub 3}Sn{sub 4} at stage I (0–120 min) whereas the dynamic equilibrium between chemical potential gradient and temperature gradient forces was attained at the hot end at stage II (120–210 min). When dynamic equilibrium was achieved at 260 °C, the critical length-temperature gradient product at the hot end was experimentally estimated to be 489.18 μm × °C/cm and the moving velocity of Ni{sub 3}Sn{sub 4} interface due to Ni consumption was calculated to be 0.134 μm/h. The molar heat of transport (Q*) of Ni atoms in molten SnAg solder was calculated to be +0.76 kJ/mol. - Highlights: • Interfacial reaction in Ni/SnAg solder/Ni system under thermal gradient. • Growth rate of Ni{sub 3}Sn{sub 4} at cold end is faster than that at hot end. • Critical length-temperature gradient product at hot end is 489.2 μm°C/cm at 260 °C. • Velocity of Ni{sub 3}Sn{sub 4} moving interface is 0.134 μm/h during dynamic equilibrium. • Molar heat of transport (Q*) of Ni in molten SnAg was +0.76 kJ/mol.

  8. The crystal structure of (Nb$_{0.75}$Cu$_{0.25}$)Sn$_{2}$ in the Cu-Nb-Sn system

    CERN Document Server

    Martin, Stefan; Nolze, Gert; Leineweber, Andreas; Leaux, Floriane; Scheuerlein, Christian

    2017-01-01

    During the processing of superconducting Nb$_{3}$Sn wire, several intermediate intermetallic phases including a previously encountered Cu-Nb-Sn phase show up. The yet unknown crystal structure of this phase is now identified by a combination of different experimental techniques and database search to be of the hexagonal NiMg2 type with a proposed composition of about (Nb0.75Cu0.25)Sn2. The structure determination started from an evaluation of the lattice parameters from EBSD Kikuchi patterns from quenched material suggesting hexagonal or orthorhombic symmetry. A database search then led to the hexagonal NiMg2 type structure, the presence of which was confirmed by a Rietveld analysis on the basis of high energy synchrotron X-ray powder diffraction data. Assuming a partial substitution of Nb in orthorhombic NbSn2 by Cu, the change of the valence electron concentration provokes a structural transformation from the CuMg2 type for NbSn2 to the NiMg2 type for (Nb0.75Cu0.25)Sn2. In the previous literature the (Nb0.7...

  9. Angular Multigrid Preconditioner for Krylov-Based Solution Techniques Applied to the Sn Equations with Highly Forward-Peaked Scattering

    Science.gov (United States)

    Turcksin, Bruno; Ragusa, Jean C.; Morel, Jim E.

    2012-01-01

    It is well known that the diffusion synthetic acceleration (DSA) methods for the Sn equations become ineffective in the Fokker-Planck forward-peaked scattering limit. In response to this deficiency, Morel and Manteuffel (1991) developed an angular multigrid method for the 1-D Sn equations. This method is very effective, costing roughly twice as much as DSA per source iteration, and yielding a maximum spectral radius of approximately 0.6 in the Fokker-Planck limit. Pautz, Adams, and Morel (PAM) (1999) later generalized the angular multigrid to 2-D, but it was found that the method was unstable with sufficiently forward-peaked mappings between the angular grids. The method was stabilized via a filtering technique based on diffusion operators, but this filtering also degraded the effectiveness of the overall scheme. The spectral radius was not bounded away from unity in the Fokker-Planck limit, although the method remained more effective than DSA. The purpose of this article is to recast the multidimensional PAM angular multigrid method without the filtering as an Sn preconditioner and use it in conjunction with the Generalized Minimal RESidual (GMRES) Krylov method. The approach ensures stability and our computational results demonstrate that it is also significantly more efficient than an analogous DSA-preconditioned Krylov method.

  10. Effect of Cooling Rate on the Longitudinal Modulus of Cu3Sn Phase of Ag-Sn-Cu Amalgam Alloy (Part II

    Directory of Open Access Journals (Sweden)

    R. H. Rusli

    2015-10-01

    Full Text Available Effects of cooling rate (at the time of solidification on the elastic constants of Cu3Sn phase of Ag-Sn-Cu dental amalgam alloy were studied. In this study, three types of alloys were made, with the composition Cu-38-37 wt% Sn by means of casting, where each alloy was subjected to different cooling rate, such as cooling on the air (AC, air blown (AB, and quenched in the water (WQ. X-ray diffraction, metallography, and Scanning Electron Microscopy with Energy Dispersive Spectroscopy studies of three alloys indicated the existence of Cu3Sn phase. Determination of the modulus of elasticity of Cu3Sn (ε phase was carried out by the measurement of longitudinal and transversal waves velocity using ultrasonic technique. The result shows that Cu3Sn (ε phase on AC gives higher modulus of elasticity values than those of Cu3Sn (ε on AB and WQ. The high modulus of elasticity value will produce a strong Ag-Sn-Cu dental amalagam alloy.

  11. Shape transition and coexistence in neutron-deficient rare earth isotopes

    CERN Multimedia

    We propose to study spectroscopic quadrupole moments of excited states and electromagnetic transition rates between them in the neutron-deficient rare earth nuclei $^{140}$Sm and $^{142}$Gd using projectile Coulomb excitation at energies of 4.7 MeV per nucleon. The rare earth nuclei below the N=82 shell closure form one of the few regions of the nuclear chart where oblate shapes are expected to occur near the ground state. Nuclear shapes are expected to change rapidly in this region, with coexistence of oblate and prolate shapes in some nuclei. The measurement of electromagnetic matrix elements represents therefore a particularly sensitive test of theoretical nuclear structure models.

  12. Controlling Cu–Sn mixing so as to enable higher critical current densities in RRP® Nb3Sn wires

    Science.gov (United States)

    Sanabria, Charlie; Field, Michael; Lee, Peter J.; Miao, Hanping; Parrell, Jeff; Larbalestier, David C.

    2018-06-01

    Dipole magnets for the proposed Future Circular Collider (FCC) demand specifications significantly beyond the limits of all existing Nb3Sn wires, in particular a critical current density (J c) of more than 1500 A mm‑2 at 16 T and 4.2 K with an effective filament diameter (D eff) of less than 20 μm. The restacked-rod-process (RRP®) is the technology closest to meeting these demands, with a J c (16 T) of up to 1400 A mm‑2, residual resistivity ratio > 100, for a sub-element size D s of 58 μm (which in RRP® wires is essentially the same as D eff). An important present limitation of RRP® is that reducing the sub-element size degrades J c to as low as 900 A mm‑2 at 16 T for D s = 35 μm. To gain an understanding of the sources of this J c degradation, we have made a detailed study of the phase evolution during the Cu–Sn ‘mixing’ stages of the wire heat treatment that occur prior to Nb3Sn formation. Using extensive microstructural quantification, we have identified the critical role that the Sn–Nb–Cu ternary phase (Nausite) can play. The Nausite forms as a well-defined ring between the Sn source and the Cu/Nb filament pack, and acts as an osmotic membrane in the 300 °C–400 °C range—greatly inhibiting Sn diffusion into the Cu/Nb filament pack while supporting a strong Cu counter-diffusion from the filament pack into the Sn core. This converts the Sn core into a mixture of the low melting point (408 °C) η phase (Cu6Sn5) and the more desirable ε phase (Cu3Sn), which decomposes at 676 °C. After the mixing stages, when heated above 408 °C towards the Nb3Sn reaction, any residual η liquefies to form additional irregular Nausite on the inside of the membrane. All Nausite decomposes into NbSn2 on further heating, and ultimately transforms into coarse-grain (and often disconnected) Nb3Sn which has little contribution to current transport. Understanding this critical Nausite reaction pathway has allowed us to simplify the mixing heat treatment to

  13. Lead-free soldering: Investigation of the Cu-Sn-Sb system along the Sn:Sb = 1:1 isopleth

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y. [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Department of Chemistry and Industrial Chemistry, University of Genoa, INSTM UdR Genoa, Via Dodecaneso 31, I-16146 Genoa (Italy); Borzone, G., E-mail: borzone@chimica.unige.it [Department of Chemistry and Industrial Chemistry, University of Genoa, INSTM UdR Genoa, Via Dodecaneso 31, I-16146 Genoa (Italy); Zanicchi, G.; Delsante, S. [Department of Chemistry and Industrial Chemistry, University of Genoa, INSTM UdR Genoa, Via Dodecaneso 31, I-16146 Genoa (Italy)

    2011-02-03

    Research highlights: > In the electronics industry, the solder alloys commonly used for assembly belong to the Sn-Pb system. Fulfilment of the EU RoHS (reduction of hazardous substances) requires the development of new lead-free alloys for applications in electronics, with the same or possibly better characteristics than the traditional Sn-Pb alloys. > This research concerns the investigation of the constitutional properties of the Cu-Sn-Sb system which is considered as lead-free replacement for high-temperature applications. - Abstract: The Cu-Sn-Sb system has been experimentally investigated by a combination of optical microscopy, differential scanning calorimetry (DSC) and electron probe microanalysis (EPMA). DSC was used to identify a total number of five invariant ternary reactions and the Sn:Sb = 1:1 isopleth section up to 65 at.% Cu was constructed by combining the DSC data with the EPMA analyses of annealed alloys and literature information. The composition limits of the binary phases were detected.

  14. Electrochemical energy storage behavior of Sn/SnO2 double phase nanocomposite anodes produced on the multiwalled carbon nanotube buckypapers for lithium-ion batteries

    Science.gov (United States)

    Alaf, Mirac; Akbulut, Hatem

    2014-02-01

    Recent development of electrode materials for Li-ion batteries is driven mainly by hybrid nanocomposite structures consisting of Li storage compounds and CNTs. In this study, tin/tinoxide (Sn/SnO2) films and tin/tinoxide/multi walled carbon nanotube (Sn/SnO2/MWCNT) nanocomposites are produced by a two steps process; thermal evaporation and subsequent plasma oxidation as anode materials for Li-ion batteries. The physical, structural, and electrochemical behaviors of the nanocomposite electrodes containing MWCNTs are discussed. The ratio between metallic tin (Sn) and tinoxide (SnO2) is controlled with plasma oxidation time and effects of the ratio are investigated on the structural and electrochemical properties. The greatly enhanced electrochemical performance is mainly due to the morphological stability and reduced diffusion resistance, which are induced by MWCNT core and deposited Sn/SnO2 double phase shell. The outstanding long-term cycling stability is a result of the two layers Sn and SnO2 phases on MWCNTs. The nanoscale Sn/SnO2/MWCNT network provides good electrical conductivity, and the creation of open spaces that buffer a large volume change during the Li-alloying/de-alloying reaction.

  15. Testing the mutually enhanced magicity effect in nuclear incompressibility via the giant monopole resonance in the {sup 204,206,208}Pb isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Patel, D. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Garg, U., E-mail: garg@nd.edu [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Adachi, T. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); Akimune, H. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Berg, G.P.A. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Harakeh, M.N. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); GANIL, CEA/DSM-CNRS/IN2P3, 14076 Cean (France); Itoh, M. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Iwamoto, C. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Long, A.; Matta, J.T. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Murakami, T. [Division of Physics and Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Okamoto, A. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Sault, K. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Talwar, R. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Uchida, M. [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8850 (Japan); and others

    2013-10-07

    Using inelastic α-scattering at extremely forward angles, including 0°, the strength distributions of the isoscalar giant monopole resonance (ISGMR) have been measured in the {sup 204,206,208}Pb isotopes in order to examine the proposed mutually enhanced magicity (MEM) effect on the nuclear incompressibility. The MEM effect had been suggested as a likely explanation of the “softness” of nuclear incompressibility observed in the ISGMR measurements in the Sn and Cd isotopes. Our experimental results rule out any manifestation of the MEM effect in nuclear incompressibility and leave the question of the softness of the open-shell nuclei unresolved still.

  16. Determination of temperature-dependent thermal conductivity of a BaSnO{sub 3−δ} single crystal by using the 3ω method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Joon; Kim, Tai Hoon; Lee, Woong-Jhae; Chai, Yisheng; Kim, Jae Wook; Jwa, Yeon Jae; Chung, Sukhwan; Kim, Seon Joong; Sohn, Egon [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Lee, Seung Min [Hanbeam Corporation Ltd, Iui-dong 906-5, Yeongtong-gu, Suwon-si, Gyeonggi-do (Korea, Republic of); Choi, Ki-Young [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, Kee Hoon, E-mail: khkim@phya.snu.ac.kr [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-06-01

    Highlights: • This is the first report about thermal conductivity of BaSnO{sub 3−δ} single crystals. • We report the successful κ measurement of the crystals by employing the 3ω method. • The BaSnO{sub 3−δ} single crystal can be a good perovskite substrate with high κ. • We found that phonons mainly contribute to the heat transport in BaSnO{sub 3−δ}. - Abstract: The single crystal of the electron doped BaSnO{sub 3−δ} system has been recently found to have high electrical mobility (up to 320 cm{sup 2} V{sup −1} s{sup −1}) at room temperature and excellent oxygen stability. Although thermal conductivity (κ) of the BaSnO{sub 3−δ} single crystal is an important physical quantity, the κ measurement by the conventional DC method has been difficult due to the limited crystal size. Herein, we report the first measurement of κ by using the 3ω method from ∼20 to 300 K in the oxygen deficient BaSnO{sub 3−δ} single crystal with carrier concentration of ∼10{sup 18} cm{sup −3}. We found that κ is proportional to T{sup −1} above 50 K, indicating that phonons mainly contribute to the heat transport. Moreover, the electronic contribution is determined as ∼4% of the measured κ from the Wiedemann–Franz law. The κ value is 0.132 W cm{sup −1} K{sup −1} at room temperature and is increased progressively at lower temperatures, becoming overall larger than that of the SrTiO{sub 3} single crystal. Our results thus point out that BaSnO{sub 3−δ} can be a good substrate for growing transparent electronic thin films with the perovskite structure.

  17. CO oxidation on PtSn nanoparticle catalysts occurs at the interface of Pt and Sn oxide domains formed under reaction conditions

    KAUST Repository

    Michalak, William D.

    2014-04-01

    The barrier to CO oxidation on Pt catalysts is the strongly bound adsorbed CO, which inhibits O2 adsorption and hinders CO2 formation. Using reaction studies and in situ X-ray spectroscopy with colloidally prepared, monodisperse ∼2 nm Pt and PtSn nanoparticle catalysts, we show that the addition of Sn to Pt provides distinctly different reaction sites and a more efficient reaction mechanism for CO oxidation compared to pure Pt catalysts. To probe the influence of Sn, we intentionally poisoned the Pt component of the nanoparticle catalysts using a CO-rich atmosphere. With a reaction environment comprised of 100 Torr CO and 40 Torr O2 and a temperature range between 200 and 300 C, Pt and PtSn catalysts exhibited activation barriers for CO2 formation of 133 kJ/mol and 35 kJ/mol, respectively. While pure Sn is readily oxidized and is not active for CO oxidation, the addition of Sn to Pt provides an active site for O2 adsorption that is important when Pt is covered with CO. Sn oxide was identified as the active Sn species under reaction conditions by in situ ambient pressure X-ray photoelectron spectroscopy measurements. While chemical signatures of Pt and Sn indicated intermixed metallic components under reducing conditions, Pt and Sn were found to reversibly separate into isolated domains of Pt and oxidic Sn on the nanoparticle surface under reaction conditions of 100 mTorr CO and 40 mTorr O2 between temperatures of 200-275 C. Under these conditions, PtSn catalysts exhibited apparent reaction orders in O2 for CO 2 production that were 0.5 and lower with increasing partial pressures. These reaction orders contrast the first-order dependence in O 2 known for pure Pt. The differences in activation barriers, non-first-order dependence in O2, and the presence of a partially oxidized Sn indicate that the enhanced activity is due to a reaction mechanism that occurs at a Pt/Sn oxide interface present at the nanoparticle surface. © 2014 Published by Elsevier Inc.

  18. Development of a 117mSn preparation method

    International Nuclear Information System (INIS)

    Moraes, Vanessa; Osso Junior, Joao Alberto

    2000-01-01

    117m Sn is a radioisotope with suitable characteristics to be used in nuclear medicine as radiotherapy, when labeled with DTPA. The aim of this work is the preparation of 117m Sn from irradiation of the natural tin with proton beam at the cyclotron CV-28 of IPEN-CNEN/SP via the nuclear reaction nat Sn (p, xn) 117 Sb to 117m Sn. Due to the formation of the Sb precursor it is necessary to perform a chemical separation for Sb-Sn. The separation method used was the ion exchange, due to its utilization facilities for radioactive material. Chemical, radiochemical and radionuclidic methods were also developed for the quality control of the final product, the 117m Sn. (author)

  19. Exploration work function and optical properties of monolayer SnSe allotropes

    Science.gov (United States)

    Cui, Zhen; Wang, Xia; Ding, Yingchun; Li, Meiqin

    2018-02-01

    The work function and optical properties are investigated with density functional theory for three monolayer SnSe allotropes. The calculated results indicate that the α-SnSe, δ-SnSe, ε-SnSe are semiconductor with the band gaps of 0.90, 1.25, and 1.50 eV, respectively. Meanwhile, the work function of δ-SnSe is lower than α-SnSe and ε-SnSe, which indicates that the δ-SnSe can be prepared of photoemission and field emission nanodevices. More importantly, the α-SnSe, δ-SnSe, ε-SnSe with the large static dielectric constants are 4.22, 5.48, and 3.61, which demonstrate that the three monolayer SnSe allotropes can be fabricated the capacitor. In addition, the static refractive index of δ-SnSe is larger than α-SnSe and ε-SnSe. The different optical properties with three monolayer SnSe allotropes reveal that the allotropes can regulate the properties of the materials. Moreover, our researched results show that the three monolayer SnSe allotropes are sufficient for fabrication of optoelectronic nanodevices.

  20. High-precision gamma-ray spectroscopy for enhancing production and application of medical isotopes

    Science.gov (United States)

    McCutchan, E. A.; Sonzogni, A. A.; Smith, S. V.; Muench, L.; Nino, M.; Greene, J. P.; Carpenter, M. P.; Zhu, S.; Chillery, T.; Chowdhury, P.; Harding, R.; Lister, C. J.

