Simultaneous solution to the 6Li and 7Li big bang nucleosynthesis problems from a long-lived negatively charged leptonic particle

International Nuclear Information System (INIS)

Kusakabe, Motohiko; Kajino, Toshitaka; Boyd, Richard N.; Yoshida, Takashi; Mathews, Grant J.

2007-01-01

The 6 Li abundance observed in metal-poor halo stars exhibits a plateau similar to that for 7 Li suggesting a primordial origin. However, the observed abundance of 6 Li is a factor of 10 3 larger and that of 7 Li is a factor of 3 lower than the abundances predicted in the standard big bang when the baryon-to-photon ratio is fixed by Wilkinson microwave anisotropy probe. Here we show that both of these abundance anomalies can be explained by the existence of a long-lived massive, negatively charged leptonic particle during nucleosynthesis. Such particles would capture onto the synthesized nuclei thereby reducing the reaction Coulomb barriers and opening new transfer reaction possibilities, and catalyzing a second round of big bang nucleosynthesis. This novel solution to both of the Li problems can be achieved with or without the additional effects of stellar destruction

The reaction d(α,γ)6Li at low energies and the primordial nucleosynthesis of 6Li

International Nuclear Information System (INIS)

Cecil, F.E.; Yan, J.; Galovich, C.S.

1996-01-01

We have searched for the reaction d(α,γ) 6 Li at an α-d center-of-mass energy of 53 keV. An upper limit on the reaction S factor is 2.0x10 -7 MeVb at the 90% confidence level, corresponding to a limit on the synthesis of 6 Li from a standard big bang of 0.9% of the present abundance for a total baryon-to-photon ratio 2.86 10 6 Li-to- 7 Li isotopic abundance ratio immediately after a standard big bang is constrained to be less than 0.85%, considerably less than a recent measurement of this ratio in a metal-poor, Population II halo star. copyright 1996 The American Physical Society

Reaction channels of 6,7Li+28Si at near-barrier energies

International Nuclear Information System (INIS)

Pakou, A; Rusek, K; Nicolis, N G; Alamanos, N; Doukelis, G; Gillibert, A; Kalyva, G; Kokkoris, M; Lagoyannis, A; Musumarra, A; Papachristodoulou, C; Perdikakis, G; Pierroutsakou, D; Pollacco, E C; Spyrou, A; Zarkadas, Ch

2005-01-01

The production of α-particles in the reactions 6,7 Li+ 28 Si was studied as a means to disentangle the various reaction channels at near-barrier energies. The competition between compound and direct reactions was determined by using the shape of angular distributions and statistical model calculations. DWBA calculations were also performed to probe the various direct channels. It was found that, approaching barrier, transfer channels are the most dominant for both reactions. For 7 Li+ 28 Si d-transfer is one of the contributing channels without excluding t-transfer, while for 6 Li+ 28 Si, n-transfer and p-transfer have substantial contribution but without excluding d-transfer

Investigation of the antiprotonic X-ray spectrum of the lithium isotopes 6Li and 7Li

International Nuclear Information System (INIS)

Guigas, R.

1981-09-01

Antiprotons of the low-energy separated anti p-beam K 23 at CERN in Geneva have been stopped in thin (0.6 g/cm 2 ) targets of the Lithium isotopes 6 Li and 7 Li. The characteristic X-rays of the formed antiprotonic atoms were measured with four identical high-resolution Si (Li) detectors. Three lines of the N- series, four lines of the M-series and the 3d-2p transition of the Balmer series were observed. The measured relative intensities of the M- and N-series transitions are well described by the simple cascade model of Eisenberg and Kessler. The 3d-2p transition is considerably influenced by the strong interaction between antiproton and nucleus and thus drastically reduced in intensity. The analysis of this transition yields the shift and width of the 2p level, whereas the width of the 3d level is deduced from intensity considerations. (orig./HSI)

Trojan horse particle invariance studied with the 6Li(d,α)4He and 7Li(p,α)4He reactions

International Nuclear Information System (INIS)

Pizzone, R. G.; Spitaleri, C.; Lamia, L.; Cherubini, S.; La Cognata, M.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Bertulani, C.; Mukhamedzhanov, A.; Blokhintsev, L.; Burjan, V.; Hons, Z.; Kroha, V.; Mrazek, J.; Piskor, S.; Kiss, G. G.; Li, C.; Tumino, A.

2011-01-01

The Trojan horse nucleus invariance for the binary reaction cross section extracted from the Trojan horse reaction was tested using the quasifree 3 He( 6 Li,αα)H and 3 He( 7 Li,αα) 2 H reactions. The cross sections for the 6 Li(d,α) 4 He and 7 Li(p,α) 4 He binary processes were extracted in the framework of the plane wave approximation. They are compared with direct behaviors as well as with cross sections extracted from previous indirect investigations of the same binary reactions using deuteron as the Trojan horse nucleus instead of 3 He. The very good agreement confirms the applicability of the plane wave approximation which suggests the independence of the binary indirect cross section on the chosen Trojan horse nucleus, at least for the investigated cases.

Exploring incomplete fusion fraction in 6,7Li induced nuclear reactions

Science.gov (United States)

Parkar, V. V.; Jha, V.; Kailas, S.

2017-11-01

We have included breakup effects explicitly to simultaneously calculate the measured cross-sections of the complete fusion, incomplete fusion, and total fusion for 6,7Li projectiles on various targets using the Continuum Discretized Coupled Channels method. The breakup absorption cross-sections obtained with different choices of short range imaginary potentials are utilized to evaluate the individual α-capture and d/t-capture cross-sections and compare with the measured data. It is interesting to note, while in case of 7Li projectile the cross-sections for triton-ICF/triton-capture is far more dominant than α-ICF/α-capture at all energies, similar behavior is not observed in case of 6Li projectile for the deuteron-ICF/deuteron-capture and α-ICF/α-capture. Both these observations are also corroborated by the experimental data for all the systems studied.

Exploring incomplete fusion fraction in 6,7Li induced nuclear reactions

Directory of Open Access Journals (Sweden)

Parkar V. V.

2017-01-01

Full Text Available We have included breakup effects explicitly to simultaneously calculate the measured cross-sections of the complete fusion, incomplete fusion, and total fusion for 6,7Li projectiles on various targets using the Continuum Discretized Coupled Channels method. The breakup absorption cross-sections obtained with different choices of short range imaginary potentials are utilized to evaluate the individual α-capture and d/t-capture cross-sections and compare with the measured data. It is interesting to note, while in case of 7Li projectile the cross-sections for triton-ICF/triton-capture is far more dominant than α-ICF/α-capture at all energies, similar behavior is not observed in case of 6Li projectile for the deuteron-ICF/deuteron-capture and α-ICF/α-capture. Both these observations are also corroborated by the experimental data for all the systems studied.

Parsec-scale Variations in the "7Li i/"6Li i Isotope Ratio Toward IC 348 and the Perseus OB 2 Association

International Nuclear Information System (INIS)

Knauth, D. C.; Taylor, C. J.; Federman, S. R.; Ritchey, A. M.; Lambert, D. L.

2017-01-01

Measurements of the lithium isotopic ratio in the diffuse interstellar medium from high-resolution spectra of the Li i λ 6708 resonance doublet have now been reported for a number of lines of sight. The majority of the results for the "7Li/"6Li ratio are similar to the solar system ratio of 12.2, but the line of sight toward o Per, a star near the star-forming region IC 348, gave a ratio of about two, the expected value for gas exposed to spallation and fusion reactions driven by cosmic rays. To examine the association of IC 348 with cosmic rays more closely, we measured the lithium isotopic ratio for lines of sight to three stars within a few parsecs of o Per. One star, HD 281159, has "7Li/"6Li ≃ 2 confirming production by cosmic rays. The lithium isotopic ratio toward o Per and HD 281159 together with published analyses of the chemistry of interstellar diatomic molecules suggest that the superbubble surrounding IC 348 is the source of the cosmic rays.