    2015-10-01

    Nuclear medicine is a field which requires precise decay data for use in planning radionuclide production and in imaging and therapeutic applications. To address deficiencies in decay data, sources of medical isotopes were produced and purified at the Brookhaven Linear Isotope Producer (BLIP) then shipped to Argonne National Laboratory where high-precision, gamma-ray measurements were performed using Gammasphere. New decay schemes for a number of PET isotopes and the impact on dose calculations will be presented. To investigate the production of next-generation theranostic or radiotherapeutic isotopes, cross section measurements with high energy protons have also been explored at BLIP. The 100-200 MeV proton energy regime is relatively unexplored for isotope production, thus offering high discovery potential but at the same time a challenging analysis due to the large number of open channels at these energies. Results of cross sections deduced from Compton-suppressed, coincidence gamma-ray spectroscopy performed at Lowell will be presented, focusing on the production of platinum isotopes by irradiating natural platinum foils with 100 to 200 MeV protons. DOE Isotope Program is acknowledged for funding ST5001030. Work supported by the US DOE under Grant DE-FG02-94ER40848 and Contracts DE-AC02-98CH10946 and DE-AC02-06CH11357.

  1. Local atomic structure inheritance in Ag50Sn50 melt

    International Nuclear Information System (INIS)

    Bai, Yanwen; Bian, Xiufang; Qin, Jingyu; Hu, Lina; Yang, Jianfei; Zhang, Kai; Zhao, Xiaolin; Yang, Chuncheng; Zhang, Shuo; Huang, Yuying

    2014-01-01

    Local structure inheritance signatures were observed during the alloying process of the Ag 50 Sn 50 melt, using high-temperature X-ray diffraction and ab initio molecular dynamics simulations. The coordination number N m around Ag atom is similar in the alloy and in pure Ag melts (N m  ∼ 10), while, during the alloying process, the local structure around Sn atoms rearranges. Sn-Sn covalent bonds were substituted by Ag-Sn chemical bonds, and the total coordination number around Sn increases by about 70% as compared with those in the pure Sn melt. Changes in the electronic structure of the alloy have been studied by Ag and Sn K-edge X-ray absorption spectroscopy, as well as by calculations of the partial density of states. We propose that a leading mechanism for local structure inheritance in Ag 50 Sn 50 is due to s-p dehybridization of Sn and to the interplay between Sn-s and Ag-d electrons

  2. Annealing of RF-magnetron sputtered SnS{sub 2} precursors as a new route for single phase SnS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, M.G., E-mail: martasousa@ua.pt [AIN, I3N and Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Cunha, A.F. da, E-mail: antonio.cunha@ua.pt [AIN, I3N and Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Fernandes, P.A., E-mail: pafernandes@ua.pt [AIN, I3N and Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Departamento de Física, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida 431, 4200-072 Porto (Portugal)

    2014-04-01

    Tin sulphide thin films have been grown on soda-lime glass substrates through the annealing of RF-magnetron sputtered SnS{sub 2} precursors. Three different approaches to the annealing were compared and the resulting films thoroughly studied. One series of precursors was annealed in a tubular furnace directly exposed to a flux of sulphur vapour plus forming gas, N{sub 2} + 5%H{sub 2}, and at a constant pressure of 500 mbar. The other two series of identical precursors were annealed in the same furnace but inside a graphite box with and without elemental sulphur evaporation again in the presence of N{sub 2} + 5%H{sub 2} and at the same pressure as for the sulphur flux experiments. Different maximum annealing temperatures for each set of samples, in the range of 300–570 °C, were tested to study their effects on the properties of the final films. The resulting phases were structurally investigated by X-Ray Diffraction (XRD) and Raman spectroscopy. Annealing of SnS{sub 2} precursors in sulphur flux produced films where SnS{sub 2} was dominant for temperatures up to 480 °C. Increasing the temperature to 530 °C and 570 °C led to films where the dominant phase became Sn{sub 2}S{sub 3}. Annealing of SnS{sub 2} precursors in a graphite box with sulphur vapour at temperatures in the range between 300 °C and 480 °C the films are multi-phase, containing Sn{sub 2}S{sub 3}, SnS{sub 2} and SnS. For high annealing temperatures of 530 °C and 570 °C the films have SnS as the dominant phase. Annealing of SnS{sub 2} precursors in a graphite box without sulphur vapour at 300 °C and 360 °C the films are essentially amorphous, at 420 °C SnS{sub 2} is the dominant phase. For temperatures of 480 °C and 530 °C SnS is the dominant phase but also same residual SnS{sub 2} and Sn{sub 2}S{sub 3} phases are observed. For annealing at 570 °C, according to the XRD results the films appear to be single phase SnS. The composition was studied using energy dispersive spectroscopy being

  3. Excitation of giant monopole resonance in {sup 208}Pb and {sup 116}Sn using inelastic deuteron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Patel, D.; Garg, U. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Itoh, M. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Akimune, H. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Berg, G.P.A. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Harakeh, M.N. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); GANIL, CEA/DSM-CNRS/IN2P3, 14076 Caen (France); Iwamoto, C. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Kawabata, T. [Division of Physics and Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Kawase, K. [Japan Atomic Energy Agency, Kyoto 619-0215 (Japan); Matta, J.T. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Murakami, T. [Division of Physics and Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Okamoto, A. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Sako, T. [Japan Atomic Energy Agency, Kyoto 619-0215 (Japan); Schlax, K.W. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Takahashi, F. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); White, M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Yosoi, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan)

    2014-07-30

    The excitation of the isoscalar giant monopole resonance (ISGMR) in {sup 208}Pb and {sup 116}Sn has been investigated using small-angle (including 0°) inelastic scattering of 100 MeV/u deuteron and multipole-decomposition analysis (MDA). The extracted strength distributions agree well with those from inelastic scattering of 100 MeV/u α particles. These measurements establish deuteron inelastic scattering at E{sub d}∼100 MeV/u as a suitable probe for extraction of the ISGMR strength with MDA, making feasible the investigation of this resonance in radioactive isotopes in inverse kinematics.

  4. Enhanced hydrogen storage capacity of Ni/Sn-coated MWCNT nanocomposites

    Science.gov (United States)

    Varshoy, Shokufeh; Khoshnevisan, Bahram; Behpour, Mohsen

    2018-02-01

    The hydrogen storage capacity of Ni-Sn, Ni-Sn/multi-walled carbon nanotube (MWCNT) and Ni/Sn-coated MWCNT electrodes was investigated by using a chronopotentiometry method. The Sn layer was electrochemically deposited inside pores of nanoscale Ni foam. The MWCNTs were put on the Ni-Sn foam with nanoscale porosities using an electrophoretic deposition method and coated with Sn nanoparticles by an electroplating process. X-ray diffraction and energy dispersive spectroscopy results indicated that the Sn layer and MWCNTs are successfully deposited on the surface of Ni substrate. On the other hand, a field-emission scanning electron microscopy technique revealed the morphology of resulting Ni foam, Ni-Sn and Ni-Sn/MWCNT electrodes. In order to measure the hydrogen adsorption performed in a three electrode cell, the Ni-Sn, Ni-Sn/MWCNT and Ni/Sn-coated MWCNT electrodes were used as working electrodes whereas Pt and Ag/AgCl electrodes were employed as counter and reference electrodes, respectively. Our results on the discharge capacity in different electrodes represent that the Ni/Sn-coated MWCNT has a maximum discharge capacity of ˜30 000 mAh g-1 for 20 cycles compared to that of Ni-Sn/MWCNT electrodes for 15 cycles (˜9500 mAh g-1). By increasing the number of cycles in a constant current, the corresponding capacity increases, thereby reaching a constant amount for 20 cycles.

  5. The crystallisation of Cu{sub 2}ZnSnS{sub 4} thin film solar cell absorbers from co-electroplated Cu-Zn-Sn precursors

    Energy Technology Data Exchange (ETDEWEB)

    Schurr, R. [Chair for Crystallography and Structural Physics, University of Erlangen-Nuernberg, Staudtstrasse 3, D-91058 Erlangen (Germany)], E-mail: schurr@krist.uni-erlangen.de; Hoelzing, A.; Jost, S.; Hock, R. [Chair for Crystallography and Structural Physics, University of Erlangen-Nuernberg, Staudtstrasse 3, D-91058 Erlangen (Germany); Voss, T.; Schulze, J.; Kirbs, A. [Atotech Deutschland GmbH, Erasmusstrasse 20, D-10553 Berlin (Germany); Ennaoui, A.; Lux-Steiner, M. [Heterogeneous Material Systems SE II, Hahn-Meitner-Institut, Glienickerstr.100, D-14109 Berlin (Germany); Weber, A.; Koetschau, I.; Schock, H.-W. [Technology SE III, Hahn-Meitner-Institut, Glienickerstr.100, D-14109 Berlin (Germany)

    2009-02-02

    The best CZTS solar cell so far was produced by co-sputtering continued with vapour phase sulfurization method. Efficiencies of up to 5.74% were reached by Katagiri et al. The one step electrochemical deposition of copper, zinc, tin and subsequent sulfurization is an alternative fabrication technique for the production of Cu{sub 2}ZnSnS{sub 4} based thin film solar cells. A kesterite based solar cell (size 0.5 cm{sup 2}) with a conversion efficiency of 3.4% (AM1.5) was produced by vapour phase sulfurization of co-electroplated Cu-Zn-Sn films. We report on results of in-situ X-ray diffraction (XRD) experiments during crystallisation of kesterite thin films from electrochemically co-deposited metal films. The kesterite crystallisation is completed by the solid state reaction of Cu{sub 2}SnS{sub 3} and ZnS. The measurements show two different reaction paths depending on the metal ratios in the as deposited films. In copper-rich metal films Cu{sub 3}Sn and CuZn were found after electrodeposition. In copper-poor or near stoichiometric precursors additional Cu{sub 6}Sn{sub 5} and Sn phases were detected. The formation mechanism of Cu{sub 2}SnS{sub 3} involves the binary sulphides Cu{sub 2-x}S and SnS{sub 2} in the absence of the binary precursor phase Cu{sub 6}Sn{sub 5}. The presence of Cu{sub 6}Sn{sub 5} leads to a preferred formation of Cu{sub 2}SnS{sub 3} via the reaction educts Cu{sub 2-x}S and SnS{sub 2} in the presence of a SnS{sub 2}(Cu{sub 4}SnS{sub 6}) melt. The melt phase may be advantageous in crystallising the kesterite, leading to enhanced grain growth in the presence of a liquid phase.

  6. Diffusion couple studies of the Ni-Bi-Sn system

    Directory of Open Access Journals (Sweden)

    Vassilev G.

    2012-01-01

    Full Text Available Investigations of Ni-Bi-Sn system were performed in order to inquire the phase diagram and to assess some diffusion kinetic parameters. For this purpose diffusion couples consisting of solid nickel (preliminary electroplated with tin and liquid Bi-Sn phase were annealed at 370 °C. Three compositions (0.8, 0.6 and 0.4 mole fractions Sn of the Bi-Sn melts were chosen. Annealing times from 24 to 216 h were applied. The phase and chemical compositions of the contact zone were determined by means of electron scanning microscope. It was confirmed that the diffusion layers consist mainly of Ni3Sn4 but other intermetallic phases grow as well. For the first time metastable Ni-Sn phases as NiSn and NiSn8 (NiSn9 were observed in metallurgical alloys (i.e. not in electroplated samples. The existence of a ternary compound previously reported in the literature was confirmed. More than one ternary Ni-Bi-Sn compounds might possibly be admitted. A growth coefficient of (2.29 ± 0.02 x 10-15 m2 s-1 was obtained. It was found that the apparent activation energy for diffusion layers growth (18 ± 8 kJ mol-1 is inferior to that one assessed at growth from solid state Bi-Sn mixtures (88 ± 12 kJ mol-1.

  7. Theoretical calculation of performance enhancement in lattice-matched SiGeSn/GeSn p-channel tunneling field-effect transistor with type-II staggered tunneling junction

    Science.gov (United States)

    Wang, Hongjuan; Han, Genquan; Wang, Yibo; Peng, Yue; Liu, Yan; Zhang, Chunfu; Zhang, Jincheng; Hu, Shengdong; Hao, Yue

    2016-04-01

    In this work, a lattice-matched SiGeSn/GeSn heterostructure p-channel tunneling field-effect transistor (hetero-PTFET) with a type-II staggered tunneling junction (TJ) is investigated theoretically. Lattice matching and type-II band alignment at the Γ-point is obtained at the SiGeSn/GeSn interface by tuning Sn and Si compositions. A steeper subthreshold swing (SS) and a higher on state current (I ON) are demonstrated in SiGeSn/GeSn hetero-PTFET than in GeSn homo-PTFET. Si0.31Ge0.49Sn0.20/Ge0.88Sn0.12 hetero-PTFET achieves a 2.3-fold higher I ON than Ge0.88Sn0.12 homo-PTFET at V DD of 0.3 V. Hetero-PTFET achieves a more abrupt hole profile and a higher carrier density near TJ than the homo-PTFET, which contributes to the significantly enhanced band-to-band tunneling (BTBT) rate and tunneling current in hetero-PTFET.

  8. Numerical analysis of In_xGa_1_−_xN/SnS and Al_xGa_1_−_xN/SnS heterojunction solar cells

    International Nuclear Information System (INIS)

    Lin, Shuo; Li, Xirong; Pan, Huaqing; Chen, Huanting; Li, Xiuyan; Li, Yan; Zhou, Jinrong

    2016-01-01

    Highlights: • In_xGa_1_−_xN/SnS and Al_xGa_1_−_xN/SnS solar cells are studied by numerical analysis. • Performances of In_xGa_1_−_xN/SnS solar cells enhanced with decreasing In content. • The electron barrier leads to the degraded efficiency of Al_xGa_1_−_xN/SnS solar cells. • GaN/SnS solar cell exhibits the highest efficiency 26.34%. - Abstract: In this work the photovoltaic properties of In_xGa_1_−_xN/SnS and Al_xGa_1_−_xN/SnS heterojunction solar cells are studied by numerical analysis. The photovoltaic performances of In_xGa_1_−_xN/SnS solar cells are enhanced with the decreasing In content and the GaN/SnS solar cell exhibits the highest efficiency. The efficiencies of GaN/SnS solar cell improve with the increased SnS thickness and the reduced GaN thickness. For the Al_xGa_1_−_xN/SnS solar cells, there is electron barrier in the Al_xGa_1_−_xN/SnS interface. The electron barrier becomes larger with increasing Al content and lead to the degraded efficiency of Al_xGa_1_−_xN/SnS solar cells. The simulation contributes to designing and fabricating SnS solar cells.

  9. Noncollinear antiferromagnetic Mn3Sn films

    Science.gov (United States)

    Markou, A.; Taylor, J. M.; Kalache, A.; Werner, P.; Parkin, S. S. P.; Felser, C.

    2018-05-01

    Noncollinear hexagonal antiferromagnets with almost zero net magnetization were recently shown to demonstrate giant anomalous Hall effect. Here, we present the structural and magnetic properties of noncollinear antiferromagnetic Mn3Sn thin films heteroepitaxially grown on Y:ZrO2 (111) substrates with a Ru underlayer. The Mn3Sn films were crystallized in the hexagonal D 019 structure with c -axis preferred (0001) crystal orientation. The Mn3Sn films are discontinuous, forming large islands of approximately 400 nm in width, but are chemical homogeneous and characterized by near perfect heteroepitaxy. Furthermore, the thin films show weak ferromagnetism with an in-plane uncompensated magnetization of M =34 kA/m and coercivity of μ0Hc=4.0 mT at room temperature. Additionally, the exchange bias effect was studied in Mn3Sn /Py bilayers. Exchange bias fields up to μ0HEB=12.6 mT can be achieved at 5 K. These results show Mn3Sn films to be an attractive material for applications in antiferromagnetic spintronics.

  10. 51Cr diffusion in Zr-Sn alloys

    International Nuclear Information System (INIS)

    Nicolai, L.I.; Migoni, R.L.; Hojvat de Tendler, Ruth

    1982-01-01

    The 51 Cr volume diffusion in Zr-Sn alloys is measured in polycrystals with big grains by the thin-film method. The Sn content in the alloys ranges from 0.39% at to 6.66 % at. In the beta-phase the analysed temperature range is 982 deg C-1240 deg C. The Sn dehances the 51 Cr diffusion in beta-Zr, the effect being small but well defined. Assuming the formation of Sn-Cr dimers, the linear dehancement coefficient b and the parameters for the variation of b with temperature were calculated. The parameters Q and D o were calculated for the more diluted alloys and, upon application of the Zener theory for D o , a negative contribution to the activation entropy is found. Three experiments at different temperatures were performed in the alpha-phase. 51 Cr diffuses very fast in alpha-Zr-Sn. No definite correlation is found between the 51 Cr diffusivity and the increasing Sn concentration, probably due to the anisotropy of the alfa-phase. (M.E.L.) [es

  11. Impact Parameter Dependence of the Double Neutron/Proton Ratio of Nucleon Emissions in Isotopic Reaction Systems

    International Nuclear Information System (INIS)

    Xun-Chao, Zhang; Gao-Chan, Yong; Bao-An, Li; Lie-Wen, Chen

    2009-01-01

    Within the transport model IBUU04, we investigate the double neutron/proton ratio of free nucleons taken from two reaction systems using two Sn isotopes at a beam energy of 50 MeV/nucleon and with impact parameters 2 fm, 4 fm and 8 fm, respectively. It is found that the double neutron/proton ratio from peripheral collisions is more sensitive to the density dependence of the symmetry energy than those from mid-central and central collisions. (nuclear physics)

  12. Thermodynamic assessment of the Sn-Co lead-free solder system

    Science.gov (United States)

    Liu, Libin; Andersson, Cristina; Liu, Johan

    2004-09-01

    The Sn-Co-Cu eutectic alloy can be a less expensive alternative for the Sn-Ag-Cu alloy. In order to find the eutectic solder composition of the Sn-Co-Cu system, the Sn-Co binary system has been thoroughly assessed with the calculation of phase diagram (CALPHAD) method. The liquid phase, the FCC and HCP Co-rich solid solution, and the BCT Sn-rich solid solution have been described by the Redlich-Kister model. The Hillert-Jarl-Inden model has been used to describe the magnetic contributions to Gibbs energy in FCC and HCP. The CoSn2, CoSn, Co3Sn2_β, and Co3Sn2_α phases have been treated as stoichiometric phases. A series of thermodynamic parameters have been obtained. The calculated phase diagram and thermodynamic properties are in good agreement with the experimental data. The obtained thermodynamic data was used to extrapolate the ternary Sn-Co-Cu phase diagram. The composition of the Sn-rich eutectic point of the Sn-Co-Cu system was found to be 224°C, 0.4% Co, and 0.7% Cu.