Quaternary system LiF-LiCl-LiVO3-Li2MoO4

International Nuclear Information System (INIS)

Anipchenko, B.V.; Garkushin, I.K.

2000-01-01

Interactions in the LiF-LiCl-LiVO 3 -Li 2 MoO 4 system are studied by differential thermal analysis. Rate of heating/cooling of the samples comprised 15 Grad/min, mass of sample composed 0.2 g. The system was investigated in the 300-650 Deg C range. X-ray diffraction method was used for determination of purity of the reagents. Composition and temperature of quaternary component eutectics are determined: 16.5 mol. % of LiF, 47.0 mol. % of LiCl, 28.8 mol. % of LiVO 3 , 7.6 mol. % of Li 2 MoO 4 ; 387 Deg C. Mean value of melting enthalpy of quaternary eutectics mixture in the LiF-LiCl-LiVO 3 -Li 2 MoO 4 system on the results of the tests was in the range of 222 kJ/kg [ru

Ab initio investigations of the electronic structures and chemical bonding in LiCo{sub 6}P{sub 4} and Li{sub 2}Co{sub 12}P{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Matar, Samir F. [CNRS, ICMCB, UPR 9048, F‐33600 Pessac (France); Université de Bordeaux, ICMCB, UPR 9048, F‐33600 Pessac (France); Al-Alam, Adel; Ouaini, Naïm [Université Saint-Esprit de Kaslik (USEK), Groupe OCM (Optimization et Caractérisation des Matériaux), CSR-USEK, CNRS-L, Jounieh (Lebanon); Pöttgen, Rainer, E-mail: pottgen@uni-muenster.de [Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, D-48149 Münster (Germany)

2013-06-15

The electronic structures of the metal-rich phosphides LiCo{sub 6}P{sub 4} and Li{sub 2}Co{sub 12}P{sub 7} were studied by DFT calculations. Both phosphides consist of three-dimensional [Co{sub 6}P{sub 4}] and [Co{sub 12}P{sub 7}] polyanionic networks which leave hexagonal channels for the lithium atoms. COOP data show strong Co–P and Co–Co bonding within the polyanions. The lithium atoms have trigonal prismatic phosphorus coordination. Total energy calculations indicate stability upon de-lithiation towards the Co{sub 6}P{sub 4} and Co{sub 12}P{sub 7} substructures - Graphical abstract: The cobalt–phosphorus networks in LiCo{sub 6}P{sub 4} and Li{sub 2}Co{sub 12}P{sub 7}. - Highlights: • Chemical bonding resolved in the metal-rich phosphides LiCo{sub 6}P{sub 4} and Li{sub 2}Co{sub 12}P{sub 7}. • Strong covalent Co–P bonding character in the [Co{sub 6}P{sub 4}] and [Co{sub 12}P{sub 7}] substructures. • Total energy calculations indicate stability of the de-lithiated substructures.

Fusion cross sections for 6,7Li + 24Mg at energies around the barrier

International Nuclear Information System (INIS)

Ray, Maitreyi; Pradhan, M.K.; Kshetri, R.; Mukherjee, A.; Saha Sarkar, M.; Biswas, M.; Roy, S.; Basu, P.; Majumdar, H.; Dasmahapatra, B.; Sinha, M.; Palit, R.; Mazumdar, I.; Joshi, P.K.; Jain, H.C.

2006-01-01

The 6,7 Li + 24 Mg reactions in the energy interval E lab = 11-32 MeV using 6,7 Li beams have been investigated from the 14 UD BARC-TIFR Pelletron accelerator at TIFR, Mumbai. The γ-ray cross sections were measured using a Compton suppressed clover detector, placed at 55 deg with respect to the beam direction

Response distributions of 6LiF and 7LiF thermoluminescence dosimeters in lithium blanket assemblies

International Nuclear Information System (INIS)

Maekawa, Hiroshi; Kusano, Jyo-ichi; Seki, Yasushi

1976-11-01

Measurement of the radiation-heating rate distribution in the fusion blanket is as important as measurement of the fission-rate distribution in a fission reactor. To obtain the information of radiation heating, the response (integral glow value) distributions in pseudo-spherical lithium assemblies with and without a graphite reflector were measured with 6 LiF and 7 LiF TLD's. The measured responses are normalized to values per source neutron. Experimental error is about 35%, and the error in positions of TLD's is about +- 3 mm. The experimental results are compared with those of calculation using RADHEAT code system and ENDF/B-III data file. (auth.)

Li+ transport properties of W substituted Li7La3Zr2O12 cubic lithium garnets

Directory of Open Access Journals (Sweden)

L. Dhivya

2013-08-01

Full Text Available Lithium garnet Li7La3Zr2O12 (LLZ sintered at 1230 °C has received considerable importance in recent times as result of its high total (bulk + grain boundary ionic conductivity of 5 × 10−4 S cm−1 at room temperature. In this work we report Li+ transport process of Li7−2xLa3Zr2−xWxO12 (x = 0.3, 0.5 cubic lithium garnets. Among the investigated compounds, Li6.4La3Zr1.7W0.3O12 sintered relatively at lower temperature 1100 °C exhibits highest room temperature (30 °C total (bulk + grain boundary ionic conductivity of 7.89 × 10−4 S cm−1. The temperature dependencies of the bulk conductivity and relaxation frequency in the bulk are governed by the same activation energy. Scaling the conductivity spectra for both Li6.4La3Zr1.7W0.3O12 and Li6La3Zr1.5W0.5O12 sample at different temperatures merges on a single curve, which implies that the relaxation dynamics of charge carriers is independent of temperature. The shape of the imaginary part of the modulus spectra suggests that the relaxation processes are non-Debye in nature. The present studies supports the prediction of optimum Li+ concentration required for the highest room temperature Li+ conductivity in LixLa3M2O12 is around x = 6.4 ± 0.1.

Fabrication and characterization of 6Li-enriched Li2TiO3 pebbles for a high Li-burnup irradiation test

International Nuclear Information System (INIS)

Tsuchiya, Kunihiko; Kawamura, Hiroshi

2006-10-01

Lithium titanate (Li 2 TiO 3 ) pebbles are considered to be a candidate material of tritium breeders for fusion reactor from viewpoints of easy tritium release at low temperatures (about 300degC) and chemical stability. In the present study, trial fabrication tests of 6 Li-enriched Li 2 TiO 3 pebbles of 1mm in diameter were carried out by a wet process with a dehydration reaction, and characteristics of the 6 Li-enriched Li 2 TiO 3 pebbles were evaluated for preparation of a high Li-burnup test in a testing reactor. Powder of 96at% 6 Li-enriched Li 2 TiO 3 was prepared by a solid state reaction, and two kinds of 6 Li-enriched Li 2 TiO 3 pebbles, namely un-doped and TiO 2 -doped Li 2 TiO 3 pebbles, were fabricated by the wet process. Based on results of the pebble fabrication tests, two kinds of 6 Li-enriched Li 2 TiO 3 pebbles were successfully fabricated with target values (density: 80-85%T.D., grain size: 2 TiO 3 pebbles was a satisfying value of about 1.05. Contact strength of these pebbles was about 6300MPa, which was almost the same as that of the Li 2 TiO 3 pebbles with natural Li. (author)