  13. Phase analysis of superconducting Nb-Sn materials by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sitek, J.; Tomasich, M.; Cirak, J.; Prejsa, M.; Kruzliak, J.

    1978-01-01

    Moessbauer spectroscopy is used for the optimalization of superconducting Nb-Sn samples preparation in the form of foils. Pure phases of Nb 3 Sn, Nb 6 Sn 5 , and NbSn 2 are determined. Two series of samples are studied at 750 and 900 0 C tinning temperature respectively, and at 750, 860, 900, and 960 0 C heating temperatures. In the samples the phases Nb 3 Sn, Nb 6 Sn 5 , NbSn 2 , and the solid solution Nb-Sn phase are observed. The results from the phase analysis lead to the assumption that the percentage amount of the phases is preferentially dependent on the tinning temperature. (author)

  14. Superconductivity optimization and phase formation kinetics study of internal-Sn Nb3Sn superconducting wires

    International Nuclear Information System (INIS)

    Zhang, Chaowu

    2007-07-01

    Superconductors Nb 3 Sn wires are one of the most applicable cryogenic superconducting materials and the best choice for high-field magnets exceeding 10 T. One of the most significant utilization is the ITER project which is regarded as the hope of future energy source. The high-Cu composite designs with smaller number of sub-element and non-reactive diffusion barrier, and the RRP (Restacked Rod Process) internal-Sn technology are usually applied for the wire manufacturing. Such designed and processed wires were supplied by MSA/Alstom and WST/NIN in this research. The systematic investigation on internal-Sn superconducting wires includes the optimization of heat treatment (HT) conditions, phase formation and its relation with superconductivity, microstructure analysis, and the phase formation kinetics. Because of the anfractuosity of the configuration design and metallurgical processing, the MF wires are not sufficient for studying a sole factor effect on superconductivity. Therefore, four sets of mono-element (ME) wires with different Sn ratios and different third-element addition were designed and fabricated in order to explore the relationship between phase formation and superconducting performances, particularly the A15 layer growth kinetics. Different characterization technic have been used (magnetization measurements, neutron diffraction and SEM/TEM/EDX analysis). The A15 layer thicknesses of various ME samples were measured and carried out linear and non-linear fits by means of two model equations. The results have clearly demonstrated that the phase formation kinetics of Nb 3 Sn solid-state reaction is in accordance with an n power relation and the n value is increased with the increase of HT temperature and the Sn ratio in the wire composite. (author)

  15. Beta decays of 126Cd and 126In to levels in 126In and 126Sn

    International Nuclear Information System (INIS)

    Gartner, M.L.

    1979-01-01

    A study of the beta decays of 126 Cd and 126 In using the TRISTAN on-line isotope separator facility is reported. Gamma-ray singles measurements were made for both decays usng Ge(Li) and LEPS (low energy photon spectrometer) detectors. In addition, gamma--gamma coincidence measurements and gamma multiscale measurements were made for both decays using Ge(Li) detectors. The half-life for 126 Cd was determined to be 0.506 +- 0.015 sec., and the half-lives for the low- and high-spin 126 In isomers were determined to be 1.83 +- 0.11 sec. and 1.96 +- 0.10 sec., respectively. A total of 11 gamma rays were observed in the decay of 126 Cd, and all but one were placed in a level scheme for 126 In. A total of 48 gamma rays were observed in the decay of the low- and high-spin 126 In isomers and all were placed in a level scheme for 126 Sn. Spin and parity assignments were deduced, whenever possible, on the basis of logft values and gamma decay selection rules. The 126 In decay schemes (one has been proposed for each isomer) are compared with earlier decay studies and with results from 124 Sn(t,p) 126 Sn reaction experiments. The systematics associated with the level schemes are discussed and a comparison is made with the nuclear shell model. 49 references

  16. Directional Solidification and Liquidus Projection of the Sn-Co-Cu System

    Science.gov (United States)

    Chen, Sinn-Wen; Chang, Jui-Shen; Pan, Kevin; Hsu, Chia-Ming; Hsu, Che-Wei

    2013-04-01

    This study investigates the Sn-Co-Cu ternary system, which is of interest to the electronics industry. Ternary Sn-Co-Cu alloys were prepared, their as-solidified microstructures were examined, and their primary solidification phases were determined. The primary solidification phases observed were Cu, Co, Co3Sn2, CoSn, CoSn2, Cu6Sn5, Co3Sn2, γ, and β phases. Although there are ternary compounds reported in this ternary system, no ternary compound was found as the primary solidification phase. The directional solidification technique was applied when difficulties were encountered using the conventional quenching method to distinguish the primary solidification phases, such as Cu6Sn5, Cu3Sn, and γ phases. Of all the primary solidification phases, the Co3Sn2 and Co phases have the largest compositional regimes in which alloys display them as the primary solidification phases. There are four class II reactions and four class III reactions. The reactions with the highest and lowest reaction temperatures are both class III reactions, and are L + CoSn2 + Cu6Sn5 = CoSn3 at 621.5 K (348.3 °C) and L + Co3Sn2 + CoSn = Cu6Sn5 at 1157.8 K (884.6 °C), respectively.

  17. Carbon supported Pd-Sn and Pd-Ru-Sn nanocatalysts for ethanol electro-oxidation in alkaline medium

    CSIR Research Space (South Africa)

    Modibedi, RM

    2011-04-01

    Full Text Available Carbon supported Pd-Sn and Pd-Ru-Sn nanocatalysts were prepared by the chemical reduction method, using sodium borohydride and ethylene glycol mixture as the reducing agent. The catalytic activity towards ethanol electro-oxidation in alkaline medium...

  18. Spectroscopy of the doubly magic nucleus {sup 100}Sn and its decay

    Energy Technology Data Exchange (ETDEWEB)

    Hinke, Christoph B.

    2010-07-23

    The nucleus {sup 100}Sn has been the aim of a number of experimental approaches. It is of great interest for various reasons. It is presumably the heaviest particle-stable N=Z nucleus and at the same time doubly magic. Its beta decay is of particular importance because it is expected to be the purest Gamow-Teller decay in the nuclear chart and thus allows to study the question of the missing Gamow-Teller strength/the Gamow-Teller quenching due to core polarisation effects. From the beta-coincident decay spectroscopy of the daughter nucleus {sup 100}In information about the proton-neutron interaction in this region of the nuclear chart can be obtained. Simultaneously with the implantation of the nucleus in the detector setup after production the search for delayed gamma radiation from a predicted isomeric state in {sup 100}Sn could yield first insight into the structure of excited states in this exotic nucleus. This work presents investigation results concerning the spectroscopy of the doubly magic nucleus {sup 100}Sn and its decay. The experiment was performed in March 2008 at the accelerator facilities of the GSI Helmholtz Zentrum Darmstadt. The neutron deficient nucleus was produced in a projectile fragmentation reaction of a {sup 124}Xe primary beam impinging on a Beryllium target with an energy of 1 GeV x A. After a separation from other fragmentation products and a unique identification {sup 100}Sn was stopped in an implantation detector consisting of highly segmented silicon strip detectors for decay spectroscopy. Beside the determination of the half life it was possible to detect the total energy of the emitted particle radiation in the implantation detector as well as the emitted gamma radiation with a surrounding array of Germanium detectors. With a number of approximately 70 successfully observed decays of {sup 100}Sn a half life of T{sub 1/2}=1.16{+-}0.20s was obtained. The beta endpoint energy of the single channel decay yielded a value of E{sub {beta

  19. 119Sn MAS NMR Study of Probe Molecules Interaction with Sn-BEA: The Origin of Penta- and Hexacoordinated Tin Formation

    DEFF Research Database (Denmark)

    Yakimov, Alexander V.; G. Kolyagin, Yury; Tolborg, Søren

    2016-01-01

    and weak Lewis acidity, respectively. The adsorption of acetonitrile and methanol resulted in observation of pentacoordinated tin species, due to the formation of 1:1 adsorption complexes over both Sn-sites. Water adsorption led first to formation of pentacoordinated tin species, which were further...... by the formation of pentacoordinated Sn species in the case of weak sites and hexacoordinated Sn over sites with strong Lewis acidity, pointing to the possibility of dissociative adsorption of secondary alcohols over strong Sn-sites....

  20. Highly Active, Carbon-supported, PdSn Nano-core, Partially ...

    African Journals Online (AJOL)

    Carbon-supported, Pt partially covered, PdSn alloy nanoparticles (Pt-PdSn/C) were synthesized via a metathetical reaction of PdSn alloy nanoparticles, and a platinum precursor. The electrochemical activity was evaluated by methanol oxidation. The Pt-PdSn/C catalysts were characterized by transmission electron ...

  1. DO{sub 22}-(Cu,Ni){sub 3}Sn intermetallic compound nanolayer formed in Cu/Sn-nanolayer/Ni structures

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lilin [School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Huang, Haiyou [Department of Mechanical Engineering, Hong Kong University of Science and Technology (HKUST) (Hong Kong); Hong Kong - Beijing Joint Research Center, HKUST Fok Ying Tung Graduate School, Nansha, Guangzhou (China); Fu Ran; Liu Deming [ASM Assembly Automation Ltd. (Hong Kong); Zhang Tongyi, E-mail: mezhangt@ust.h [Department of Mechanical Engineering, Hong Kong University of Science and Technology (HKUST) (Hong Kong); Hong Kong - Beijing Joint Research Center, HKUST Fok Ying Tung Graduate School, Nansha, Guangzhou (China)

    2009-11-03

    The present work conducts crystal characterization by High Resolution Transmission Electron Microscopy (HRTEM) on Cu/Sn-nanolayer/Ni sandwich structures associated with the use of Energy Dispersive X-ray (EDX) analysis. The results show that DO{sub 22}-(Cu,Ni){sub 3}Sn intermetallic compound (IMC) ordered structure is formed in the sandwich structures at the as-electrodeposited state. The formed DO{sub 22}-(Cu,Ni){sub 3}Sn IMC is a homogeneous layer with a thickness about 10 nm. The DO{sub 22}-(Cu,Ni){sub 3}Sn IMC nanolayer is stable during annealing at 250 deg. C for 810 min. The formation and stabilization of the metastable DO{sub 22}-(Cu,Ni){sub 3}Sn IMC nanolayer are attributed to the less strain energy induced by lattice mismatch between the DO{sub 22} IMC and fcc Cu crystals in comparison with that between the equilibrium DO{sub 3} IMC and fcc Cu crystals.

  2. First Principles Investigation of the Mechanical, Thermodynamic and Electronic Properties of FeSn{sub 5} and CoSn{sub 5} Intermetallic Phases under Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wenming; Liu, Jing; Wang, Hong [China Building Materials Academy, Beijing (China); Zhang, Zhenwei [Linyi Academy of Technology Cooperation and Application, Linyi (China); Zhang, Liang [NeoTrident Technology Ltd., Shanghai (China); Bu, Yuxiang [Shandong University, Jinan (China)

    2017-02-15

    For guidance for developing Fe/Co-Sn-based anode materials for lithium-ion batteries, the mechanical, thermodynamic and electronic properties of FeSn{sub 5} and CoSn{sub 5} intermetallic phases under pressures ranging from 0 to 30 GPa have been investigated systematically using first-principles total-energy calculations within the framework of the generalized gradient approximation. The pressure was found to have significant effects on the mechanical, thermodynamic and electronic properties of these compounds. In the selected pressure range, CoSn{sub 5} has a more negative formation enthalpy than FeSn{sub 5}. Based on the calculated elastic constants, the bulk modulus, shear modulus, and Young's modulus were determined via the Viogt-Reuss-Hill averaging scheme. The variations of specific heats at constant volume for FeSn{sub 5} and CoSn{sub 5} in a wide pressure (0 - 30 GPa) and temperature (0 - 1000 K) range are also predicted from phonon density of states calculation. The calculated results suggested that both FeSn{sub 5} and CoSn{sub 5} are mechanically stable at pressure from 0 to 30 GPa. FeSn{sub 5} is dynamically stable at pressure up to, 30 GPa, at least, however, CoSn{sub 5} is dynamically stable no higher than 15 GPa.

  3. Study of Sn100-xMnx amorphous system by 119Sn Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Drago, V.

    1986-01-01

    Thin films of Sn 100-x Mn x amorphous alloys with large range of concentrations were procedure by vapor condensation technique on substrates at temperatures near to liquid helium. The magnetic and paramagnetic hyperfine spectra, and the ordering temperatures were measured by 119 Sn Moessbauer effect. The electrical resistivity was used for characterizing the amorphous state. All the measurements were done 'in situ'. A magnetic phase diagram is proposed. (M.C.K.) [pt

  4. The effect of intermetallic compound morphology on Cu diffusion in Sn-Ag and Sn-Pb solder bump on the Ni/Cu Under-bump metallization

    Science.gov (United States)

    Jang, Guh-Yaw; Duh, Jenq-Gong

    2005-01-01

    The eutectic Sn-Ag solder alloy is one of the candidates for the Pb-free solder, and Sn-Pb solder alloys are still widely used in today’s electronic packages. In this tudy, the interfacial reaction in the eutectic Sn-Ag and Sn-Pb solder joints was investigated with an assembly of a solder/Ni/Cu/Ti/Si3N4/Si multilayer structures. In the Sn-3.5Ag solder joints reflowed at 260°C, only the (Ni1-x,Cux)3Sn4 intermetallic compound (IMC) formed at the solder/Ni interface. For the Sn-37Pb solder reflowed at 225°C for one to ten cycles, only the (Ni1-x,Cux)3Sn4 IMC formed between the solder and the Ni/Cu under-bump metallization (UBM). Nevertheless, the (Cu1-y,Niy)6Sn5 IMC was observed in joints reflowed at 245°C after five cycles and at 265°C after three cycles. With the aid of microstructure evolution, quantitative analysis, and elemental distribution between the solder and Ni/Cu UBM, it was revealed that Cu content in the solder near the solder/IMC interface played an important role in the formation of the (Cu1-y,Niy)6Sn5 IMC. In addition, the diffusion behavior of Cu in eutectic Sn-Ag and Sn-Pb solders with the Ni/Cu UBM were probed and discussed. The atomic flux of Cu diffused through Ni was evaluated by detailed quantitative analysis in an electron probe microanalyzer (EPMA). During reflow, the atomic flux of Cu was on the order of 1016-1017 atoms/cm2sec in both the eutectic Sn-Ag and Sn-Pb systems.

  5. Nitrogen-Doped Carbon-Encapsulated SnO2@Sn Nanoparticles Uniformly Grafted on Three-Dimensional Graphene-like Networks as Anode for High-Performance Lithium-Ion Batteries.

    Science.gov (United States)

    Li, Yunyong; Zhang, Haiyan; Chen, Yiming; Shi, Zhicong; Cao, Xiaoguo; Guo, Zaiping; Shen, Pei Kang

    2016-01-13

    A peculiar nanostructure consisting of nitrogen-doped, carbon-encapsulated (N-C) SnO2@Sn nanoparticles grafted on three-dimensional (3D) graphene-like networks (designated as N-C@SnO2@Sn/3D-GNs) has been fabricated via a low-cost and scalable method, namely an in situ hydrolysis of Sn salts and immobilization of SnO2 nanoparticles on the surface of 3D-GNs, followed by an in situ polymerization of dopamine on the surface of the SnO2/3D-GNs, and finally a carbonization. In the composites, three-layer core-shell N-C@SnO2@Sn nanoparticles were uniformly grafted onto the surfaces of 3D-GNs, which promotes highly efficient insertion/extraction of Li(+). In addition, the outermost N-C layer with graphene-like structure of the N-C@SnO2@Sn nanoparticles can effectively buffer the large volume changes, enhance electronic conductivity, and prevent SnO2/Sn aggregation and pulverization during discharge/charge. The middle SnO2 layer can be changed into active Sn and nano-Li2O during discharge, as described by SnO2 + Li(+) → Sn + Li2O, whereas the thus-formed nano-Li2O can provide a facile environment for the alloying process and facilitate good cycling behavior, so as to further improve the cycling performance of the composite. The inner Sn layer with large theoretical capacity can guarantee high lithium storage in the composite. The 3D-GNs, with high electrical conductivity (1.50 × 10(3) S m(-1)), large surface area (1143 m(2) g(-1)), and high mechanical flexibility, tightly pin the core-shell structure of the N-C@SnO2@Sn nanoparticles and thus lead to remarkably enhanced electrical conductivity and structural integrity of the overall electrode. Consequently, this novel hybrid anode exhibits highly stable capacity of up to 901 mAh g(-1), with ∼89.3% capacity retention after 200 cycles at 0.1 A g(-1) and superior high rate performance, as well as a long lifetime of 500 cycles with 84.0% retention at 1.0 A g(-1). Importantly, this unique hybrid design is expected to be

  6. Adsorption and oxidation of acetaldehyde on carbon supported Pt, PtSn and PtSn-based trimetallic catalysts by in situ Fourier transform infrared spectroscopy

    Science.gov (United States)

    Beyhan, Seden; Léger, Jean-Michel; Kadırgan, Figen

    2013-11-01

    The adsorption and oxidation of acetaldehyde on carbon supported Pt, Pt90Sn10 and Pt80Sn10M10 (M = Ni, Co, Rh, Pd) catalysts have been investigated by using in situ Fourier transform infrared (FTIR) spectroscopy. The result revealed that Pt90Sn10/C catalyst is not very efficient for the conversion of acetaldehyde to CO2 due to the weak adsorption of acetaldehyde in the presence of Sn. However, the addition of a third metal to Pt--Sn facilitates the C-C bond cleavage of acetaldehyde. It seems that acetaldehyde is adsorbed dissociatively on the surface of Pt80Sn10Ni10/C, Pt80Sn10Co10/C, Pt80Sn10Rh10/C catalysts, producing CH3 and CHO adsorbate species, which can be further oxidized to CO2. However, the pathway forming CO2 for Pt80Sn10Pd10/C catalyst mainly originates from the oxidation of CH3CO species. Thus, the presence of third metal in the PtSn catalyst has a strong impact upon the acetaldehyde adsorption behaviour and its reaction products.

  7. Tin (Sn) for enhancing performance in silicon CMOS

    KAUST Repository

    Hussain, Aftab M.; Fahad, Hossain M.; Singh, Nirpendra; Sevilla, Galo T.; Schwingenschlö gl, Udo; Hussain, Muhammad Mustafa

    2013-01-01

    We study a group IV element: tin (Sn) by integrating it into silicon lattice, to enhance the performance of silicon CMOS. We have evaluated the electrical properties of the SiSn lattice by performing simulations using First-principle studies, followed by experimental device fabrication and characterization. We fabricated high-κ/metal gate based Metal-Oxide-Semiconductor capacitors (MOSCAPs) using SiSn as channel material to study the impact of Sn integration into silicon. © 2013 IEEE.

  8. Tin (Sn) for enhancing performance in silicon CMOS

    KAUST Repository

    Hussain, Aftab M.

    2013-10-01

    We study a group IV element: tin (Sn) by integrating it into silicon lattice, to enhance the performance of silicon CMOS. We have evaluated the electrical properties of the SiSn lattice by performing simulations using First-principle studies, followed by experimental device fabrication and characterization. We fabricated high-κ/metal gate based Metal-Oxide-Semiconductor capacitors (MOSCAPs) using SiSn as channel material to study the impact of Sn integration into silicon. © 2013 IEEE.

  9. Late-time Near-infrared Observations of SN 2005df

    Science.gov (United States)

    Diamond, Tiara R.; Hoeflich, Peter; Gerardy, Christopher L.

    2015-06-01

    We present late-time near-infrared (NIR) spectral evolution, at 200-400 days, for the Type Ia supernova SN 2005df. The spectra show numerous strong emission features of [Co ii], [Co iii], and [Fe ii] throughout the 0.8-1.8 μm region. As the spectrum ages, the cobalt features fade as would be expected from the decay of 56Co to 56Fe. We show that the strong and isolated [Fe ii] emission line at 1.644 μ {m} provides a unique tool to analyze NIR spectra of SNe Ia. Normalization of spectra to this line allows the separation of features produced by stable versus unstable isotopes of iron group elements. We develop a new method of determining the initial central density, {ρ }c, and the magnetic field, B, of the white dwarf (WD) using the width of the 1.644 μ {m} line. The line width (LW) is sensitive because of electron capture in the early stages of burning, which increases as a function of density. The sensitivity of the LW to B increases with time, and the effects of the magnetic field shift toward later times with decreasing {ρ }c. Through comparison with spherical models, the initial central density for SN 2005df is measured as {ρ }c=0.9(+/- 0.2)× {10}9 {g} {{cm}}-3, which corresponds to a WD close to the Chandrasekhar mass, with {M}{WD}=1.31(+/- 0.03) {M}⊙ and systematic error less than 0.04 {M}⊙. This error estimate is based on spherical models. We discuss the potential uncertainties due to multi-dimensional effects, mixing, and rotation. The latter two effects would increase the estimate of the WD mass. Within {M}{Ch} explosions, however, the central density found for SN 2005df is very low for a H-accretor, possibly suggesting a helium star companion or a tidally disrupted WD companion. As an alternative, we suggest mixing of the central region. We find some support for high initial magnetic fields of strength {10}6 {G} for SN 2005df, however, 0 {G} cannot be ruled out because of noise in the spectra combined with low {ρ }c. We discuss our findings in

  10. Phase formation in Mg-Sn-Si and Mg-Sn-Si-Ca alloys

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-17

    Research highlights: > The solidification paths of ternary and quaternary alloys are analyzed in detail, using the tool of thermodynamic calculations. > The precipitation sequence of phases and their amounts compare well with the microstructure of alloys. > The most efficient comparison to the experimental thermal analysis data is done by calculation of the enthalpy variation with temperature. > The viability of a procedure for the selection of multicomponent key samples is demonstrated for the development of the Mg-Ca-Si-Sn phase diagram. - Abstract: Experimental work is done and combined with the Calphad method to generate a consistent thermodynamic description of the Mg-Ca-Si-Sn quaternary system, validated for Mg-rich alloys. The viability of a procedure for the selection of multicomponent key samples is demonstrated for this multicomponent system. Dedicated thermal analysis with DTA/DSC on sealed samples is performed and the microstructure of slowly solidified alloys is analyzed using SEM/EDX. The thermodynamic description and phase diagram of the ternary Mg-Si-Sn system, developed in detail also in this work, deviates significantly from a previous literature proposal. The phase formation in ternary and quaternary alloys is analyzed using the tool of thermodynamic equilibrium and Scheil calculations for the solidification paths and compared with present experimental data. The significant ternary/quaternary solid solubilities of pertinent intermetallic phases are quantitatively introduced in the quaternary Mg-Ca-Si-Sn phase diagram and validated by experimental data.

  11. Semiconducting ZnSnN{sub 2} thin films for Si/ZnSnN{sub 2} p-n junctions

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Ruifeng [Hebei Engineering Laboratory of Photoelectronic Functional Crystals, Hebei University of Technology (HEBUT), Tianjin 300401 (China); Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, and Key Laboratory of Additive Manufacturing Materials of Zhejiang Province, Ningbo 315201 (China); Cao, Hongtao; Liang, Lingyan, E-mail: lly@nimte.ac.cn, E-mail: swz@hebut.edu.cn; Xie, Yufang; Zhuge, Fei; Zhang, Hongliang; Gao, Junhua; Javaid, Kashif [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, and Key Laboratory of Additive Manufacturing Materials of Zhejiang Province, Ningbo 315201 (China); Liu, Caichi; Sun, Weizhong, E-mail: lly@nimte.ac.cn, E-mail: swz@hebut.edu.cn [Hebei Engineering Laboratory of Photoelectronic Functional Crystals, Hebei University of Technology (HEBUT), Tianjin 300401 (China)

    2016-04-04

    ZnSnN{sub 2} is regarded as a promising photovoltaic absorber candidate due to earth-abundance, non-toxicity, and high absorption coefficient. However, it is still a great challenge to synthesize ZnSnN{sub 2} films with a low electron concentration, in order to promote the applications of ZnSnN{sub 2} as the core active layer in optoelectronic devices. In this work, polycrystalline and high resistance ZnSnN{sub 2} films were fabricated by magnetron sputtering technique, then semiconducting films were achieved after post-annealing, and finally Si/ZnSnN{sub 2} p-n junctions were constructed. The electron concentration and Hall mobility were enhanced from 2.77 × 10{sup 17} to 6.78 × 10{sup 17 }cm{sup −3} and from 0.37 to 2.07 cm{sup 2} V{sup −1} s{sup −1}, corresponding to the annealing temperature from 200 to 350 °C. After annealing at 300 °C, the p-n junction exhibited the optimum rectifying characteristics, with a forward-to-reverse ratio over 10{sup 3}. The achievement of this ZnSnN{sub 2}-based p-n junction makes an opening step forward to realize the practical application of the ZnSnN{sub 2} material. In addition, the nonideal behaviors of the p-n junctions under both positive and negative voltages are discussed, in hope of suggesting some ideas to further improve the rectifying characteristics.

  12. Structural properties and hyperfine characterization of Sn-substituted goethites

    Energy Technology Data Exchange (ETDEWEB)

    Larralde, A.L. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Ramos, C.P. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Arcondo, B. [Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850 (C1063ACV), Bs. As. (Argentina); Tufo, A.E. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Saragovi, C. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Sileo, E.E., E-mail: sileo@qi.fcen.uba.ar [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Pure and tin-doped goethites were synthesized from Sn(II) solutions at ambient pressure and 70 Degree-Sign C. Black-Right-Pointing-Pointer The Rietveld refinement of PXRD data indicated that Sn partially substituted the Fe(III) ions. Black-Right-Pointing-Pointer The substitution provoked unit cell expansion, and a distortion of the coordination polyhedron. Black-Right-Pointing-Pointer {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV). Black-Right-Pointing-Pointer {sup 57}Fe Moessbauer spectroscopy showed a lower magnetic coupling as tin concentration increased. - Abstract: Tin-doped goethites obtained by a simple method at ambient pressure and 70 Degree-Sign C were characterized by inductively coupled plasma atomic emission spectrometry, scanning electron microscopy, Rietveld refinement of powder X-ray diffraction data, and {sup 57}Fe and {sup 119}Sn Moessbauer spectroscopy. The particles size and the length to width ratios decreased with tin-doping. Sn partially substituted the Fe(III) ions provoking unit cell expansion and increasing the crystallinity of the particles with enlarged domains that grow in the perpendicular and parallel directions to the anisotropic broadening (1 1 1) axis. Intermetallic E, E Prime and DC distances also change although the variations are not monotonous, indicating different variations in the coordination polyhedron. In general, the Sn-substituted samples present larger intermetallic distances than pure goethite, and the greatest change is shown in the E Prime distance which coincides with the c-parameter. {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV) in the samples. On the other hand, Fe(II) presence was not detected by {sup 57}Fe Moessbauer spectroscopy, suggesting the existence of vacancies in the Sn-doped samples. A lower magnetic coupling is also evidenced from the average magnetic hyperfine field values obtained as tin

  13. SiSn diodes: Theoretical analysis and experimental verification

    KAUST Repository

    Hussain, Aftab M.; Wehbe, Nimer; Hussain, Muhammad Mustafa

    2015-01-01

    We report a theoretical analysis and experimental verification of change in band gap of silicon lattice due to the incorporation of tin (Sn). We formed SiSn ultra-thin film on the top surface of a 4 in. silicon wafer using thermal diffusion of Sn

  14. Single-Particle States in $^{133}$Sn

    CERN Multimedia

    Huck, A

    2002-01-01

    % IS338 \\\\ \\\\ It is suggested to investigate the $\\beta^- $-decay of $^{133}$In and $^{134}$In in order to determine the single-particle states in $^{133}$Sn, which are so far unknown and needed for the shell-model description of the region close to $^{132}$Sn. Large hyper-pure Ge-detectors will be used for the $\\gamma$-ray spectroscopy. In the experiments with $^{134}$In, delayed neutrons in coincidence with $\\gamma$-rays from excited states in $^{133}$Sn provide the opportunity for a very selective detection of the states in question.

  15. The tin-rich copper lithium stannides: Li{sub 3}Cu{sub 6}Sn{sub 4} and Li{sub 2}CuSn{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Fuertauer, Siegfried; Flandorfer, Hans [Vienna Univ. (Austria). Inst. of Inorganic Chemistry (Materials Chemisrty); Effenberger, Herta S. [Vienna Univ. (Austria). Inst. of Mineralogy and Crystallography

    2015-05-01

    The Sn rich ternary intermetallic compounds Li{sub 3}Cu{sub 6}Sn{sub 4} (CSD-427097) and Li{sub 2}CuSn{sub 2} (CSD-427098) were synthesized from the pure elements by induction melting and annealing at 400 C. Structural investigations were performed by powder- and single-crystal XRD. Li{sub 3}Cu{sub 6}Sn{sub 4} crystallizes in space group P6/mmm; it is structurally related to but not isotypic with MgFe{sub 6}Ge{sub 6} (a = 5.095(2) Aa, c = 9.524(3) Aa; wR{sub 2} = 0.059; 239 unique F{sup 2}-values, 17 free variables). Li{sub 3}Cu{sub 6}Sn{sub 4} is characterized by two sites with a mixed Cu:Sn occupation. In contrast to all other Cu-Li-Sn compounds known so far, any mixed occupation was found for Cu-Li pairs only. In addition, one Li site is only half occupied. The second Sn rich phase is Li{sub 2}CuSn{sub 2} (space group I4{sub 1}/amd, a = 4.4281(15) Aa, c = 19.416(4) Aa; wR{sub 2} = 0.033; 213 unique F{sup 2}-values, 12 atom free variables); it is the only phase in the Cu-Li-Sn system which is noted for full ordering. Both crystal structures exhibit 3D-networks which host Li atoms in channels. They are important for understanding the lithiation mechanism in Cu-Sn electrodes for Li-ion batteries.

  16. High-precision isotopic characterization of USGS reference materials by TIMS and MC-ICP-MS

    Science.gov (United States)

    Weis, Dominique; Kieffer, Bruno; Maerschalk, Claude; Barling, Jane; de Jong, Jeroen; Williams, Gwen A.; Hanano, Diane; Pretorius, Wilma; Mattielli, Nadine; Scoates, James S.; Goolaerts, Arnaud; Friedman, Richard M.; Mahoney, J. Brian

    2006-08-01

    The Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia has undertaken a systematic analysis of the isotopic (Sr, Nd, and Pb) compositions and concentrations of a broad compositional range of U.S. Geological Survey (USGS) reference materials, including basalt (BCR-1, 2; BHVO-1, 2), andesite (AGV-1, 2), rhyolite (RGM-1, 2), syenite (STM-1, 2), granodiorite (GSP-2), and granite (G-2, 3). USGS rock reference materials are geochemically well characterized, but there is neither a systematic methodology nor a database for radiogenic isotopic compositions, even for the widely used BCR-1. This investigation represents the first comprehensive, systematic analysis of the isotopic composition and concentration of USGS reference materials and provides an important database for the isotopic community. In addition, the range of equipment at the PCIGR, including a Nu Instruments Plasma MC-ICP-MS, a Thermo Finnigan Triton TIMS, and a Thermo Finnigan Element2 HR-ICP-MS, permits an assessment and comparison of the precision and accuracy of isotopic analyses determined by both the TIMS and MC-ICP-MS methods (e.g., Nd isotopic compositions). For each of the reference materials, 5 to 10 complete replicate analyses provide coherent isotopic results, all with external precision below 30 ppm (2 SD) for Sr and Nd isotopic compositions (27 and 24 ppm for TIMS and MC-ICP-MS, respectively). Our results also show that the first- and second-generation USGS reference materials have homogeneous Sr and Nd isotopic compositions. Nd isotopic compositions by MC-ICP-MS and TIMS agree to within 15 ppm for all reference materials. Interlaboratory MC-ICP-MS comparisons show excellent agreement for Pb isotopic compositions; however, the reproducibility is not as good as for Sr and Nd. A careful, sequential leaching experiment of three first- and second-generation reference materials (BCR, BHVO, AGV) indicates that the heterogeneity in Pb isotopic compositions

  17. Origin of low thermal conductivity in SnSe

    Science.gov (United States)

    Xiao, Yu; Chang, Cheng; Pei, Yanling; Wu, Di; Peng, Kunling; Zhou, Xiaoyuan; Gong, Shengkai; He, Jiaqing; Zhang, Yongsheng; Zeng, Zhi; Zhao, Li-Dong

    2016-09-01

    We provide direct evidence to understand the origin of low thermal conductivity of SnSe using elastic measurements. Compared to state-of-the-art lead chalcogenides Pb Q (Q =Te , Se, S), SnSe exhibits low values of sound velocity (˜1420 m /s ) , Young's modulus (E ˜27.7 GPa ) , and shear modulus (G ˜9.6 GPa ) , which are ascribed to the extremely weak Sn-Se atomic interactions (or bonds between layers); meanwhile, the deduced average Grüneisen parameter γ of SnSe is as large as ˜3.13, originating from the strong anharmonicity of the bonding arrangement. The calculated phonon mean free path (l ˜ 0.84 nm) at 300 K is comparable to the lattice parameters of SnSe, indicating little room is left for further reduction of the thermal conductivity through introducing nanoscale microstructures and microscale grain boundaries. The low elastic properties indicate that the weak chemical bonding stiffness of SnSe generally causes phonon modes softening which eventually slows down phonon propagation. This work provides insightful data to understand the low lattice thermal conductivity of SnSe.

  18. Clinical evaluation of sup(99m)Tc-(Sn)-PI (sup(99m)Tc-(Sn)-pyridoxylidene isoleucine) in the various hepatobiliary disorders

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, S; Iio, M; Yamada, H; Murata, H; Chiba, K [Tokyo Metropolitan Geriatric Medical Center (Japan)

    1978-12-01

    The purpose of this study is to evaluate the hepatobiliary scanning using sup(99m)Tc-(Sn)-PI in clinical diagnosis of various hepatobiliary disorders. Nineteen patients were scanned with sup(99m)Tc-(Sn)-PI. The results were as follows: 1) The stability of sup(99m)Tc-(Sn)-PI examined by paper chromatography using saline as a solvent showed satisfied result at scanning time. sup(99m)Tc-(Sn)-PI in the blood was assumed to be bound to serum proteins immediately after injection. sup(99m)Tc-(Sn)-PI in the urine was assumed to keep the form of sup(99m)Tc-(Sn)-PI. 2) The appearance times of kidney, liver, bile duct, gallbladder, and intestine in the normal case were 5, 5, 10 and 15 minutes respectively after injection. The peak times of hepatogram in the normal case, drug induced hepatitis and obstructive jaundice were 12, 15 and 18 minutes respectively after injection. The images obtained by sup(99m)Tc-(Sn)-PI was superior to the images obtained by /sup 131/I-BSP. 3) The blood clearance and urinary excretion rate of sup(99m)Tc-(Sn)-PI also provided us clinical usefulness. 4) The scanning of Dubin-Johnson syndrome of sup(99m)Tc-(Sn)-PI showed almost normal hepatobiliary image similar to the sequential scan by /sup 131/I-RB as was reported previously by authors. In conclusion, the hepatobiliary scan using sup(99m)Tc-(Sn)-PI provided clear hepatobiliary images. Other parameters such as blood clearance, urinary excretion rate and diameter of choledochus were also favorable. By combining it with sup(99m)Tc-HIDA a differential diagnosis of congenital jaundice is also expected.