Measurement of the 2H(7Be, 6Li)3He reaction rate and its contribution to the primordial lithium abundance

Science.gov (United States)

Li, Er-Tao; Li, Zhi-Hong; Yan, Sheng-Quan; Su, Jun; Guo, Bing; Li, Yun-Ju; Wang, You-Bao; Lian, Gang; Zeng, Sheng; Chen, Si-Zhe; Ma, Shao-Bo; Li, Xiang-Qing; He, Cao; Sun, Hui-Bin; Liu, Wei-Ping

2018-04-01

In the standard Big Bang nucleosynthesis (SBBN) model, the lithium puzzle has attracted intense interest over the past few decades, but still has not been solved. Conventionally, the approach is to include more reactions flowing into or out of lithium, and study the potential effects of those reactions which were not previously considered. 7Be(d, 3He)6Li is a reaction that not only produces 6Li but also destroys 7Be, which decays to 7Li, thereby affecting 7Li indirectly. Therefore, this reaction could alleviate the lithium discrepancy if its reaction rate is sufficiently high. However, there is not much information available about the 7Be(d, 3He)6Li reaction rate. In this work, the angular distributions of the 7Be(d, 3He)6Li reaction are measured at the center of mass energies E cm = 4.0 MeV and 6.7 MeV with secondary 7Be beams for the first time. The excitation function of the 7Be(d, 3He)6Li reaction is first calculated with the computer code TALYS and then normalized to the experimental data, then its reaction rate is deduced. A SBBN network calculation is performed to investigate its influence on the 6Li and 7Li abundances. The results show that the 7Be(d, 3He)6Li reaction has a minimal effect on 6Li and 7Li because of its small reaction rate. Therefore, the 7Be(d, 3He)6Li reaction is ruled out by this experiment as a means of alleviating the lithium discrepancy. Supported by National Natural Science Foundation of China (11375269, 11505117, 11490560, 11475264, 11321064), Natural Science Foundation of Guangdong Province (2015A030310012), 973 program of China (2013CB834406) and National key Research and Development Province (2016YFA0400502)

Low-energy cross sections of the BBN reaction d({alpha},{gamma}){sup 6}Li by Coulomb dissociation of {sup 6}Li

Energy Technology Data Exchange (ETDEWEB)

Heil, Michael; Suemmerer, Klaus [GSI Darmstadt (Germany); Hammache, Fairouz [IPN Orsay (France); Galaviz, Daniel [TU Darmstadt (Germany); Typel, Stefan [GANIL Caen (France)

2008-07-01

The primordial abundances of D, ({sup 3}He), {sup 4}He, and {sup 7}Li can be used to infer the baryon density of the Universe based on the framework of Big-Bang Nucleosynthesis (BBN). By precision measurements of the cosmic microwave background (CMB) an independent method became available recently. This lead to a renewed interest for BBN. Together with the recent observation of {sup 6}Li in old stars and the problems to reconcile calculated primordial {sup 7}Li abundances with those predicted on the basis of CMB results, the production of both, {sup 6}Li and {sup 7}Li in BBN has been reinvestigated. One important ingredient is the low-energy S-factor of the d-alpha radiative-capture reaction. Up to now, the only available experimental result by Kiener et al. (1991) introduced an uncertainty of about a factor of 20 in the {sup 6}Li yield. We have therefore reinvestigated the d-alpha reaction with the help of Coulomb dissociation (CD) of {sup 6}Li at 150 MeV/nucleon at GSI. CD is the only practical way to study the low-energy S-factor (which involves l=2 multipolarity) due to the large number of E2 photons contained in the equivalent-photon flux. Preliminary results indicate a drop of the S-factor as predicted by theory, contrary to the constant low-energy S-factor resulting from the previous study.

Li7(BH)5(+): a new thermodynamically favored star-shaped molecule.

Science.gov (United States)

Torres-Vega, Juan J; Vásquez-Espinal, Alejandro; Beltran, Maria J; Ruiz, Lina; Islas, Rafael; Tiznado, William

2015-07-15

The potential energy surfaces (PESs) of Lin(BH)5(n-6) systems (where n = 5, 6, and 7) were explored using the gradient embedded genetic algorithm (GEGA) program, in order to find their global minima conformations. This search predicts that the lowest-energy isomers of Li6(BH)5 and Li7(BH)5(+) contain a (BH)5(6-) pentagonal fragment, which is isoelectronic and structurally analogous to the prototypical aromatic hydrocarbon anion C5H5(-). Li7(BH)5(+), along with Li7C5(+), Li7Si5(+) and Li7Ge5(+), joins a select group of clusters that adopt a seven-peak star-shape geometry, which is favored by aromaticity in the central five-membered ring, and by the preference of Li atoms for bridging positions. The theoretical analysis of chemical bonding, based on magnetic criteria, supports the notion that electronic delocalization is an important stabilization factor in all these star-shaped clusters.

Parsec-scale Variations in the {sup 7}Li i/{sup 6}Li i Isotope Ratio Toward IC 348 and the Perseus OB 2 Association

Energy Technology Data Exchange (ETDEWEB)

Knauth, D. C. [Woodlawn High School, 1801 Woodlawn Drive, Baltimore, MD 21207 (United States); Taylor, C. J.; Federman, S. R. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Ritchey, A. M. [Department of Astronomy, University of Washington, Seattle, WA, 98195 (United States); Lambert, D. L., E-mail: knauth_dc2@hotmail.com, E-mail: steven.federman@utoledo.edu, E-mail: cjtaylor@astro.umd.edu, E-mail: aritchey@astro.washington.edu, E-mail: dll@astro.as.utexas.edu [Department of Astronomy, University of Texas, Austin, TX 78712 (United States)

2017-01-20

Measurements of the lithium isotopic ratio in the diffuse interstellar medium from high-resolution spectra of the Li i λ 6708 resonance doublet have now been reported for a number of lines of sight. The majority of the results for the {sup 7}Li/{sup 6}Li ratio are similar to the solar system ratio of 12.2, but the line of sight toward o Per, a star near the star-forming region IC 348, gave a ratio of about two, the expected value for gas exposed to spallation and fusion reactions driven by cosmic rays. To examine the association of IC 348 with cosmic rays more closely, we measured the lithium isotopic ratio for lines of sight to three stars within a few parsecs of o Per. One star, HD 281159, has {sup 7}Li/{sup 6}Li ≃ 2 confirming production by cosmic rays. The lithium isotopic ratio toward o Per and HD 281159 together with published analyses of the chemistry of interstellar diatomic molecules suggest that the superbubble surrounding IC 348 is the source of the cosmic rays.

Test of level density models from reactions of Li6 on Fe58 and Li7 on Fe57

Science.gov (United States)

Oginni, B. M.; Grimes, S. M.; Voinov, A. V.; Adekola, A. S.; Brune, C. R.; Carter, D. E.; Heinen, Z.; Jacobs, D.; Massey, T. N.; O'Donnell, J. E.; Schiller, A.

2009-09-01

The reactions of Li6 on Fe58 and Li7 on Fe57 have been studied at 15 MeV beam energy. These two reactions produce the same compound nucleus, Cu64. The charged particle spectra were measured at backward angles. The data obtained have been compared with Hauser-Feshbach model calculations. The level density parameters of Ni63 and Co60 have been obtained from the particle evaporation spectra. We also find contributions from the break up of the lithium projectiles to the low energy region of the α spectra.