  19. Clinical evaluation of sup(99m)Tc-(Sn)-PI [sup(99m)Tc-(Sn)-pyridoxylidene isoleucine] in the various hepatobiliary disorders

    International Nuclear Information System (INIS)

    Kawaguchi, Schinichiro; Iio, Masahiro; Yamada, Hideo; Murata, Hajime; Chiba, Kazuo

    1978-01-01

    The purpose of this study is to evaluate the hepatobiliary scanning using sup(99m)Tc-(Sn)-PI in clinical diagnosis of various hepatobiliary disorders. Nineteen patients were scanned with sup(99m)Tc-(Sn)-PI. The results were as follows: 1) The stability of sup(99m)Tc-(Sn)-PI examined by paper chromatography using saline as a solvent showed satisfied result at scanning time. sup(99m)Tc-(Sn)-PI in the blood was assumed to be bound to serum proteins immediately after injection. sup(99m)Tc-(Sn)-PI in the urine was assumed to keep the form of sup(99m)Tc-(Sn)-PI. 2) The appearance times of kidney, liver, bile duct, gallbladder, and intestine in the normal case were 5, 5, 10 and 15 minutes respectively after injection. The peak times of hepatogram in the normal case, drug induced hepatitis and obstructive jaundice were 12, 15 and 18 minutes respectively after injection. The images obtained by sup(99m)Tc-(Sn)-PI was superior to the images obtained by 131 I-BSP. 3) The blood clearance and urinary excretion rate of sup(99m)Tc-(Sn)-PI also provided us clinical usefulness. 4) The scanning of Dubin-Johnson syndrome of sup(99m)Tc-(Sn)-PI showed almost normal hepatobiliary image similar to the sequential scan by 131 I-RB as was reported previously by authors. In conclusion, the hepatobiliary scan using sup(99m)Tc-(Sn)-PI provided clear hepatobiliary images. Other parameters such as blood clearance, urinary excretion rate and diameter of choledochus were also favorable. By combining it with sup(99m)Tc-HIDA a differential diagnosis of congenital jaundice is also expected. (author)

  20. Hydroponics on a chip: analysis of the Fe deficient Arabidopsis thylakoid membrane proteome.

    Science.gov (United States)

    Laganowsky, Arthur; Gómez, Stephen M; Whitelegge, Julian P; Nishio, John N

    2009-04-13

    The model plant Arabidopsis thaliana was used to evaluate the thylakoid membrane proteome under Fe-deficient conditions. Plants were cultivated using a novel hydroponic system, called "hydroponics on a chip", which yields highly reproducible plant tissue samples for physiological analyses, and can be easily used for in vivo stable isotope labeling. The thylakoid membrane proteome, from intact chloroplasts isolated from Fe-sufficient and Fe-deficient plants grown with hydroponics on a chip, was analyzed using liquid chromatography coupled to mass spectrometry. Intact masses of thylakoid membrane proteins were measured, many for the first time, and several proteins were identified with post-translational modifications that were altered by Fe deficiency; for example, the doubly phosphorylated form of the photosystem II oxygen evolving complex, PSBH, increased under Fe-deficiency. Increased levels of photosystem II protein subunit PSBS were detected in the Fe-deficient samples. Antioxidant enzymes, including ascorbate peroxidase and peroxiredoxin Q, were only detected in the Fe-deficient samples. We present the first biochemical evidence that the two major LHC IIb proteins (LHCB1 and LHCB2) may have significantly different functions in the thylakoid membrane. The study illustrates the utility of intact mass proteomics as an indispensable tool for functional genomics. "Hydroponics on a chip" provides the ability to grow A. thaliana under defined conditions that will be useful for systems biology.

  1. LED Die-Bonded on the Ag/Cu Substrate by a Sn-BiZn-Sn Bonding System

    Science.gov (United States)

    Tang, Y. K.; Hsu, Y. C.; Lin, E. J.; Hu, Y. J.; Liu, C. Y.

    2016-12-01

    In this study, light emitting diode (LED) chips were die-bonded on a Ag/Cu substrate by a Sn-BixZn-Sn bonding system. A high die-bonding strength is successfully achieved by using a Sn-BixZn-Sn ternary system. At the bonding interface, there is observed a Bi-segregation phenomenon. This Bi-segregation phenomenon solves the problems of the brittle layer-type Bi at the joint interface. Our shear test results show that the bonding interface with Bi-segregation enhances the shear strength of the LED die-bonding joints. The Bi-0.3Zn and Bi-0.5Zn die-bonding cases have the best shear strength among all die-bonding systems. In addition, we investigate the atomic depth profile of the deposited Bi-xZn layer by evaporating Bi-xZn E-gun alloy sources. The initial Zn content of the deposited Bi-Zn alloy layers are much higher than the average Zn content in the deposited Bi-Zn layers.

  2. {sup 119}Sn NMR investigations on superconducting Ca{sub 3}Ir{sub 4}Sn{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Rajib; Brueckner, Felix; Guenther, Marco; Klauss, Hans-Henning [IFP, TU Dresden (Germany); Petrovic, Cedomir; Wang, Kefeng [CMPMS, BNL, Upton, NY (United States); Luetkens, Hubertus; Biswas, Pabitra; Morenzoni, Elvezio; Amato, Alex [PSI, Villigen (Switzerland)

    2014-07-01

    Ca{sub 3}Ir{sub 4}Sn{sub 13} was found to exhibit superconducting transition with T{sub c} ∼ 7 K. It received considerable attention due to the possible coexistence of superconductivity and ferromagnetic spin fluctuation as well as the three-dimensional charge density wave (CDW) from the superlattice transition. While thermal, transport, and thermodynamic characterization of Ca{sub 3}Ir{sub 4}Sn{sub 13} single crystals suggest that it is a weakly correlated nodeless superconductor, recent μSR investigation reveals that the electron-phonon pairing interaction is in the strong-coupling limit. Here we present {sup 119}Sn NMR investigations on Ca{sub 3}Ir{sub 4}Sn{sub 13} polycrystalline samples and discuss the symmetry of the superconducting order parameter together with the normal state properties. Our preliminary results of spin-lattice relaxation rate (1/T{sub 1}) indicate that this is a BCS superconductor with weak-coupling limit.

  3. Voids, nanochannels and formation of nanotubes with mobile Sn fillings in Sn doped ZnO nanorods

    International Nuclear Information System (INIS)

    Ortega, Y; Dieker, Ch; Jaeger, W; Piqueras, J; Fernandez, P

    2010-01-01

    ZnO nanorods containing different hollow structures have been grown by a thermal evaporation-deposition method with a mixture of ZnS and SnO 2 powders as precursor. Transmission electron microscopy shows rods with rows of voids as well as rods with empty channels along the growth axis. The presence of Sn nanoprecipitates associated with the empty regions indicates, in addition, that these are generated by diffusion processes during growth, probably due to an inhomogeneous distribution of Sn. The mechanism of forming voids and precipitates appears to be based on diffusion processes similar to the Kirkendall effect, which can lead to void formation at interfaces of bulk materials or in core-shell nanostructures. In some cases the nanorods are ZnO tubes partially filled with Sn that has been found to melt and expand by heating the nanotubes under the microscope electron beam. Such metal-semiconductor nanostructures have potential applications as thermal nanosensors or as electrical nanocomponents.

  4. Volcanic-plutonic connections and metal fertility of highly evolved magma systems: A case study from the Herberton Sn-W-Mo Mineral Field, Queensland, Australia

    Science.gov (United States)

    Cheng, Yanbo; Spandler, Carl; Chang, Zhaoshan; Clarke, Gavin

    2018-03-01

    Understanding the connection between the highly evolved intrusive and extrusive systems is essential to explore the evolution of high silicic magma systems, which plays an important role in discussions of planetary differentiation, the growth of continents, crustal evolution, and the formation of highly evolved magma associated Sn-W-Mo mineral systems. To discern differences between "fertile" and "non-fertile" igneous rocks associated with Sn-W-Mo mineralization and reveal the genetic links between coeval intrusive and extrusive rocks, we integrate whole rock geochemistry, geochronology and Hf isotope signatures of igneous zircons from contemporaneous plutonic and volcanic rocks from the world-class Herberton Mineral Field of Queensland, Australia. The 310-300 Ma intrusive rocks and associated intra-plutonic W-Mo mineralization formed from relatively oxidized magmas after moderate degrees of crystal fractionation. The geochemical and isotopic features of the coeval volcanic succession are best reconciled utilizing the widely-accepted volcanic-plutonic connection model, whereby the volcanic rocks represent fractionated derivatives of the intrusive rocks. Older intrusions emplaced at 335-315 Ma formed from relatively low fO2 magmas that fractionated extensively to produce highly evolved granites that host Sn mineralization. Coeval volcanic rocks of this suite are compositionally less evolved than the intrusive rocks, thereby requiring a different model to link these plutonic-volcanic sequences. In this case, we propose that the most fractionated magmas were not lost to volcanism, but instead were effectively retained at the plutonic level, which allowed further localized build-up of volatiles and lithophile metals in the plutonic environment. This disconnection to the volcanism and degassing may be a crucial step for forming granite-hosted Sn mineralization. The transition between these two igneous regimes in Herberton region over a ∼30 m.y. period is attributed to

  5. Research and development studies into isotope production using the Harwell Variable Energy Cyclotron

    International Nuclear Information System (INIS)

    Nichols, A.L.; Bett, R.; Cuninghame, J.G.; Goodall, J.A.B.; Hill, J.I.S.; Sims, H.E.; Willis, H.H.

    1979-11-01

    Many useful radioisotopes can be produced by means of the Harwell Chemistry Division's Variable Energy Cyclotron. This report describes the preliminary preparation of a number of these neutron deficient isotopes (i.e. F18, S38, Fe52, Sr82-Rb82, Nb92m, Rh99, I123, Xe125, Tl201, Pu236, Pu237). Recently a targetry development programme has been initiated to optimise isotope yields. Gas, liquid and solid targets have been designed that can be quickly and safely removed from the cyclotron beam-line so that the target activity can be rapidly processed after the irradiation, if necessary. (author)

  6. Effects of annealing on evaporated SnS thin films

    International Nuclear Information System (INIS)

    Samsudi Sakrani; Bakar Ismail

    1994-01-01

    The effects of annealing of evaporated tin sulphide thin films (SnS) are described. The films were initially deposited onto glass substrate, followed by annealing in an encapsulated carbon block under the running argon gas at 310 degree Celsius. Short time annealing of the films results in a slight change of the compositions to a mix SnS/SnS sub 2 compound, and the tendency of increasing SnS sub 2 formation was observed on the films annealed for longer periods up to 20 hours. X-ray results showed the transformation of SnS peaks (040) and (080) to predominantly SnS sub 2 peaks - (001), (100), (101), and (110). The associated absorption coefficients measured on the films were found to be greater than 10 sup 5 cm sup -1, with indication of higher photon energy leading to the formation of SnS sub 2 compound

  7. Effects of annealing on evaporated SnS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sakrani, Samsudi; Ismail, Bakar [Universiti Teknologi Malaysia, Skudai, Johor Bahru (Malaysia). Dept. of Physics

    1994-12-31

    The effects of annealing of evaporated tin sulphide thin films (SnS) are described. The films were initially deposited onto glass substrate, followed by annealing in an encapsulated carbon block under the running argon gas at 310 degree Celsius. Short time annealing of the films results in a slight change of the compositions to a mix SnS/SnS sub 2 compound, and the tendency of increasing SnS sub 2 formation was observed on the films annealed for longer periods up to 20 hours. X-ray results showed the transformation of SnS peaks (040) and (080) to predominantly SnS sub 2 peaks - (001), (100), (101), and (110). The associated absorption coefficients measured on the films were found to be greater than 10 sup 5 cm sup -1, with indication of higher photon energy leading to the formation of SnS sub 2 compound.

  8. Spallation production of neutron deficient radioisotopes in North America

    International Nuclear Information System (INIS)

    Jamriska, D.J.; Peterson, E.J.; Carty, J.

    1997-01-01

    The US Department of Energy produces a number of neutron deficient radioisotopes by high energy proton induced spallation reactions in accelerators at Los Alamos National Laboratory in New Mexico and Brookhaven National Laboratory in New York. Research isotopes are also recovered from targets irradiated at TRIUMF in British Columbia, Canada. The radioisotopes recovered are distributed for use in nuclear medicine, environmental research, physics research, and industry worldwide. In addition to the main product line of Sr-82 from either Mo or Rb targets, Cu-67 from ZnO targets, and Ge-68 and RbBr targets, these irradiation facilities also produce some unique isotopes in quantities not available from any other source such as Al-26, Mg-28, Si-32, Ti-44, Fe-52, Gd-148, and Hg-194. The authors will describe the accelerator irradiation facilities at the Los Alamos and Brookhaven National Laboratories. The high level radiochemical processing facilities at Los Alamos and brief chemical processes will be described

  9. Syntheses, structural variants and characterization of AInM′S{sub 4} (A=alkali metals, Tl; M′ = Ge, Sn) compounds; facile ion-exchange reactions of layered NaInSnS{sub 4} and KInSnS{sub 4} compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yohannan, Jinu P.; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

    2016-06-15

    Ten AInM′S{sub 4} (A=alkali metals, Tl; M′= Ge, Sn) compounds with diverse structure types have been synthesized and characterized by single crystal and powder X-ray diffraction and a variety of spectroscopic methods. They are wide band gap semiconductors. KInGeS{sub 4}(1-β), RbInGeS{sub 4}(2), CsInGeS{sub 4}(3-β), TlInGeS{sub 4}(4-β), RbInSnS{sub 4}(8-β) and CsInSnS{sub 4}(9) compounds with three-dimensional BaGa{sub 2}S{sub 4} structure and CsInGeS{sub 4}(3-α) and TlInGeS{sub 4}(4-α) compounds with a layered TlInSiS{sub 4} structure have tetrahedral [InM′S{sub 4}]{sup −} frameworks. On the other hand, LiInSnS{sub 4}(5) with spinel structure and NaInSnS{sub 4}(6), KInSnS{sub 4}(7), RbInSnS{sub 4}(8-α) and TlInSnS{sub 4}(10) compounds with layered structure have octahedral [InM′S{sub 4}]{sup −} frameworks. NaInSnS{sub 4}(6) and KInSnS{sub 4}(7) compounds undergo facile topotactic ion-exchange, at room temperature, with various mono-, di- and tri-valent cations in aqueous medium to give rise to metastable layered phases. - Graphical abstract: NaInSnS{sub 4} and KInSnS{sub 4} compounds undergo, in aqueous medium at room temperature, facile topotactic ion-exchange with mono, di and trivalent cations. Display Omitted - Highlights: • Ten AInM′S{sub 4} compounds with diverse structure types were synthesized. • They are wide band gap semiconductors. • NaInSnS{sub 4} and KInSnS{sub 4} compounds undergo facile topotactic ion-exchange at room temperature.

  10. Insight into the Effect of Sn on CO and Formic Acid Oxidation at PtSn Catalysts

    DEFF Research Database (Denmark)

    Stevanović, S.; Tripković, D.; Tripkovic, Vladimir

    2014-01-01

    The role of Sn on the catalytic activity for CO and formic acid oxidation is studied by comparing the activities of differently treated PtSn/C and Pt/C catalysts. The catalysts are prepared by a microwave-assisted polyol synthesis method. As revealed by scanning tunneling and transmission electron...

  11. Structural, magnetic and transport properties of Mn3.1Sn0.9 and Mn3.1Sn0.9N compounds

    International Nuclear Information System (INIS)

    Feng, W.J.; Li, D.; Ren, W.J.; Li, Y.B.; Li, W.F.; Li, J.; Zhang, Y.Q.; Zhang, Z.D.

    2007-01-01

    The cubic anti-perovskite Mn 3.1 Sn 0.9 N compound is prepared via nitrogenation of the hexagonal Mn 3.1 Sn 0.9 compound. A magnetic phase diagram of Mn 3.1 Sn 0.9 compound is constructed by analysis of data of its magnetic properties. For Mn 3.1 Sn 0.9 N compound, parasitic ferromagnetism exists in the temperature range of 5-370 K, besides a spin-reorientation at about 280 K. Mn 3.1 Sn 0.9 compound exhibits a metallic conducting behavior, while Mn 3.1 Sn 0.9 N displays a metal-nonmetal transition due to the electron localization caused by the static disorder. The differences of the physical properties between the both compounds, are discussed, in terms of the correlation of the hexagonal DO 19 and the cubic anti-perovskite structures, the reduction of the distances between Mn atoms, and the spin-pairing or charge transfer effect due to the electron donation by N 2p to Mn 3d states after introduction of N atoms into the interstitial sites of Mn 3.1 Sn 0.9 compound

  12. Studying superconducting Nb3Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb3Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb3Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  13. Studying superconducting Nb$_{3}$Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb$_{3}$Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb$_{3}$Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  14. Superconductivity optimization and phase formation kinetics study of internal-Sn Nb{sub 3}Sn superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chaowu

    2007-07-15

    Superconductors Nb{sub 3}Sn wires are one of the most applicable cryogenic superconducting materials and the best choice for high-field magnets exceeding 10 T. One of the most significant utilization is the ITER project which is regarded as the hope of future energy source. The high-Cu composite designs with smaller number of sub-element and non-reactive diffusion barrier, and the RRP (Restacked Rod Process) internal-Sn technology are usually applied for the wire manufacturing. Such designed and processed wires were supplied by MSA/Alstom and WST/NIN in this research. The systematic investigation on internal-Sn superconducting wires includes the optimization of heat treatment (HT) conditions, phase formation and its relation with superconductivity, microstructure analysis, and the phase formation kinetics. Because of the anfractuosity of the configuration design and metallurgical processing, the MF wires are not sufficient for studying a sole factor effect on superconductivity. Therefore, four sets of mono-element (ME) wires with different Sn ratios and different third-element addition were designed and fabricated in order to explore the relationship between phase formation and superconducting performances, particularly the A15 layer growth kinetics. Different characterization technic have been used (magnetization measurements, neutron diffraction and SEM/TEM/EDX analysis). The A15 layer thicknesses of various ME samples were measured and carried out linear and non-linear fits by means of two model equations. The results have clearly demonstrated that the phase formation kinetics of Nb{sub 3}Sn solid-state reaction is in accordance with an n power relation and the n value is increased with the increase of HT temperature and the Sn ratio in the wire composite. (author)

  15. GeSn-on-insulator substrate formed by direct wafer bonding

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Dian; Wang, Wei; Gong, Xiao, E-mail: elegong@nus.edu.sg, E-mail: yeo@ieee.org; Yeo, Yee-Chia, E-mail: elegong@nus.edu.sg, E-mail: yeo@ieee.org [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Lee, Kwang Hong; Wang, Bing [Low Energy Electronic Systems (LEES), Singapore MIT Alliance for Research and Technology (SMART), 1 CREATE Way, #10-01 CREATE Tower, Singapore 138602 (Singapore); Bao, Shuyu [Low Energy Electronic Systems (LEES), Singapore MIT Alliance for Research and Technology (SMART), 1 CREATE Way, #10-01 CREATE Tower, Singapore 138602 (Singapore); School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Tan, Chuan Seng [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2016-07-11

    GeSn-on-insulator (GeSnOI) on Silicon (Si) substrate was realized using direct wafer bonding technique. This process involves the growth of Ge{sub 1-x}Sn{sub x} layer on a first Si (001) substrate (donor wafer) followed by the deposition of SiO{sub 2} on Ge{sub 1-x}Sn{sub x}, the bonding of the donor wafer to a second Si (001) substrate (handle wafer), and removal of the Si donor wafer. The GeSnOI material quality is investigated using high-resolution transmission electron microscopy, high-resolution X-ray diffraction (HRXRD), atomic-force microscopy, Raman spectroscopy, and spectroscopic ellipsometry. The Ge{sub 1-x}Sn{sub x} layer on GeSnOI substrate has a surface roughness of 1.90 nm, which is higher than that of the original Ge{sub 1-x}Sn{sub x} epilayer before transfer (surface roughness is 0.528 nm). The compressive strain of the Ge{sub 1-x}Sn{sub x} film in the GeSnOI is as low as 0.10% as confirmed using HRXRD and Raman spectroscopy.