Parsec-scale Variations in the 7Li I/6Li I Isotope Ratio Toward IC 348 and the Perseus OB 2 Association

Science.gov (United States)

Knauth, D. C.; Taylor, C. J.; Ritchey, A. M.; Federman, S. R.; Lambert, D. L.

2017-01-01

Measurements of the lithium isotopic ratio in the diffuse interstellar medium from high-resolution spectra of the Li I λ6708 resonance doublet have now been reported for a number of lines of sight. The majority of the results for the 7Li/6Li ratio are similar to the solar system ratio of 12.2, but the line of sight toward o Per, a star near the star-forming region IC 348, gave a ratio of about two, the expected value for gas exposed to spallation and fusion reactions driven by cosmic rays. To examine the association of IC 348 with cosmic rays more closely, we measured the lithium isotopic ratio for lines of sight to three stars within a few parsecs of o Per. One star, HD 281159, has 7Li/6Li ≃ 2 confirming production by cosmic rays. The lithium isotopic ratio toward o Per and HD 281159 together with published analyses of the chemistry of interstellar diatomic molecules suggest that the superbubble surrounding IC 348 is the source of the cosmic rays. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

7Li--7Be experiment

International Nuclear Information System (INIS)

Rowley, J.K.

1978-01-01

An experiment to detect solar neutrinos by use of lithium is considered. The reaction employed is 7 Li(ν,e - ) 7 Be. The parameters of a possible experimental arrangement are described; chemical separation, backgrounds, and counting are discussed at some length. Despite the problems such an experiment still seems feasible. 5 figures, 6 tables

The optical potential for 6Li-6Li elastic scattering at 156 MeV

International Nuclear Information System (INIS)

Micek, S.; Majka, Z.; Klewe-Nebenius, H.; Rebel, H.; Gils, H.J.

1984-10-01

Elastic scattering of 6 Li from 6 Li has been studied for the beam energy of 156 MeV. The experimental differential cross section has been analysed on the basis of the optical model using various phenomenological forms. The spin-orbit interaction proves to be less significant. A semi-microscopic double-folding cluster model which generates the real part of the optical potential by an antisymmetrized d-α cluster wave function of 6 Li and α-α, d-d and d-α interactions is well able to describe the experimental data. (orig.) [de

Five-nucleon simultaneous and sequential transfer in the 12C(11B,6Li)17O and 12C(d,7Li)7Be reactions

International Nuclear Information System (INIS)

Jarczyk, L.; Kamys, B.; Kistryn, M.; Magiera, A.; Rudy, Z.; Strzal/kowski, A.; Barna, R.; DAmico, V.; De Pasquale, D.; Italiano, A.; Licandro, M.

1996-01-01

Measurements of the angular distributions of the 12 C( 11 B, 6 Li) 17 O reaction were performed at three energies of a 11 B beam: 28, 35, and 40 MeV. The results were analyzed in the frame of the exact finite range distorted wave Born approximation of the first and the second order assuming the simultaneous and sequential transfer of the neutron and the α particle. Such an analysis was also performed for previously measured angular distributions of the 12 C(d, 7 Li) 7 Be reaction at E lab = 78 MeV. In both reactions under investigation dominance was found of the simultaneous transfer of the α particle and the nucleon correlated to the 5 He ( 5 Li) cluster in the ground or the first excited state. copyright 1996 The American Physical Society

Systematics of the breakup probability function for {sup 6}Li and {sup 7}Li projectiles

Energy Technology Data Exchange (ETDEWEB)

Capurro, O.A., E-mail: capurro@tandar.cnea.gov.ar [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); Pacheco, A.J.; Arazi, A. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Carnelli, P.F.F. [CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650BWA San Martín, Buenos Aires (Argentina); Fernández Niello, J.O. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650BWA San Martín, Buenos Aires (Argentina); and others

2016-01-15

Experimental non-capture breakup cross sections can be used to determine the probability of projectile and ejectile fragmentation in nuclear reactions involving weakly bound nuclei. Recently, the probability of both type of dissociations has been analyzed in nuclear reactions involving {sup 9}Be projectiles onto various heavy targets at sub-barrier energies. In the present work we extend this kind of systematic analysis to the case of {sup 6}Li and {sup 7}Li projectiles with the purpose of investigating general features of projectile-like breakup probabilities for reactions induced by stable weakly bound nuclei. For that purpose we have obtained the probabilities of projectile and ejectile breakup for a large number of systems, starting from a compilation of the corresponding reported non-capture breakup cross sections. We parametrize the results in accordance with the previous studies for the case of beryllium projectiles, and we discuss their systematic behavior as a function of the projectile, the target mass and the reaction Q-value.

Mechanisms of emission of particles charged in 6Li + 6Li and 6Li + 10B reactions at low energies

International Nuclear Information System (INIS)

Quebert, Jean

1964-01-01

The lithium 6 nucleus is a projectile of interest to study nuclear reactions at low energy due to the possibility to obtain high heats of reaction, and to its structure which can play an important role in the projectile-target interaction. This research thesis focused on the study of two low-energy reactions provoked by lithium projectiles. These reactions are studied within the framework of the theoretical model of aggregates. The first part presents the experimental conditions of both reactions, reports the development and analysis of nuclear plates, and the transformation of a given type of particle histogram into a spectrum in the mass centre system. The next parts report the study of the 6 Li + 6 Li reaction (previous results, kinematic analysis, spectrum of secondary particles, theoretical analysis of results) and of the 6 Li + 10 B reaction (previous results, experimental results, study of the continuous spectrum of alpha particle, reaction mechanisms)

The "7Li(d, p)"8Li reaction in inverse kinematics at 5.44 MeV/u

International Nuclear Information System (INIS)

Pakou, A.; Aslanoglou, X.; Sgouros, O.; Soukeras, V.; Keeley, N.; Cappuzzello, F.; Acosta, L.; Agodi, C.; Calabrese, S.; Carbone, D.; Cavallaro, M.; Foti, A.; Marquinez-Duran, G.; Martel, I.; Mazzocco, M.; Strano, E.; Parascandolo, C.; Pierroutsakou, D.; Rusek, K.; Zagatto, V.A.B.

2017-01-01

New data are presented for the "7Li(d, p)"8Li stripping reaction which, together with previously reported elastic scattering data taken in the same experiment, provide a coherent set. These data, plus existing measurements of the elastic scattering and stripping at 6 MeV/u were analysed within the same coupled reaction channels scheme. Good descriptions of the stripping data to the 0.0 MeV 2"+ and 0.98 MeV 1"+ states of "8Li were obtained using a set of left angle "8Li vertical stroke "7Li + n right angle overlaps taken from the literature, provided that the elastic scattering was also well described. Multi-step reaction paths made significant contributions to the description of the larger angle data. The asymptotic normalisation coefficients are compared with previous determinations. (orig.)

Nuclear reaction rates and primordial 6Li

International Nuclear Information System (INIS)

Nollett, K.M.; Schramm, D.N.; Lemoine, M.; Schramm, D.N.; Lemoine, M.; Schramm, D.N.

1997-01-01

We examine the possibility that big-bang nucleosynthesis (BBN) may produce nontrivial amounts of 6 Li. If a primordial component of this isotope could be observed, it would provide a new fundamental test of big-bang cosmology, as well as new constraints on the baryon density of the universe. At present, however, theoretical predictions of the primordial 6 Li abundance are extremely uncertain due to difficulties in both theoretical estimates and experimental determinations of the 2 H(α,γ) 6 Li radiative capture reaction cross section. We also argue that present observational capabilities do not yet allow the detection of primeval 6 Li in very metal-poor stars of the galactic halo. However, if the critical cross section is very high in its plausible range and the baryon density is relatively low, then improvements in 6 Li detection capabilities may allow the establishment of 6 Li as another product of BBN. It is also noted that a primordial 6 Li detection could help resolve current concerns about the extragalactic D/H determination. copyright 1997 The American Physical Society

Static and dynamic moments of the 7Li nucleus

International Nuclear Information System (INIS)

Barker, F.C.; Kondo, Y.; Spear, R.H.

1989-09-01

The data of Weller et al. (1985) on the tensor analysing powers for elastic and inelastic Coulomb scattering of aligned 7 Li ions have been reanalyzed in order to obtain information on the values of the four 7 Li moments Q, B(E2)↑, τ 11 and τ 12 . It is shown that a single set of values, chosen primarily to be consistent with the value of Q measured by molecular techniques and the values of B(E2)↑ and τ 12 . required to fit unpolarized 7 Li data, and also with the theoretical constraint τ 11 ≅-[τ 12 ], gives a good fit to the aligned 7 Li data. 19 refs., 6 figs

Measurements of double-differential neutron emission cross sections of {sup 6}Li and {sup 7}Li for 18 MeV neutrons

Energy Technology Data Exchange (ETDEWEB)

Ibaraki, Masanobu; Baba, Mamoru; Matsuyama, Shigeo; Sanami, Toshiya; Win, T.; Miura, Takako; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan). Faculty of Engineering

1997-03-01

Double-differential neutron emission cross sections of {sup 6}Li and {sup 7}Li were measured for 18 MeV neutrons at Tohoku University 4.5 MV Dynamitron facility. Neutron emission spectra were obtained down to 1 MeV at 13 angles with energy resolution good enough to separate discrete levels. A care was taken to eliminate the sample-dependent background due to parasitic neutrons. Experimental results were in fair agreement with the JENDL-3.2 data and a simple model considering a three-body breakup process and discrete level excitations. (author)

Transfer of 6Li break-up fragments at 6Li projectile energies far above the coulomb barrier

International Nuclear Information System (INIS)

Neumann, B.; Buschmann, J.; Rebel, H.; Gils, H.J.; Klewe-Nebenius, H.

1979-05-01

Transfer of beam-velocity fragments has been experimentally investigated in 6 Li induced reactions on 208 Pb and 209 Bi in the energy range Esub(Li) = 60-156 MeV. The experimental techniques involve the observation of the target residues and measurements of the recoil ranges of heavy residual nuclei produced by charged particle bombardment. The determination of the recoil energy enables the discrimination of different reaction paths leading to the same residual nuclei. ( 6 Li, xn+p) excitation functions prove to be very similar to (α,(x-1)n) reactions at Esub(α) approximately 2/3 x Esub(Li). The results present experimental evidence for a particular reaction type indicated in previous experiments: Dissociation of the 6 Li projectile with capture of the beam-velocity alpha particle indicating an (α,xn) reaction ('internal break-up'). (orig.) [de

Fragmentation properties of 6Li

International Nuclear Information System (INIS)

Lovas, R.G.; Kruppa, A.T.; Beck, R.; Dickmann, F.

1987-01-01

The α+d and t+τ cluster structure of 6 Li is described in a microscopic α+d cluster model through quantities that enter into the description of cluster fragmentation processes. The states of the separate clusters α, d, t and τ are described as superpositions of Os Slater determinants belonging to different potential size parameters. To describe both the 6 Li and fragment state realistically, nucleon-nucleon forces optimized for the used model state spaces were constructed. The fragmentation properties predicted by them slightly differ from those calculated with some forces of common use provided the latter are modified so as to reproduce the α, d and 6 Li energies. (author) 61 refs.; 9 figs

Depth profiling Li in electrode materials of lithium ion battery by {sup 7}Li(p,γ){sup 8}Be and {sup 7}Li(p,α){sup 4}He nuclear reactions

Energy Technology Data Exchange (ETDEWEB)

Sunitha, Y., E-mail: sunibarc@gmail.com; Kumar, Sanjiv

2017-06-01

A proton induced γ-ray emission method based on {sup 7}Li(p,γ){sup 8}Be proton capture reaction and a nuclear reaction analysis method involving {sup 7}Li(p,α){sup 4}He reaction are described for depth profiling Li in the electrode materials, graphite and lithium cobalt oxide for example, of a Li-ion battery. Depth profiling by {sup 7}Li(p,γ){sup 8}Be reaction is accomplished by the resonance at 441 keV and involves the measurement of 14.6 and 17.6 MeV γ-rays, characteristic of the reaction, by a NaI(Tl) detector. The method has a detection sensitivity of ∼0.2 at% and enables profiling up to a depth ≥20 µm with a resolution of ≥150 nm. The profiling to a fairly large depth is facilitated by the absence of any other resonance up to 1800 keV proton energy. The reaction has substantial off-resonance cross-sections. A procedure is outlined for evaluating the off-resonance yields. Interferences from fluorine and aluminium are major limitation of this depth profiling methodology. The depth profile measurement by {sup 7}Li(p,α){sup 4}He reaction, on the other hand, utilises 2–3 MeV protons and entails the detection of α-particles at 90° or 150° angles. The reaction exhibits inverse kinematics at 150°. This method, too, suffers interference from fluorine due to the simultaneous occurrence of {sup 19}F(p,α){sup 16}O reaction. Kinematical considerations show that the interference is minimal at 90° and thus is the recommended angle of detection. The method is endowed with a detection sensitivity of ∼0.1 at%, a depth resolution of ∼100 nm and a probing depth of about 30 µm in the absence and 5–8 µm in the presence of fluorine in the material. Both methods yielded comparable depth profiles of Li in the cathode (lithium cobalt oxide) and the anode (graphite) of a Li-ion battery.

7Li(d,p)8Li transfer reaction in the NCSM/RGM approach

Science.gov (United States)

Raimondi, F.; Hupin, G.; Navrátil, P.; Quaglioni, S.

2018-03-01

Recently, we applied an ab initio method, the no-core shell model combined with the resonating group method, to the transfer reactions with light p-shell nuclei as targets and deuteron as the projectile. In particular, we studied the elastic scattering of deuterium on 7Li and the 7Li(d,p)8Li transfer reaction starting from a realistic two-nucleon interaction. In this contribution, we review of our main results on the 7Li(d,p)8Li transfer reaction, and we extend the study of the relevant reaction channels, by showing the dominant resonant phase shifts of the scattering matrix. We assess also the impact of the polarization effects of the deuteron below the breakup on the positive-parity resonant states in the reaction. For this purpose, we perform an analysis of the convergence trend of the phase and eigenphase shifts, with respect to the number of deuteron pseudostates included in the model space.

Puzzle of the 6Li Quadrupole Moment: Steps toward Solving It

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Kukulin, V.I.; Pomerantsev, V.N.

2005-01-01

The problem of the origin of the quadrupole deformation in the 6 Li ground state is investigated with allowance for the three-deuteron component of the 6 Li wave function. Two long-standing puzzles related to the tensor interaction in the 6 Li nucleus are known: that of an anomalous smallness of the 6 Li quadrupole moment (being negative, it is smaller in magnitude than the 7 Li quadrupole moment by a factor of 5) and that of an anomalous behavior of the tensor analyzing power T 2q in the scattering of polarized 6 Li nuclei on various targets. It is shown that a large (in magnitude) negative exchange contribution to the 6 Li quadrupole moment from the three-deuteron configuration cancels almost completely the 'direct' positive contribution due to the αd folding potential. As a result, the total quadrupole moment proves to be close to zero and highly sensitive to fine details of the tensor nucleon-nucleon interaction in the 4 He nucleus and of its wave function

The three-cluster structures in 7Li

International Nuclear Information System (INIS)

Beck, R.; Krivec, R.; Mihailovic, M.V.; Kernforschungszentrum Karlsruhe G.m.b.H.