  16. Phase composition of rapidly solidified Ag-Sn-Cu dental alloys

    International Nuclear Information System (INIS)

    Lecong Dzuong; Do Minh Nghiep; Nguyen van Dzan; Cao the Ha

    1996-01-01

    The phase composition of some rapidly solidified Ag-Sn-Cu dental alloys with different copper contents (6.22 wtpct) has been studied by XRD, EMPA and optical microscopy. The samples were prepared from melt-spun ribbons. The microstructure of the as-quenched ribbons was microcrystalline and consisted of the Ag sub 3 Sn, Ag sub 4 Sn, Cu sub 3 Sn and Cu sub 3 Sn sub 8 phases. Mixing with mercury (amalgamation) led to formation of the Ag sub 2 Hg sub 3, Sn sub 7 Hg and Cu sub 6 Sn sub 5 phases. The amount of copper atoms in the alloys played an important role in phase formation in the amalgams

  17. Phase Equilibria of the Sn-Ni-Si Ternary System and Interfacial Reactions in Sn-(Cu)/Ni-Si Couples

    Science.gov (United States)

    Fang, Gu; Chen, Chih-chi

    2015-07-01

    Interfacial reactions in Sn/Ni-4.5 wt.%Si and Sn-Cu/Ni-4.5 wt.%Si couples at 250°C, and Sn-Ni-Si ternary phase equilibria at 250°C were investigated in this study. Ni-Si alloys, which are nonmagnetic, can be regarded as a diffusion barrier layer material in flip chip packaging. Solder/Ni-4.5 wt.%Si interfacial reactions are crucial to the reliability of soldered joints. Phase equilibria information is essential for development of solder/Ni-Si materials. No ternary compound is present in the Sn-Ni-Si ternary system at 250°C. Extended solubility of Si in the phases Ni3Sn2 and Ni3Sn is 3.8 and 6.1 at.%, respectively. As more Si dissolves in these phases their lattice constants decrease. No noticeable ternary solubility is observed for the other intermetallics. Interfacial reactions in solder/Ni-4.5 wt.%Si are similar to those for solder/Ni. Si does not alter the reaction phases. No Si solubility in the reaction phases was detected, although rates of growth of the reaction phases were reduced. Because the alloy Ni-4.5 wt.%Si reacts more slowly with solders than pure Ni, the Ni-4.5 wt.%Si alloy could be a potential new diffusion barrier layer material for flip chip packaging.

  18. The selective catalytic reduction of NO with NH3 over a novel Ce-Sn-Ti mixed oxides catalyst: Promotional effect of SnO2

    Science.gov (United States)

    Yu, Ming'e.; Li, Caiting; Zeng, Guangming; Zhou, Yang; Zhang, Xunan; Xie, Yin'e.

    2015-07-01

    A series of novel catalysts (CexSny) for the selective catalytic reduction of NO by NH3 were prepared by the inverse co-precipitation method. The aim of this novel design was to improve the NO removal efficiency of CeTi by the introduction of SnO2. It was found that the Ce-Sn-Ti catalyst was much more active than Ce-Ti and the best Ce:Sn molar ratio was 2:1. Ce2Sn1 possessed a satisfied NO removal efficiency at low temperature (160-280 °C), while over 90% NO removal efficiency maintained in the temperature range of 280-400 °C at the gas hourly space velocity (GHSV) of 50,000 h-1. Besides, Ce2Sn1 kept a stable NO removal efficiency within a wide range of GHSV and a long period of reacting time. Meanwhile, Ce2Sn1 exhibited remarkable resistance to both respectively and simultaneously H2O and SO2 poisoning due to the introduction of SnO2. The promotional effect of SnO2 was studied by N2 adsorption-desorption, X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS) and H2 temperature programmed reduction (H2-TPR) for detail information. The characterization results revealed that the excellent catalytic performance of Ce2Sn1 was associated with the higher specific surface area, larger pore volume and poorer crystallization. Besides, the introduction of SnO2 could result in not only greater conversion of Ce4+ to Ce3+ but also the increase amount of chemisorbed oxygen, which are beneficial to improve the SCR activity. More importantly, a novel peak appearing at lower temperatures through the new redox equilibrium of 2Ce4+ + Sn2+ ↔ 2Ce3+ + Sn4+ and higher total H2 consumption can be obtained by the addition of SnO2. Finally, the possible reaction mechanism of the selective catalytic reduction over Ce2Sn1 was also proposed.

  19. Ethanol electrooxidation on novel carbon supported Pt/SnO{sub x}/C catalysts with varied Pt:Sn ratio

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, L. [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany); Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian (China); Colmenares, L.; Jusys, Z. [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany); Sun, G.Q. [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian (China)], E-mail: gqsun@dicp.ac.cn; Behm, R.J. [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany)], E-mail: juergen.behm@uni-ulm.de

    2007-12-01

    Novel carbon supported Pt/SnO{sub x}/C catalysts with Pt:Sn atomic ratios of 5:5, 6:4, 7:3 and 8:2 were prepared by a modified polyol method and characterized with respect to their structural properties (X-ray diffraction (XRD) and transmission electron microscopy (TEM)), chemical composition (XPS), their electrochemical properties (base voltammetry, CO{sub ad} stripping) and their electrocatalytic activity and selectivity for ethanol oxidation (ethanol oxidation reaction (EOR)). The data show that the Pt/SnO{sub x}/C catalysts are composed of Pt and tin oxide nanoparticles with an average Pt particle diameter of about 2 nm. The steady-state activity of the Pt/SnO{sub x}/C catalysts towards the EOR decreases with tin content at room temperature, but increases at 80 deg. C. On all Pt/SnO{sub x}/C catalysts, acetic acid and acetaldehyde represent dominant products, CO{sub 2} formation contributes 1-3% for both potentiostatic and potentiodynamic reaction conditions. With increasing potential, the acetaldehyde yield decreases and the acetic acid yield increases. The apparent activation energies of the EOR increase with tin content (19-29 kJ mol{sup -1}), but are lower than on Pt/C (32 kJ mol{sup -1}). The somewhat better performance of the Pt/SnO{sub x}/C catalysts compared to alloyed PtSn{sub x}/C catalysts is attributed to the presence of both sufficiently large Pt ensembles for ethanol dehydrogenation and C-C bond splitting and of tin oxide for OH generation. Fuel cell measurements performed for comparison largely confirm the results obtained in model studies.

  20. Crystal Structure, Optical, and Electrical Properties of SnSe and SnS Semiconductor Thin Films Prepared by Vacuum Evaporation Techniques for Solar Cell Applications

    Science.gov (United States)

    Ariswan; Sutrisno, H.; Prasetyawati, R.

    2017-05-01

    Thin films of SnSe and SnS semiconductors had been prepared by vacuum evaporation techniques. All prepared samples were characterized on their structure, optical, and electrical properties in order to know their application in technology. The crystal structure of SnSe and SnS was determined by X-Ray Diffraction (XRD) instrument. The morphology and chemical composition were obtained by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive of X-Ray Analysis (EDAX). The optical property such as band gap was determined by DR-UV-Vis (Diffuse Reflectance-Ultra Violet-Visible) spectroscopy, while the electrical properties were determined by measuring the conductivity by four probes method. The characterization results indicated that both SnSe and SnS thin films were polycrystalline. SnSe crystallized in an orthorhombic crystal system with the lattice parameters of a = 11.47 Å, b = 4.152 Å and c = 4.439 Å, while SnS had an orthorhombic crystal system with lattice parameters of a = 4.317 Å, b = 11.647 Å and c = 3.981 Å. Band gaps (Eg) of SnSe and SnS were 1.63 eV and 1.35 eV, respectively. Chemical compositions of both thin films were non-stoichiometric. Molar ratio of Sn : S was close to ideal which was 1 : 0.96, while molar ratio of Sn : S was 1 : 0.84. The surface morphology described the arrangement of the grains on the surface of the thin film with sizes ranging from 0.2 to 0.5 microns. Color similarity on the surface of the SEM images proved a homogenous thin layer.

  1. Production of radioactive ion beams and resonance ionization spectroscopy with the laser ion source at on-line isotope separator ISOLDE

    International Nuclear Information System (INIS)

    Fedosseev, V.N.; )

    2005-01-01

    Full text: The resonance ionisation laser ion source (RILIS) of the ISOLDE on-line isotope separation facility at CERN is based on the method of laser step-wise resonance ionisation of atoms in a hot metal cavity. Using the system of dye lasers pumped by copper vapour lasers the ion beams of many different metallic elements have been produced at ISOLDE with an ionization efficiency of up to 27%. The high selectivity of the resonance ionization is an important asset for the study of short-lived nuclides produced in targets bombarded by the proton beam of the CERN Booster accelerator. Radioactive ion beams of Be, Mg, Al, Mn, Ni, Cu, Zn, Ga, Ag, Cd, In, Sn, Sb, Tb, Yb, Tl, Pb and Bi have been generated with the RILIS. Setting the RILIS laser in the narrow line-width mode provides conditions for a high-resolution study of hyperfine structure and isotopic shifts of atomic lines for short-lived isotopes. The isomer selective ionization of Cu, Ag and Pb isotopes has been achieved by appropriate tuning of laser wavelengths

  2. Unexpected, spontaneous and selective formation of colloidal Pt 3Sn nanoparticles using organometallic Pt and Sn complexes

    KAUST Repository

    Boualleg, Malika; Baudouin, David; Basset, Jean-Marie; Bayard, Franç ois; Candy, Jean Pierre; Jumas, Jean Claude; Veyre, Laurent; Thieuleux, Chloé

    2010-01-01

    The facile and selective synthesis of small crystalline Pt3Sn alloy nanoparticles was performed at room temperature under H2, using a colloidal approach without the use of extra-stabilizing ligands. The Pt 3Sn alloy was found to be obtained

  3. 3D Flower-Like Hierarchitectures Constructed by SnS/SnS2 Heterostructure Nanosheets for High-Performance Anode Material in Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Zhiguo Wu

    2015-01-01

    Full Text Available Sn chalcogenides, including SnS, Sn2S3, and SnS2, have been extensively studied as anode materials for lithium batteries. In order to obtain one kind of high capacity, long cycle life lithium batteries anode materials, three-dimensional (3D flower-like hierarchitectures constructed by SnS/SnS2 heterostructure nanosheets with thickness of ~20 nm have been synthesized via a simple one-pot solvothermal method. The obtained samples exhibit excellent electrochemical performance as anode for Li-ion batteries (LIBs, which deliver a first discharge capacity of 1277 mAhg−1 and remain a reversible capacity up to 500 mAhg−1 after 50 cycles at a current of 100 mAg−1.

  4. Liquidus Projection and Thermodynamic Modeling of a Sn-Ag-Zn System

    Science.gov (United States)

    Chen, Sinn-wen; Chiu, Wan-ting; Gierlotka, Wojciech; Chang, Jui-shen; Wang, Chao-hong

    2017-12-01

    Sn-Ag-Zn alloys are promising Pb-free solders. In this study, the Sn-Ag-Zn liquidus projection was determined, and the Sn-Ag-Zn thermodynamic modeling was developed. Various Sn-Ag-Zn alloys were prepared. Their as-cast microstructures and primary solidification phases were examined. The invariant reaction temperatures of the ternary Sn-Ag-Zn system were determined. The liquidus projection of the Sn-Ag-Zn ternary system was constructed. It was found that the Sn-Ag-Zn ternary system has eight primary solidification phases: ɛ2-AgZn3, γ-Ag5Zn8, β-AgZn, ζ-Ag4Sn, (Ag), ɛ1-Ag3Sn, β-(Sn) and (Zn) phases. There are eight ternary invariant reactions, and the liquid + (Ag) = β-AgZn + ζ-Ag4Sn reaction is of the highest temperature at 935.5 K. Thermodynamic modeling of the ternary Sn-Ag-Zn system was also carried out in this study based on the thermodynamic models of the three constituent binary systems and the experimentally determined liquidus projection. The liquidus projection and the isothermal sections are calculated. The calculated and experimentally determined liquidus projections are in good agreement.

  5. The 20th anniversary of SN1987A

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, A [KEK, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaragi, 305-0801 (Japan)], E-mail: atsuto.suzuki@kek.jp

    2008-07-15

    Observation of a neutrino burst from the supernova, SN1987A opened a new window of observational astronomy by neutrinos. And the history showed that the SN1987A neutrino burst observation was the vanguard of successive discoveries of neutrino properties by Super-Kamiokande, SNO, K2K, KamLAND and so on. On the occasion of the SN1987A 20th anniversary, the backstage story up to the discovery of the SN1987A neutrino bursts is summarized, tracing the Kamiokande log-note and including the IMB, LSD and Baksan data.

  6. `Pd20Sn13' revisited: crystal structure of Pd6.69Sn4.31

    Directory of Open Access Journals (Sweden)

    Wilhelm Klein

    2015-07-01

    Full Text Available The crystal structure of the title compound was previously reported with composition `Pd20Sn13' [Sarah et al. (1981. Z. Metallkd, 72, 517–520]. For the original structure model, as determined from powder X-ray data, atomic coordinates from the isostructural compound Ni13Ga3Ge6 were transferred. The present structure determination, resulting in a composition Pd6.69Sn4.31, is based on single crystal X-ray data and includes anisotropic displacement parameters for all atoms as well as standard uncertainties for the atomic coordinates, leading to higher precision and accuracy for the structure model. Single crystals of the title compound were obtained via a solid-state reaction route, starting from the elements. The crystal structure can be derived from the AlB2 type of structure after removing one eighth of the atoms at the boron positions and shifting adjacent atoms in the same layer in the direction of the voids. One atomic site is partially occupied by both elements with a Pd:Sn ratio of 0.38 (3:0.62 (3. One Sn and three Pd atoms are located on special positions with site symmetry 2. (Wyckoff letter 3a and 3b.

  7. The Incredibly Long-Lived SN 2005ip

    Science.gov (United States)

    Fox, Ori

    2016-10-01

    Type IIn supernovae (SNe IIn) are defined by their relatively narrow spectral line features associated with a dense circumstellar medium (CSM) formed by the progenitor star. The nature of the progenitor and mass loss remains relatively unknown. Shock interaction with the dense CSM can often result in significant UV emission for several years post-explosion, thereby probing the CSM characteristics, progenitor mass loss history and, ultimately, the progenitor itself. The Type IIn SN 2005ip proves to be one of the most interesting and well-studied targets within this subclass. Compared to all other supernovae, SN 2005ip is the most luminous for its age. Now more than 11 years post-explosion, the SN has released >10^51 erg throughout its lifetime as the forward shock continues to collide with a dense CSM. Here we propose HST/STIS-MAMA UV observations of SN 2005ip to investigate the massive CSM. When accounting for the shock travel time, these observations will probe material lost from the progenitor more than 1000 years prior to the explosion. We already have a single HST/STIS spectrum of SN 2005ip from 2014, which was obtained while the shock was still within a higher mass regime. With just 5 orbits, a second spectrum will allow us to directly trace the evolution of the CSM and produce new constraints on the pre-SN mass-loss history. Coinciding with Cycle 24's UV Initiative, this program offers new insight regarding both the progenitor and explosion characteristics of the SN IIn subclass.

  8. Storage Pool Deficiencies

    Science.gov (United States)

    ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ...

  9. [Hyp-Au-Sn9(Hyp)3-Au-Sn9(Hyp)3-Au-Hyp]-: the longest intermetalloid chain compound of tin.

    Science.gov (United States)

    Binder, Mareike; Schrenk, Claudio; Block, Theresa; Pöttgen, Rainer; Schnepf, Andreas

    2017-10-12

    The reaction of the metalloid tin cluster [Sn 10 (Hyp) 4 ] 2- with (Ph 3 P)Au-SHyp (Hyp = Si(SiMe 3 ) 3 ) gave an intermetalloid cluster [Au 3 Sn 18 (Hyp) 8 ] - 1, which is the longest intermetalloid chain compound of tin to date. 1 shows a structural resemblance to binary AuSn phases, which is expected for intermetalloid clusters.

  10. Study on the P-odd asymmetry of longitudinally polarized neutron transmission in 117Sn, 233Th, 239Pu isotopes and natural mixture of Cl and Pb isotopes

    International Nuclear Information System (INIS)

    Abov, Yu.G.; Ermakov, O.N.; Karpikhin, I.L.; Krupchitskij, P.A.; Kuznetsov, Yu.Eh.; Perepelitsa, V.F.; Petrushin, V.I.