1981-01-01

A cluster model for the description of light nuclei is investigated which includes the interplay of three-cluster structures with the two-cluster ones and allows molecule-like vibrations of clusters. It is applied to the nucleus 7 Li in order to study the influence of the trhee-cluster structures of the type ( 4 He- 2 H-n) on the low-lying states previously described by two-cluster structures ( 4 He- 3 H) and ( 6 Li-n). An effective central interaction is used in the calculation. The structure of the nucleus 7 Li is described by the two-cluster configuration ( 4 He- 3 H) and the three-cluster configurations ( 4 He- 2 H(Isub(d))-n), with Isub(d) = 0, 1, and the total spin I = 1/2, 3/2. In the wave function of three-cluster structure the pair of values L 1 = 0, L 2 = 1 only is included. The effective nuclear potential V2 of Volkov is used in the calculation. The energy of the ground state described by a single configuration of the two-cluster structure ( 4 He- 3 H) is lowered by 0.66 MeV when this configuration is coupled to two three-cluster configurations and the molecule-like vibration is allowed through solving the Hill-Wheeler equation. Both mechanism have approximately equal effects. The ground-state energy (-38.14 MeV) is 0.3 MeV lower than in the model which describes the 7 Li by a superposition of two-cluster structures ( 4 He- 3 H) and ( 6 Li-n). (orig./HSI)

Configuring PSx tetrahedral clusters in Li-excess Li7P3S11 solid electrolyte

Directory of Open Access Journals (Sweden)

Wo Dum Jung

2018-04-01

Full Text Available We demonstrate that the Li-ion conductivity can be improved by adding a certain amount of Li (x = 0.25–0.5 as a charge carrier to the composition of glass-ceramic Li7+xP3S11. Structural analysis clarified that the structural changes caused by the ratio of ortho-thiophosphate tetrahedra PS43− and pyro-thiophosphate ditetrahedra P2S74− affect the Li-ion conductivity. The ratio of PS43− and P2S74− varies depending on x and the highest Li-ion conductivity (2.5 × 10−3 S cm−1 at x = 0.25. All-solid-state LiNi0.8Co0.15Al0.05O2/Li7.25P3S11/In-metal cell exhibits the discharge capacity of 106.2 mAh g−1. This ion conduction enhancement from excess Li is expected to contribute to the future design of sulfide-type electrolytes.

Breakup Reactions and Exclusive Measurements in the 6,7Li+144Sm Systems

International Nuclear Information System (INIS)

Heimann, D. Martinez; Pacheco, A. J.; Arazi, A.; Figueira, J. M.; Negri, A. E.; Capurro, O. A.; Carnelli, P.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Testoni, J. E.; Monteiro, D. S.; Niello, J. O. Fernandez; Marta, H. D.

2009-01-01

The breakup of the projectile-like nuclei in reactions induced by 30 MeV 6 Li and 7 Li beams on a 144 Sm target have been measured through the coincident detection of the in-plane emitted light particles. The primary ion that undergoes breakup has been identified and the physically meaningful variables that characterize the reaction have been obtained on a purely experimental basis. Distributions have been obtained for both the binary emission angle and for the breakup emission angle in the reference frame of the breakup products.

Electrochemical investigation of Li-Al anodes in oligo(ethylene glycol) dimethyl ether/LiPF6

International Nuclear Information System (INIS)

Zhou, Y.; Wang, X.; Lee, H.; Nam, K.; Haas, O.

2011-01-01

LiPF 6 dissolved in oligo(ethylene glycol) dimethyl ether with a molecular weight 5 g mol -1 was investigated as a new electrolyte (OEGDME5, 1 M LiPF 6 ) for metal deposition and battery applications. At 25 C a conductivity of .48 x 1 -3 S cm -1 was obtained and at 85 C, 3.78 x 1 -3 S cm -1 . The apparent activation barrier for ionic transport was evaluated to be 3.7 kJ mol -1 . OEGDME5, 1 M LiPF 6 allows operating temperature above 1 C with very attractive conductivity. The electrolyte shows excellent performance at negative and positive potentials. With this investigation, we report experimental results obtained with aluminum electrodes using this electrolyte. At low current densities lithium ion reduction and re-oxidation can be achieved on aluminum electrodes at potentials about 28 mV more positive than on lithium electrodes. In situ X-ray diffraction measurements collected during electrochemical lithium deposition on aluminum electrodes show that the shift to positive potentials is due to the negative Gibbs free energy change of the Li-Al alloy formation reaction.

The {sup 7}Li(d, p){sup 8}Li reaction in inverse kinematics at 5.44 MeV/u

Energy Technology Data Exchange (ETDEWEB)

Pakou, A.; Aslanoglou, X.; Sgouros, O.; Soukeras, V. [The University of Ioannina, Department of Physics and HINP, Ioannina (Greece); Keeley, N. [National Centre for Nuclear Research, Otwock (Poland); Cappuzzello, F. [INFN Laboratori Nazionali del Sud, Catania (Italy); Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Acosta, L. [Universidad Nacional Autonoma de Mexico, Instituto de Fisica, Mexico City (Mexico); INFN Sezione di Catania, Catania (Italy); Agodi, C.; Calabrese, S.; Carbone, D.; Cavallaro, M. [INFN Laboratori Nazionali del Sud, Catania (Italy); Foti, A. [Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); INFN Sezione di Catania, Catania (Italy); Marquinez-Duran, G.; Martel, I. [Universidad de Huelva, Departamento de Ciencias Integradas, Facultad de Ciencias Experimentales, Campus de El Carmen, Huelva (Spain); Mazzocco, M.; Strano, E. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); INFN Sezione di Padova, Padova (Italy); Parascandolo, C.; Pierroutsakou, D. [INFN Sezione di Napoli, Napoli (Italy); Rusek, K. [University of Warsaw, Heavy Ion Laboratory, Warsaw (Poland); Zagatto, V.A.B. [Instituto de Fisica da Universidade Federal Fluminense, Niteroi, RJ (Brazil)

2017-08-15

New data are presented for the {sup 7}Li(d, p){sup 8}Li stripping reaction which, together with previously reported elastic scattering data taken in the same experiment, provide a coherent set. These data, plus existing measurements of the elastic scattering and stripping at 6 MeV/u were analysed within the same coupled reaction channels scheme. Good descriptions of the stripping data to the 0.0 MeV 2{sup +} and 0.98 MeV 1{sup +} states of {sup 8}Li were obtained using a set of left angle {sup 8}Li vertical stroke {sup 7}Li + n right angle overlaps taken from the literature, provided that the elastic scattering was also well described. Multi-step reaction paths made significant contributions to the description of the larger angle data. The asymptotic normalisation coefficients are compared with previous determinations. (orig.)

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.