    1983-01-01

    The results of measurements of P-odd helicity dependence of the total cross-section a=(σsub(tot)sup(+)-σsub(tot)sup(-))/(σsub(tot)sup(+)+σsub(tot)sup(-)) for thermal neutrons on several targets are presented. The result for 117 Sn is a=(11.2+-2.6)x10 -6 . The upper limits for a in the region of several units of 10 -6 are obtained for 232 Th, 239 Pu, Cl (natural) and Pb (natural)

  11. A review and prospects for Nb3Sn superconductor development

    Science.gov (United States)

    Xu, Xingchen

    2017-09-01

    Nb3Sn superconductors have significant applications in constructing high-field (>10 T) magnets. This article briefly reviews development of Nb3Sn superconductor and proposes prospects for further improvement. It is shown that significant improvement of critical current density (J c) is needed for future accelerator magnets. After a brief review of the development of Nb3Sn superconductors, the factors controlling J c are summarized and correlated with their microstructure and chemistry. The non-matrix J c of Nb3Sn conductors is mainly determined by three factors: the fraction of current-carrying Nb3Sn phase in the non-matrix area, the upper critical field B c2, and the flux line pinning capacity. Then prospects to improve the three factors are discussed respectively. An analytic model was developed to show how the ratios of precursors determine the phase fractions after heat treatment, based on which it is predicted that the limit of current-carrying Nb3Sn fraction in subelements is ∼65%. Then, since B c2 is largely determined by the Nb3Sn stoichiometry, a thermodynamic/kinetic theory is presented to show what essentially determines the Sn content of Nb3Sn conductors. This theory explains the influences of Sn sources and Ti addition on stoichiometry and growth rate of Nb3Sn layers. Next, to improve flux pinning, previous efforts in this community to introduce additional pinning centers to Nb3Sn wires are reviewed, and an internal oxidation technique is described. Finally, prospects for further improvement of non-matrix J c of Nb3Sn conductors are discussed, and it is seen that the only opportunity for further significantly improving J c lies in improving flux pinning.

  12. The complex structure of liquid Cu{sub 6}Sn{sub 5} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Qin Jingyu; Gu Tingkun; Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Southern Campus, Jinan 250061 (China); Liu Hui [Shandong High Performance Computing Center, Shandong University, Southern Campus, Jinan 250061 (China)

    2009-04-15

    By applying ab initio molecular dynamics simulation to liquid Cu{sub 6}Sn{sub 5} alloy, the hetero-coordination tendency is discovered by Bathia-Thornton partial correlation functions and a chemical short-range parameter. However the local structural environment of Sn in l-Cu{sub 6}Sn{sub 5} alloy resembles that of liquid Sn by Voronoi analysis. A new feature, i.e. a subpeak in between the first and second peaks, is discovered by the present method which implies that topologically disordered {beta}-Sn-type structural units may exist in l-Cu{sub 6}Sn{sub 5} alloy. The local density states of electrons show that both Cu-Sn and Sn-Sn bonding exist in l-Cu{sub 6}Sn{sub 5} alloy. This work suggests that chemical short-range order between unlike atoms and self-coordination between Sn atoms coexists in l-Cu{sub 6}Sn{sub 5} alloy.

  13. The effect of gamma irradiation on thermoelectric power and thermal conductivity of Ln0.01Sn0.99Se (Ln-Pr,Tb,Er) single crystals

    International Nuclear Information System (INIS)

    Guseynov, D.I.; Murguzov, M.I.; Ismaylov, Sh.S.; Mamedova, R.F.

    2013-01-01

    The present paper contains research results on the effect of gamma irradiation on thermal electromotive force and thermal conductivity of Ln 0 .01Sn 0 .99Se (Ln-Pr,Tb,Er) crystals. It is studied some electrical properties of the samples obtained before and after irradiation in a wide temperature range (80-420 K). As a source it was used an isotope 60Co with photon energies 1.25 MeV, the radiation dose was 65 Mrad

  14. Prediction of activities of all components in the lead-free solder systems Bi-In-Sn and Bi-In-Sn-Zn

    International Nuclear Information System (INIS)

    Tao Dongping

    2008-01-01

    The activities of components of the ternary lead-free solder systems Al-Sn-Zn at 973 K, Zn-Cu-Sn at 1023 K and Bi-In-Sn at 1000 and 1050 K have been predicted by a novel molecular interaction volume model-MIVM and the results are in good agreement with experimental data. Then the activities of all components of the Bi-In-Sn at 550 K and the Bi-In-Sn-Zn quaternary system at 700 K have been further predicted and the results are reasonable and reliable. This shows that the model may be a superior alternative for describing interfacial chemical reactions between lead-free solder alloys and common base materials and for the calculation of their phase diagrams because MIVM has certain physical meaning from the viewpoint of statistical thermodynamics and requires only two infinite dilute activity coefficients for each sub-binary system

  15. Electromigration in 3D-IC scale Cu/Sn/Cu solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Cheng-En, E-mail: ceho1975@hotmail.com; Lee, Pei-Tzu; Chen, Chih-Nan; Yang, Cheng-Hsien

    2016-08-15

    The electromigration effect on the three-dimensional integrated circuits (3D-IC) scale solder joints with a Cu/Sn(25–50 μm)/Cu configuration was investigated using a field-emission scanning electron microscope (FE–SEM) combined with electron backscatter diffraction (EBSD) analysis system. Electron current stressing for a few days caused the pronounced accumulation of Cu{sub 6}Sn{sub 5} in specific Sn grain boundaries (GBs). The EBSD analysis indicated that both the β-Sn crystallographic orientation and GB orientation play dominant roles in this accumulation. The dependencies of the Cu{sub 6}Sn{sub 5} accumulation on the two above factors (i.e., Sn grain orientation and GB orientation) can be well rationalized via a proposed mathematic model based on the Huntington and Grone's electromigration theory with the Cu anisotropic diffusion data in a β-Sn lattice. - Highlights: • Anisotropic Cu electromigration in the 3D-IC scale microelectronic solder joints. • Pronounced accumulation of Cu{sub 6}Sn{sub 5} intermetallic in specific Sn grain boundaries. • A linear dependence of Cu{sub 6}Sn{sub 5} accumulation over the current stressing time. • β-Sn and grain boundary orientations are the dominant factors in Cu{sub 6}Sn{sub 5} accumulation.

  16. Single-Crystal Growth of Cl-Doped n-Type SnS Using SnCl2 Self-Flux.

    Science.gov (United States)

    Iguchi, Yuki; Inoue, Kazutoshi; Sugiyama, Taiki; Yanagi, Hiroshi

    2018-06-05

    SnS is a promising photovoltaic semiconductor owing to its suitable band gap energy and high optical absorption coefficient for highly efficient thin film solar cells. The most significant carnage is demonstration of n-type SnS. In this study, Cl-doped n-type single crystals were grown using SnCl 2 self-flux method. The obtained crystal was lamellar, with length and width of a few millimeters and thickness ranging between 28 and 39 μm. X-ray diffraction measurements revealed the single crystals had an orthorhombic unit cell. Since the ionic radii of S 2- and Cl - are similar, Cl doping did not result in substantial change in lattice parameter. All the elements were homogeneously distributed on a cleaved surface; the Sn/(S + Cl) ratio was 1.00. The crystal was an n-type degenerate semiconductor with a carrier concentration of ∼3 × 10 17 cm -3 . Hall mobility at 300 K was 252 cm 2 V -1 s -1 and reached 363 cm 2 V -1 s -1 at 142 K.

  17. Isotopes and the early evolution of the earth

    International Nuclear Information System (INIS)

    Russell, R.D.

    1980-01-01

    The observed isotopic ratios of lead, strontium, neodymium, helium, and argon contain information about the chemical abundances of selected parent and daughter elements in the outer parts of the Earth. By necessity, we observe these isotopic ratios at the Earth's surface, which is a small, highly evolved part of the Earth. The studies of such isotopic ratios permit inferences to be made about interactions between this crust and the upper mantle. Helium has been especially valuable for demonstrating that primordial materials are still being outgassed from the earth. Models based on the observed argon isotopic ratios have lead to contradictory conclusions about the existence of an early period of extensive outgassing of the Earth. Lead has been a particularly interesting element because the ratio of the parents, 235 U/ 238 U, was very different in the Earth's early history than it is now. Therefore there is the potential for determining constraints on the early history of the Earth. A number of recently published papers offering lead isotope interpretations that reflect on the Earth's early history are reviewed, with special reference to models that are based upon uni-directional and bi-directional exchange between a protocrust and a residual mantle. Geochemical parameters for uranium, thorium and lead can be inferred for two evolving systems, as well as rate constants for differentiation. The principal conclusions are that the differentiation process extended beyond the first quarter of the Earth's history, and that it is possible to reproduce exactly the apparent oceanic basalt isochron by a simple two-reservoir model. In particular, such a model can explain quantitatively the observed lead-207 deficiency in the oceanic basalts

  18. Ionic liquid-assisted sonochemical synthesis of SnS nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    García-Gómez, Nora A.; Parra-Arcieniega, Salomé M. de la; Garza-Tovar, Lorena L.; Torres-González, Luis C.; Sánchez, Eduardo M., E-mail: eduardo.sanchezcv@uanl.edu.mx

    2014-03-05

    Highlight: • Obtention of SnS nanostructures using novel ionic liquid assisted sonochemical method. • Influence of the (BMImBF{sub 4}) ionic liquid in SnS morphology. • Inhibitory effect in SnS crystallinity by structuring agents in ionic environments. -- Abstract: SnS nanoparticles have been successfully synthesized by the ionic liquid-assisted sonochemical method (ILASM). The starting reagents were anhydrous SnCl{sub 2}, thioacetamide, dissolved in ethanol and ionic liquid (IL)1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF{sub 4}) mixtures. Our experiments showed that IL plays an important role in the morphology of SnS. A 1:1 ethanol:IL mixture was found to yield the more interesting features. The lower concentration of Sn (II) in solution favored the presence of nanoplatelets. An increase in ultrasonic time favored crystalline degree and size as well. Also, the effect of additives as 3-mercaptopropionic acid, diethanolamine, ethylene glycol, and trioctyl phosphine oxide is reported. X-ray diffraction (XRD) and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis-DRS) were used to characterize the obtained products.

  19. Multifilamentary Cu-Nb3Sn superconductor wires

    International Nuclear Information System (INIS)

    Rodrigues, D.; Pinatti, D.G.

    1990-01-01

    This paper reports on one of the main technological problems concerning Nb 3 Sn superconducting wires production which is the optimization of heat treatments for the formation of the A-15 intermetallic compound. At the present work, Nb 3 Sn superconducting wire is produced by solid-liquid diffusion method which increases considerably the critical current values of the superconductor. Through this method, niobium, copper and Sn 7% wt Cu alloy are kept in the pure state. Thus, the method dispenses intermediate heat treatments of recrystallization during the manufacturing process of the wire. After the wire was ready, optimization work of heat treatments was accomplished aiming to obtain its best superconducting characteristics, Measurement of critical temperature, critical current versus magnetic field, normal and at room temperature resistivity were performed, as well as scanning electron microscopy for determination of Nb 3 Sn layers and transmission electron microscopy measurements of redetermining the grain sizes in Nb 3 Sn formed in each treatment. It was obtained critical current densities of 1.8 x 10 6 A/cm 2 in the Nb 3 Sn layer, at 10 Teslas and 4.2 K. The samples were analyzed by employing the superconducting collective flux pinning theories and a satisfactory agreement between the experimental and theoretical data was attained. The production process and the small size of the filaments used made a successful optimization of the wire possible

  20. Properties of Sn-doped TiO2 nanotubes fabricated by anodization of co-sputtered Ti–Sn thin films

    International Nuclear Information System (INIS)

    Kyeremateng, Nana Amponsah; Hornebecq, Virginie; Knauth, Philippe; Djenizian, Thierry

    2012-01-01

    Self-organized Sn-doped TiO 2 nanotubes (nts) were fabricated for the first time, by anodization of co-sputtered Ti and Sn thin films. This nanostructured material was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, UV–vis spectroscopy and transmission electron microscopy. Due to their remarkable properties, Sn-doped TiO 2 nts can find potential applications in Li-ion microbatteries, photovoltaics, and catalysis. Particularly, the electrochemical performance as an anode material for Li-ion microbatteries was evaluated in Li test cells. With current density of 70 μA cm −2 (1 C) and cut-off potential of 1 V, Sn-doped TiO 2 nts showed improved performance compared to simple TiO 2 nts, and differential capacity plots revealed that the material undergoes full electrochemical reaction as a Rutile-type TiO 2 .

  1. Evolving shape coexistence in the lead isotopes: The geometry of configuration mixing in nuclei

    International Nuclear Information System (INIS)

    Frank, Alejandro; Isacker, Piet van; Vargas, Carlos E.

    2004-01-01

    A matrix coherent-state approach is applied to the interacting boson model (IBM) with configuration mixing to describe the evolving geometry of neutron-deficient Pb isotopes. It is found that for small mixing with parameters determined previously, the potential energy surface of 186 Pb has three minima, which correspond to spherical, oblate, and prolate shapes, in agreement with recent measurements and mean-field calculations. Away from midshell, in the heavier Pb isotopes, no deformed minima occur. Our analysis suggests that the configuration-mixing IBM, used in conjunction with a matrix coherent-state method, may be a reliable tool for the study of geometric aspects of shape coexistence in nuclei

  2. First-principles study of ZnSnAs2-based dilute magnetic semiconductors

    Science.gov (United States)

    Kizaki, Hidetoshi; Morikawa, Yoshitada

    2018-02-01

    The electronic structure and magnetic properties of chalcopyrite Zn(Sn,TM)As2 and (Zn,TM)SnAs2 have been investigated by the Korringa-Kohn-Rostoker method combined with the coherent potential approximation within the local spin density approximation, where TM denotes a 3d transition metal element. We find that the half-metallic and high-spin ferromagnetic state can be obtained in Zn(Sn,V)As2, Zn(Sn,Cr)As2, Zn(Sn,Mn)As2, (Zn,V)SnAs2, and (Zn,Cr)SnAs2. The calculated result of Zn(Sn,Mn)As2 is in good agreement with the experimentally observed room-temperature ferromagnetism if we can control selective Mn doping at Sn sites. In addition, (Zn,V)SnAs2 and (Zn,Cr)SnAs2 are predicted to exhibit high-Curie-temperature ferromagnetism.

  3. Isotope-aided studies of the bioavailability of iron from Myanmar diets

    International Nuclear Information System (INIS)

    Khin Maung Naing; Myo Khin

    1992-01-01

    Iron deficiency is an important nutritional problem in Myanmar. The preliminary studies in this paper are to be used as a feasibility study for an iron fortification programme in Myanmar. This programme is now in the planning stages. This paper contains summaries of information gathered from a dietary survey, isotope-aided studies of the bioavailability of iron from the daily diet, and a work plan for fortifying table salt with iron. 6 refs, 6 tabs

  4. Corrosion Behaviour of Sn-based Lead-Free Solders in Acidic Solution

    Science.gov (United States)

    Nordarina, J.; Mohd, H. Z.; Ahmad, A. M.; Muhammad, F. M. N.

    2018-03-01

    The corrosion properties of Sn-9(5Al-Zn), Sn-Cu and SAC305 were studied via potentiodynamic polarization method in an acidic solution of 1 M hydrochloric acid (HCl). Sn-9(5Al-Zn) produced different polarization profile compared with Sn-Cu and SAC305. The morphological analysis showed that small, deep grooves shaped of corrosion product formed on top of Sn-9(5Al-Zn) solder while two distinctive structures of closely packed and loosely packed corrosion product formed on top of Sn-Cu and SAC305 solder alloys. Phase analysis revealed the formations of various corrosion products such as SnO and SnO2 mainly dominant on surface of solder alloys after potentiodynamic polarization in 1 M hydrochloric acid (HCl).

  5. Influence of Sn content on PtSn/C catalysts for electrooxidation of C{sub 1}-C{sub 3} alcohols: Synthesis, characterization, and electrocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hong; Choi, Sung Mook; Nam, Sang Hoon; Seo, Min Ho; Kim, Won Bae [Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea); Choi, Sun Hee [Pohang Accelerator Laboratory, San-31 Hyoja-dong, Pohang, Kyungbuk 790-984 (Korea)

    2008-07-16

    A series of carbon-supported bimetallic PtSn catalysts for the electrooxidation of C{sub 1}-C{sub 3} alcohols (i.e., methanol (C{sub 1}), ethanol (C{sub 2}), and 1-propanol (C{sub 3})) were prepared with different Pt:Sn atomic ratios using borohydride reduction method combined with freeze-drying procedure at room temperature. The catalysts were investigated by employing various physicochemical analyses: X-ray diffraction (XRD), transmission electron microscopy (TEM) and extended X-ray absorption fine structure (EXAFS) to investigate the structural modification, and X-ray photoelectron spectroscopy (XPS) and X-ray absorption-near-edge spectroscopy (XANES) to characterize the change in electronic features. The variation of Sn content by forming PtSn alloys causes significant structural and electronic modifications of Pt crystallites, resulting in increases of lattice parameter and decreases of the Pt 5d band vacancies with Sn content. Cyclic voltammetry (CV) measurements showed that the addition of Sn into the Pt catalyst promotes the electro-catalytic activities for the electrooxidations of C{sub 1}, C{sub 2}, and C{sub 3} alcohols, in which the maximum activities appeared at different Sn contents for the C{sub 1}-C{sub 3} alcohols. In particular, a shift in optimum Pt:Sn composition was observed in that the Sn content required to reach the maximum peak current density was increased with the increasing number of carbon atoms in the C{sub 1}-C{sub 3} alcohols. Both the geometric and electronic effects with variation of Sn content are in close relationship in the bimetallic PtSn catalysts, consequently affecting the electrocatalytic activities by showing volcano-type behaviors over the electrooxidation of the individual alcohol. (author)

  6. Superconductivity, carrier concentration, and the ionic model of Sn/sub 4/P/sub 3/ and Sn/sub 4/As/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Van Maaren, M H

    1969-06-01

    Superconductivity is reported for Sn/sub 4/P/sub 2.65/ at T/sub c/ 1.2/sup 0/K. Hall constant and reflectivity measurements indicate a mixed type of conduction for Sn/sub 4/P/sub 2.65/ and Sn/sub 3.80/ As/sub 3/. The ionic model of Geller and Hull is not applicable.

  7. Characteristics and heat treatment of cold-sprayed Al-Sn binary alloy coatings

    International Nuclear Information System (INIS)

    Ning, Xian-Jin; Kim, Jin-Hong; Kim, Hyung-Jun; Lee, Changhee

    2009-01-01

    In this study, Al-Sn binary alloy coatings were prepared with Al-5 wt.% Sn (Al-5Sn) and Al-10 wt.% Sn (Al-10Sn) gas atomized powders by low pressure and high pressure cold spray process. The microstructure and microhardness of the coatings were characterized. To understand the coarsening of tin in the coating, the as-sprayed coatings were annealed at 150, 200, 250 and 300 o C for 1 h, respectively. The effect of annealing on microstructure and the bond strength of the coatings were investigated. The results show that Al-5Sn coating can be deposited by high pressure cold spray with nitrogen while Al-10Sn can only be deposited by low pressure cold spray with helium gas. Both Al-5Sn and Al-10Sn coatings present dense structures. The fraction of Sn in as-sprayed coatings is consistent with that in feed stock powders. The coarsening and/or migration of Sn phase in the coatings were observed when the annealing temperature exceeds 200 deg. C. Furthermore, the microhardness of the coatings decreased significantly at the annealing temperature of 250 deg. C. EDXA analysis shows that the heat treatment has no significant effect on fraction of Sn phase in Al-5Sn coatings. Bonding strength of as-sprayed Al-10Sn coating is slightly higher than that of Al-5Sn coating. Annealing at 200 o C can increase the bonding strength of Al-5Sn coatings.

  8. The crystallographic growth directions of Sn whiskers

    International Nuclear Information System (INIS)

    Stein, J.; Welzel, U.; Leineweber, A.; Huegel, W.; Mittemeijer, E.J.

    2015-01-01

    The growth directions of 55 Sn whiskers, i.e. the crystallographic orientation parallel to the whisker-growth axes, were determined using (i) a focused ion beam microscope for the determination of the physical growth angles of the whiskers with respect to a specimen (reference) coordinate system and (ii) an electron backscatter detector in a scanning electron microscope for the determination of the crystallographic orientation of the whiskers. The Sn whiskers were found to grow preferentially along low-index directions of the β-Sn crystal structure. The experimental findings of this study (and most of the results presented in the literature as well) were explained by applying, in a modified way, the Hartman–Perdok concept of periodic bond chains, i.e. chains of strong bonds running uninterruptedly through the structure, to the Sn whisker-growth phenomenon

  9. Unusually large chemical potential shift in a degenerate semiconductor: Angle-resolved photoemission study of SnSe and Na-doped SnSe

    Science.gov (United States)

    Maeda, M.; Yamamoto, K.; Mizokawa, T.; Saini, N. L.; Arita, M.; Namatame, H.; Taniguchi, M.; Tan, G.; Zhao, L. D.; Kanatzidis, M. G.

    2018-03-01

    We have studied the electronic structure of SnSe and Na-doped SnSe by means of angle-resolved photoemission spectroscopy. The valence-band top reaches the Fermi level by the Na doping, indicating that Na-doped SnSe can be viewed as a degenerate semiconductor. However, in the Na-doped system, the chemical potential shift with temperature is unexpectedly large and is apparently inconsistent with the degenerate semiconductor picture. The large chemical potential shift and anomalous spectral shape are key ingredients for an understanding of the novel metallic state with the large thermoelectric performance in Na-doped SnSe.

  10. Effect of indium and antimony doping in SnS single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Chaki, Sunil H., E-mail: sunilchaki@yahoo.co.in; Chaudhary, Mahesh D.; Deshpande, M.P.

    2015-03-15

    Highlights: • Single crystals growth of pure SnS, indium doped SnS and antimony doped SnS by direct vapour transport (DVT) technique. • Doping of In and Sb occurred in SnS single crystals by cation replacement. • The replacement mechanism ascertained by EDAX, XRD and substantiated by Raman spectra analysis. • Dopants concentration affects the optical energy bandgap. • Doping influences electrical transport properties. - Abstract: Single crystals of pure SnS, indium (In) doped SnS and antimony (Sb) doped SnS were grown by direct vapour transport (DVT) technique. Two doping concentrations of 5% and 15% each were employed for both In and Sb dopants. Thus in total five samples were studied viz., pure SnS (S1), 5% In doped SnS (S2), 15% In doped SnS (S3), 5% Sb doped SnS (S4) and 15% Sb doped SnS (S5). The grown single crystal samples were characterized by evaluating their surface microstructure, stoichiometric composition, crystal structure, Raman spectroscopy, optical and electrical transport properties using appropriate techniques. The d.c. electrical resistivity and thermoelectric power variations with temperature showed semiconducting and p-type nature of the as-grown single crystal samples. The room temperature Hall Effect measurements further substantiated the semiconducting and p-type nature of the as-grown single crystal samples. The obtained results are deliberated in detail.

  11. Deformation properties of lead isotopes

    International Nuclear Information System (INIS)

    Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E.

    2016-01-01

    The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF 0 Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, 180 Pb and 184 Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF 0 functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF 0 functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron-rich lead isotopes undergo

  12. Decay studies of the highly neutron-deficient indium isotopes

    International Nuclear Information System (INIS)

    Wouters, J.M.

    1982-02-01

    An extension of the experimentally known nuclidic mass surface to nuclei far from the region of beta-stability is of fundamental interest in providing a better determination of the input parameters for the various nuclear mass formulae, allowing a more accurate prediction of the ultimate limits of nuclear stability. In addition, a study of the shape of the mass surface in the vicinity of the doubly-closed nuclide 100 Sn provides initial information on the behavior of the shell closure to be expected when Z = N = 50. Experiments measuring the decay energies of 103 105 In by β-endpoint measurements are described with special attention focused on the development of a plastic scintillator β-telescope coupled to the on-line mass separator RAMA (Recoil Atom Mass Analyzer). An attempt to measure the β-endpoint energy of 102 In is also briefly described. The experimentally determined decay energies and derived masses for 103 105 In are compared with the predictions of different mass models to identify which models are more successful in this region. Furthermore, the inclusion in these comparisons of the available data on the neutron-rich indium nuclei permits a systematic study of their ground state mass behavior as a function of the neutron number between the shell closures at N = 50 and N = 82. These analyses indicate that the binding energy of 103 In is 1 MeV larger than predicted by the majority of the mass models. An examination of the Q/sub EC/ surface and the single- and two-neutron separation energies in the vicinity of 103 105 In is also performed to investigate further the deviation and other possible systematic variations in the mass surface in a model-independent way

  13. Magnetic isotope effect and theory of atomic orbital hybridization to predict a mechanism of chemical exchange reactions.

    Science.gov (United States)

    Epov, Vladimir N

    2011-08-07

    A novel approach is suggested to investigate the mechanisms of chemical complexation reactions based on the results of Fujii with co-workers; they have experimentally observed that several metals and metalloids demonstrate mass-independent isotope fractionation during the reactions with the DC18C6 crown ether using solvent-solvent extraction. In this manuscript, the isotope fractionation caused by the magnetic isotope effect is used to understand the mechanisms of chemical exchange reactions. Due to the rule that reactions are allowed for certain electron spin states, and forbidden for others, magnetic isotopes show chemical anomalies during these reactions. Mass-independent fractionation is suggested to take place due to the hyperfine interaction of the nuclear spin with the electron spin of the intermediate product. Moreover, the sign of the mass-independent fractionation is found to be dependent on the element and its species, which is also explained by the magnetic isotope effect. For example, highly negative mass-independent isotope fractionation of magnetic isotopes was observed for reactions of DC18C6 with SnCl(2) species and with several Ru(III) chloro-species, and highly positive for reactions of this ether with TeCl(6)(2-), and with several Cd(II) and Pd(II) species. The atomic radius of an element is also a critical parameter for the reaction with crown ether, particularly the element ions with [Kr]4d(n)5s(m) electron shell fits the best with the DC18C6 crown ring. It is demonstrated that the magnetic isotope effect in combination with the theory of orbital hybridization can help to understand the mechanism of complexation reactions. The suggested approach is also applied to explain previously published mass-independent fractionation of Hg isotopes in other types of chemical exchange reactions. This journal is © the Owner Societies 2011

  14. Growth and photovoltaic performance of SnS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Deepa, K.G., E-mail: deepachaithanya@gmail.com [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore (India); Nagaraju, J. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore (India)

    2012-08-01

    Highlights: Black-Right-Pointing-Pointer Orthorhombic SnS quantum dots are synthesized by chemical method. Black-Right-Pointing-Pointer HOMO-LUMO level alignments confirmed the electron transport from SnS to TiO{sub 2}. Black-Right-Pointing-Pointer Cell characteristics are analyzed with different size quantum dots. Black-Right-Pointing-Pointer FF increased drastically from 15 to 51% on adding a buffer layer to the structure. Black-Right-Pointing-Pointer The SnS QDSSC showed highest V{sub oc} of 504 mV and 2.3 mA/cm{sup 2}. - Abstract: Tin sulphide (SnS) quantum dots of size ranging from 2.4 to 14.4 nm are prepared by chemical precipitation method in aqueous media. Growth of the SnS particles is monitored by controlling the deposition time. Both XRD and SAED patterns confirm that the particles possess orthorhombic structure. The uncapped SnS particles showed secondary phases like Sn{sub 2}S{sub 3} and SnS{sub 2} which is visible in the SAED pattern. From the electrochemical characterization, HOMO-LUMO levels of both TiO{sub 2} and SnS are determined and the band alignment is found to be favorable for electron transfer from SnS to TiO{sub 2}. Moreover, the HOMO-LUMO levels varied for different particle sizes. Solar cell is fabricated by sensitizing porous TiO{sub 2} thin film with SnS QDs. Cell structure is characterized with and without buffer layer between FTO and TiO{sub 2}. Without the buffer layer, cell showed an open circuit voltage (V{sub oc}) of 504 mV and short circuit current density (J{sub sc}) of 2.3 mA/cm{sup 2} under AM1.5 condition. The low fill factor of this structure (15%) is seen to be increased drastically to 51%, on the incorporation of the buffer layer. The cell characteristics are analyzed using two different size quantum dots.

  15. Comparison between OPD-scan results and contrast sensitivity of three intraocular lenses: spheric AcrySof SN60AT, aspheric AcrySof SN60WF and multifocal AcrySof Restor lens Estudo comparativo da análise de frente de onda e sensibilidade ao contraste entre as lentes intra-oculares multifocal AcrySof Restor SN60D3, monofocal AcrySof SN60WF asférica e a monofocal SN60AT esférica

    Directory of Open Access Journals (Sweden)

    Celso Takashi Nakano

    2009-08-01

    Full Text Available Purpose: Compare the OPD-scan results and the contrast sensitivity in patients who had implantation of the AcrySof SN60D3 multifocal IOL, the AcrySof SA60AT spheric monofocal IOL and the AcrySof SN60AT aspheric monofocal IOL. Methods: Thirty-two eyes received the multifocal IOL, 32 eyes received the spheric monofocal IOL and 32 eyes received the aspheric monofocal IOL. They were closely paired in age, sex, pre-operative wavefront analysis and contrast sensitivity. All patients was tested with the OPD-scan aberrometer, ETDRS chart at 100% and 9% contrasts and contrast sensitivity. Results: Statistically significant differences were detected more total aberration in SN60AT group (KW = 9.42; p=0.009 when compared to SN60D3 group (p=0.016 and SN60WF group (p=0.0047. The SN60AT group (KW = 16.20; p=0.0003 showed with high spherical aberration values compared to the SN60WF (p=0.00046 and SN60D3 (p=0.0014 group. No significant differences were found between groups in far-distance VA measured using ETDRS at 100% and 9% contrast. The SN60D3 group compared to SN60AT group (p=0.016 had low contrast sensitivity (log units with statistical difference in 6.0 cpd (KW = 7.84; p=0.0199, but no statistical difference between SN60WF and SN60AT group (p=0.91 and SN60WF and SN60D3 group (p=0.051. The SN60D3 group had low contrast sensitivity performed under mesopic conditions (KW = 10.79; p=0,0045 in 6cpd spatial frequency compared to the SN60AT group (p=0.011 and to the SN60WF group (p=0.007 with statistical significant differences. Conclusion: In all analyzed parameters of OPD-scan aberrometry the aspheric and the multifocal IOLs provided less total and spherical aberrations than spheric IOLs. All IOLs provided an excellent high and low contrasts vision, the multifocal IOL was as good as the spheric and aspheric monofocal IOLs.Objetivo: Comparar a sensibilidade ao contraste e análise de "wavefront" com OPD-scan em pacientes submetidos a cirurgia de facoemulsifica

  16. Premaximum observations of the type Ia SN 1990N

    International Nuclear Information System (INIS)

    Leibundgut, B.; Kirshner, R.P.; Filippenko, A.V.; Shields, J.C.; Foltz, C.B.; Phillips, M.M.; Sonneborn, G.

    1991-01-01

    Spectroscopic and photometric observations of SN 1990N were obtained at ultraviolet and optical wavelengths, beginning 14 days before maximum light. The early observations reveal important differences from spectra of SN Ia's around maximum light. Photometry and spectroscopy obtained after maximum show that SN 1990N is a typical SN Ia and that most of the observed differences are due to the early epoch of the observations. The most significant characteristics are (1) the high velocities of Ca and Si up to 22,000 km/s; (2) the presence of Co and Fe 2 weeks before maximum; and (3) the more rapid increase in the UV flux compared to the optical. The most popular models for white dwarf deflagration that have provided the standard interpretation for SN Ia's at maximum light do not reproduce the high velocities of Ca II and Si II lines observed in SN 1990N. 37 refs

  17. On possibility of superconductivity in SnSb: A first principle study

    Energy Technology Data Exchange (ETDEWEB)

    Dabhi, Shweta D. [Department of Physics, M. K. Bhavnagar University, Bhavnagar 364001 (India); Shrivastava, Deepika [Department of Physics, Barkatullah University, Bhopal 462026 (India); Jha, Prafulla K., E-mail: prafullaj@yahoo.com [Department of Physics, Faculty of Science, The M. S. University of Baroda, Vadodara 390002 (India); Sanyal, Sankar P. [Department of Physics, Barkatullah University, Bhopal 462026 (India)

    2016-09-15

    Highlights: • Superconducting property of SnSb is predicted by ab-initio calculations. • Electronic properties of SnSb in RS phase shows metallic behaviour similar to SnAs. • Phonon dispersion confirms the dynamical stability of SnSb in RS phase. • Superconducting transition temperature is 3.1 K, slightly lower than that of SnAs. • Calculated thermodynamic properties are also reported. - Abstract: The electronic, phonon structure and superconducting properties of tin antimonide (SnSb) in rock-salt (RS) structure are calculated using first-principles density functional theory. The electronic band structure and density of states show metallic behavior. The phonon frequencies are positive throughout the Brillouin zone in rock-salt structure indicating its stability in that phase. Superconductivity of SnSb in RS phase is discussed in detail by calculating phonon linewidths, Eliashberg spectral function, electron-phonon coupling constant and superconducting transition temperature. SnSb is found to have a slightly lower T{sub C} (3.1 K), as compared to SnAs.

  18. Parts per billion-level detection of benzene using SnO2/graphene nanocomposite composed of sub-6 nm SnO2 nanoparticles

    International Nuclear Information System (INIS)

    Meng Fanli; Li Huihua; Kong Lingtao; Liu Jinyun; Jin Zhen; Li Wei; Jia Yong; Liu Jinhuai; Huang Xingjiu

    2012-01-01

    Graphical abstract: SnO 2 /graphene nanocomposite composed of 4–5 nm SnO 2 nanoparticles was synthesized by one-step wet chemical method and the form mechanism of the nanocomposite is clearly interpreted. The detection limit of the nanocomposite was as low as 5 ppb to toxic benzene. Highlights: ► We synthesized SnO 2 /graphene nanocomposite using a simple one-step wet chemical method. ► The nanocomposite composed of 4–5 nm SnO 2 nanoparticles. ► Toxic benzene was detected by such kind of nanocomposite. ► The detection limit to toxic benzene was as low as 5 ppb. - Abstract: In the present work, the SnO 2 /graphene nanocomposite composed of 4–5 nm SnO 2 nanoparticles was synthesized using a simple wet chemical method for ppb-level detection of benzene. The formation mechanism of the nanocomposite was investigated systematically by means of simultaneous thermogravimetry analysis, X-ray diffraction, and X-ray photoelectron spectroscopy cooperated with transmission electron microscopy observations. The SnO 2 /graphene nanocomposite showed a very attractive improved sensitivity to toxic volatile organic compounds, especially to benzene, compared to a traditional SnO 2 . The responses of the nanocomposite to benzene were a little higher than those to ethanol and the detection limit reached 5 ppb to benzene which is, to our best knowledge, far lower than those reported previously.

  19. Phase transitions in thin films of Sn-Sb-Se system

    International Nuclear Information System (INIS)

    Samsudi Sakrani; Abdalla Belal Adam; Yussof Wahab

    1998-01-01

    The preparation and formation of covalent ternary Sn-Sb-Se system were investigated. A solid state reaction technique was employed whereby the evaporated multilayers of Sn/Se/Sb/Sn reacted chemically at a fixed temperature of 240 o C and were allowed to a room temperature slow-cooling. X-ray diffraction analysis showed that phase changes occurred in the system, with indication of amorphization for the predicted Sn 9 .3Sb 8 .1Se 4 4.9 and Sn 1 3.2Sb 4 3.4Se 4 3.4 compositions. These enabled the preliminary topological phase transitions of Sn-Sb-Se system according to the Gibb's triangle in which the areas of crystalline-amorphous were located. (Author)

  20. HET LRS2 Observations of Halpha in Old Hydrogen-deficient Supernovae

    Science.gov (United States)

    Wheeler, J. Craig Craig; Pooley, David A.; Vinko, Jozsef; Szalai, Tamas; Marion, Howie H.; Sand, David J.; McQueen, Phillip; Silverman, Jeffrey M.

    2017-06-01

    For 3 years, we have been using narrow-band filters with the DIAFI imager on the HJS 2.7 m telescope to search for evidence that hydrogen-deficient supernovae undergo delayed collision with previously ejected circumstellar material and associated excitation of Halpha (see abstract by Pooley et al.). A powerful method to determine whether detected Halpha flux is from an HII region or a supernova is to obtain spectra; broad lines (> 1000 km/s) will be a certain indicator of a supernova. We have observed about 20 events that ranged in age from about 1000 days to nearly 80 years for which we have detected Halpha in the vicinity of the supernova. So far, only SN 2014C showed the broad H that is concrete evidence of ongoing circumstellar interaction. One interesting aspect revealed by the spectra is that we often pick up the two [N II] lines that typically accompany H in H II regions. Our spectra of SN 2008ha did not show these [N II] lines. The absence of the [N II] lines might be a clue to circumstellar interaction in conditions where the shock had slowed to a point where the H is not detectably broadened.