Complete and incomplete fusion dynamics of {sup 6,7}Li + {sup 159}Tb reactions near the Coulomb barrier

Energy Technology Data Exchange (ETDEWEB)

Gautam, Manjeet Singh [Thapar University, School of Physics and Materials Science, Patiala (India); Indus Degree College, Department of Physics, Kinana, Jind, Haryana (India); Grover, Neha; Sharma, Manoj K. [Thapar University, School of Physics and Materials Science, Patiala (India)

2017-01-15

The complete fusion (CF) and incomplete fusion (ICF) cross-sections are estimated for {sup 6,} {sup 7}Li + {sup 159}Tb reactions using the energy-dependent Woods-Saxon potential model (EDWSP model) and dynamical cluster-decay model (DCM). The CF data of the {sup 6}Li + {sup 159}Tb({sup 7}Li + {sup 159}Tb) reaction at above barrier energies is suppressed with reference to expectations of the EDWSP model by 25% (20%) which is smaller than the reported data by ∝ 9% (6%). This suppression is correlated with the projectile breakup effect. The projectiles {sup 6,7}Li are loosely bound systems, which may break up into charged fragments prior to reaching the fusion barrier and subsequently one of the fragment is captured by the target leading to the suppression of fusion data at above barrier energies. The sum of CF and ICF, which is termed as total fusion cross-section (TF), removes the discrepancies between theoretical predictions and the above barrier complete fusion data and hence is adequately explained via the EDWSP model over a wide range of energy spread across the Coulomb barrier. In addition to fusion, the decay mechanism of {sup 6}Li + {sup 159}Tb reaction is studied within the framework of the dynamical cluster-decay model (DCM). The breakup of the projectile ({sup 6}Li) in the entrance channel indicates the presence of ICF, which is investigated further using the collective clusterization approach of DCM. The present theoretical analysis suggests that a larger barrier modification is needed to address the fusion data of chosen reactions in the below barrier energy region. (orig.)

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.

Lithium ion mobility in lithium phosphidosilicates: Crystal structure, {sup 7}Li, {sup 29}Si, and {sup 31}P MAS NMR spectroscopy, and impedance spectroscopy of Li{sub 8}SiP{sub 4} and Li{sub 2}SiP{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Toffoletti, Lorenzo; Landesfeind, Johannes; Klein, Wilhelm; Gasteiger, Hubert A.; Faessler, Thomas F. [Department of Chemistry, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747, Garching bei Muenchen (Germany); Kirchhain, Holger; Wuellen, Leo van [Department of Physics, University of Augsburg, Universitaetsstrasse 1, 86159, Augsburg (Germany)

2016-12-05

The need to improve electrodes and Li-ion conducting materials for rechargeable all-solid-state batteries has drawn enhanced attention to the investigation of lithium-rich compounds. The study of the ternary system Li-Si-P revealed a series of new compounds, two of which, Li{sub 8}SiP{sub 4} and Li{sub 2}SiP{sub 2}, are presented. Both phases represent members of a new family of Li ion conductors that display Li ion conductivity in the range from 1.15(7) x 10{sup -6} Scm{sup -1} at 0 C to 1.2(2) x 10{sup -4} Scm{sup -1} at 75 C (Li{sub 8}SiP{sub 4}) and from 6.1(7) x 10{sup -8} Scm{sup -1} at 0 C to 6(1) x 10{sup -6} Scm{sup -1} at 75 C (Li{sub 2}SiP{sub 2}), as determined by impedance measurements. Temperature-dependent solid-state {sup 7}Li NMR spectroscopy revealed low activation energies of about 36 kJ mol{sup -1} for Li{sub 8}SiP{sub 4} and about 47 kJ mol{sup -1} for Li{sub 2}SiP{sub 2}. Both compounds were structurally characterized by X-ray diffraction analysis (single crystal and powder methods) and by {sup 7}Li, {sup 29}Si, and {sup 31}P MAS NMR spectroscopy. Both phases consist of tetrahedral SiP{sub 4} anions and Li counterions. Li{sub 8}SiP{sub 4} contains isolated SiP{sub 4} units surrounded by Li atoms, while Li{sub 2}SiP{sub 2} comprises a three-dimensional network based on corner-sharing SiP{sub 4} tetrahedra, with the Li ions located in cavities and channels. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Influence of projectile breakup in the elastic scattering of the systems 6,7Li+80Se

Directory of Open Access Journals (Sweden)

Cardona M.A.

2011-10-01

Full Text Available In order to study the influence of the breakup channel in the elastic scattering of the 6,7Li+80Se systems, we have measured angular distributions at center- of-mass energies from 13 ≤ Ec.m. ≤ 24 MeV (0.8VCB up to 1.6VCB . They were analyzed within the framework of the optical model to study the energy dependence of the real and imaginary parts of the nuclear potential. The focus was to investigate the threshold anomaly in those weakly bound systems. The behavior of the calculated potentials as a function of energy indicates that our results are consistent with the dispersion relation. The threshold anomaly was observed in the 7Li+80Se system and the breakup threshold anomaly was confirmed for the 6Li+80Se system.

Improved Dehydrogenation Properties of 2LiNH2-MgH2 by Doping with Li3AlH6

Directory of Open Access Journals (Sweden)

Shujun Qiu

2017-01-01

Full Text Available Doping with additives in a Li-Mg-N-H system has been regarded as one of the most effective methods of improving hydrogen storage properties. In this paper, we prepared Li3AlH6 and evaluated its effect on the dehydrogenation properties of 2LiNH2-MgH2. Our studies show that doping with Li3AlH6 could effectively lower the dehydrogenation temperatures and increase the hydrogen content of 2LiNH2-MgH2. For example, 2LiNH2-MgH2-0.1Li3AlH6 can desorb 6.43 wt % of hydrogen upon heating to 300 °C, with the onset dehydrogenation temperature at 78 °C. Isothermal dehydrogenation testing indicated that 2LiNH2-MgH2-0.1Li3AlH6 had superior dehydrogenation kinetics at low temperature. Moreover, the release of byproduct NH3 was successfully suppressed. Measurement of the thermal diffusivity suggests that the enhanced dehydrogenation properties may be ascribed to the fact that doping with Li3AlH6 could improve the heat transfer for solid–solid reaction.

THE 2H(alpha, gamma6LI REACTION AT LUNA AND BIG BANG NUCLEOSYNTHETIS

Directory of Open Access Journals (Sweden)

Carlo Gustavino

2013-12-01

Full Text Available The 2H(α, γ6Li reaction is the leading process for the production of 6Li in standard Big Bang Nucleosynthesis. Recent observations of lithium abundance in metal-poor halo stars suggest that there might be a 6Li plateau, similar to the well-known Spite plateau of 7Li. This calls for a re-investigation of the standard production channel for 6Li. As the 2H(α, γ6Li cross section drops steeply at low energy, it has never before been studied directly at Big Bang energies. For the first time the reaction has been studied directly at Big Bang energies at the LUNA accelerator. The preliminary data and their implications for Big Bang nucleosynthesis and the purported 6Li problem will be shown.

Reaction cross section measurements for the production of /sup 6/He(805 ms) and /sup 6/Li(175 ms) with 14. 7 Mev neutrons

Energy Technology Data Exchange (ETDEWEB)

Garg, K C; Khurana, C S [Punjabi Univ., Patiala (India). Dept. of Physics

1979-01-01

The automatic electronic programmer developed to handle the millisecond isomers has been utilized to measure the reaction cross-sections for the production of /sup 6/He from sup(7,6)Li((n,d)+(n,p))/sup 6/He and /sup 9/Be(n,..cap alpha..)/sup 6/He reactions and /sup 9/Li from /sup 9/Be(n,p)/sup 9/Li reaction. An on-line gated G.M. counter has been used to follow the decay curves of beta-activities of /sup 6/He(805 ms.) and /sup 9/Li(175 ms.) produced in the reactions. Values of measured cross sections are 10.4 +- 1.0 mb., 10.6 +- 1.1 mb. and 40.3 +- 4.0 mb respectively for the above the three reactions.

Robust Strategy for Crafting Li5Cr7Ti6O25@CeO2 Composites as High-Performance Anode Material for Lithium-Ion Battery.

Science.gov (United States)

Mei, Jie; Yi, Ting-Feng; Li, Xin-Yuan; Zhu, Yan-Rong; Xie, Ying; Zhang, Chao-Feng

2017-07-19

A facile strategy was developed to prepare Li 5 Cr 7 Ti 6 O 25 @CeO 2 composites as a high-performance anode material. X-ray diffraction (XRD) and Rietveld refinement results show that the CeO 2 coating does not alter the structure of Li 5 Cr 7 Ti 6 O 25 but increases the lattice parameter. Scanning electron microscopy (SEM) indicates that all samples have similar morphologies with a homogeneous particle distribution in the range of 100-500 nm. Energy-dispersive spectroscopy (EDS) mapping and high-resolution transmission electron microscopy (HRTEM) prove that CeO 2 layer successfully formed a coating layer on a surface of Li 5 Cr 7 Ti 6 O 25 particles and supplied a good conductive connection between the Li 5 Cr 7 Ti 6 O 25 particles. The electrochemical characterization reveals that Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) electrode shows the highest reversibility of the insertion and deinsertion behavior of Li ion, the smallest electrochemical polarization, the best lithium-ion mobility among all electrodes, and a better electrochemical activity than the pristine one. Therefore, Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) electrode indicates the highest delithiation and lithiation capacities at each rate. At 5 C charge-discharge rate, the pristine Li 5 Cr 7 Ti 6 O 25 only delivers an initial delithiation capacity of ∼94.7 mAh g -1 , and the delithiation capacity merely achieves 87.4 mAh g -1 even after 100 cycles. However, Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) delivers an initial delithiation capacity of 107.5 mAh·g -1 , and the delithiation capacity also reaches 100.5 mAh g -1 even after 100 cycles. The cerium dioxide modification is a direct and efficient approach to improve the delithiation and lithiation capacities and cycle property of Li 5 Cr 7 Ti 6 O 25 at large current densities.

Mixed alkali neodymium orthoborates: K_9Li_3Nd_3(BO_3)_7 and A_2LiNd(BO_3)_2 (A = Rb, Cs)

International Nuclear Information System (INIS)

Chen, Pengyun; Xia, Mingjun; Li, Rukang

2016-01-01

Crystals of mixed alkali neodymium orthoborates, K_9Li_3Nd_3(BO_3)_7 and A_2LiNd(BO_3)_2 (A = Rb, Cs) were obtained by spontaneous crystallization. K_9Li_3Nd_3(BO_3)_7 crystallizes in space group P2/c with cell parameters of a = 11.4524(7) Aa, b = 10.1266(6) Aa, c = 12.3116 (10) Aa, β = 122.0090(10) . In the structure, NdO_8 polyhedra share corners and connect with planer BO_3 groups to form infinite [Nd_3B_3O_2_1]_n chains. These chains are linked by additional BO_3 groups to produce a double layer of [Nd_6B_6O_3_8]_n blocks in the ac plane with K and Li ions filled into the cavities. A_2LiNd(BO_3)_2 (A = Rb, Cs) crystallizes in space group Pbcm, with cell parameters of a = 7.113(2) Aa, b = 9.691(3) Aa and c = 10.135(3) Aa for Rb_2LiNd(BO_3)_2, and a = 7.2113(3) Aa, b = 9.9621(4) Aa, and c = 10.3347(4) Aa for Cs_2LiNd(BO_3)_2. In the structure, NdO_8 polyhedra are corner-sharing with each other and further interlinked by BO_3 groups to comprise the infinite [Nd_4B_4O_2_4] sheets in the bc plane, with Rb/Cs and Li ions occupying the interlayered space. The compounds show effective near-IR emission and their associated lifetimes are obtained by fluorescence spectra. (Copyright copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

X particle effect for 6Li reaction rates calculations

International Nuclear Information System (INIS)

Kocak, G.; Balantekin, A. B.

2009-01-01

The inferred primordial 6 L i-7 L i abundances are different from standard big bang nucleosynthesis results, 6 L i is 1000 times larger and 7 L i is 3 times smaller than the big bang prediction. In big bang nucleosynthesis, negatively charged massive X particles a possible solution to explain this primordial Li abundances problem [1]. In this study, we consider only X particle effect for nuclear reactions to obtain S-factor and reaction rates for Li. All S-factors calculated within the Optical Model framework for d(α,γ)6 L i system. We showed that the enhancement effect of massive negatively charged X particle for 6 L i system reaction rate.(author)

Synthesize and electrochemical characterization of Mg-doped Li-rich layered Li[Li0.2Ni0.2Mn0.6]O2 cathode material

International Nuclear Information System (INIS)

Wang, Dan; Huang, Yan; Huo, Zhenqing; Chen, Li

2013-01-01

Highlights: • Layered Li[Li 0.2 Ni 0.2−x Mn 0.6−x Mg 2x ]O 2 (2x = 0, 0.01, 0.02, 0.05) were synthetized. • Li[Li 0.2 Ni 0.2−x Mn 0.6−x Mg 2x ]O 2 exhibit enhanced electrochemical properties. • The improved performance is attributed to enhanced structure stability. -- Abstract: Mg-doped Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 as a Li-rich cathode material of lithium-ion batteries were prepared by co-precipitation method and ball-milling treatment using Mg(OH) 2 as a dopant. Scanning electron microscopy (SEM), ex situ X-ray powder diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvantatic charge/discharge were used to investigate the effect of Mg doping on structure and electrochemical performance. Compared with the bare material, Mg-doped materials exhibit better cycle stabilities and superior rate capabilities. Li[Li 0.2 Ni 0.195 Mn 0.595 Mg 0.01 ]O 2 displays a high reversible capacity of 226.5 mAh g −1 after 60 cycles at 0.1 C. The excellent cycle performance can be attributed to the improvement in structure stability, which is verified by XRD tests before and after 60 cycles. EIS results show that Mg doping decreases the charge-transfer resistance and enhances the reaction kinetics, which is considered to be the major factor for higher rate performance

7Li production in bouncing supermassive stars

International Nuclear Information System (INIS)

Norgaard, H.; Fricke, K.J.

1976-01-01

Nucleosynthesis in detailed models for bouncing supermassive stars is investigated. We consider a non-rotating 5.2 x 10 5 M(sun) and a rotating 3 x 10 6 M (sun) star and follow the time evolution of the abundances throughout the quasistatic contraction phase as well as through the implosion-explosion. Our numerical network integrations show that explosions of such objects cause predominantly the enrichment of 7 Li. Typical enhancement factors for 7 Li with respect to the 'universal' value of Cameron (1973) are of the order of 1,000, whereas those of 13 C, 15 N and 17 O are of the order of 100 or less. (orig./WL) [de

VUV spectroscopy of pure LiCaAlF6 crystals

International Nuclear Information System (INIS)

Kirm, M.; True, M.; Vielhauer, S.; Zimmerer, G.; Shiran, N.V.; Shpinkov, I.; Spassky, D.; Shimamura, K.; Ichinose, N.

2005-01-01

Reflection, excitation and luminescence spectra of as-grown and X-ray irradiated high-purity LiCaAlF 6 crystals were studied in the temperature range of 10-300 K using synchrotron radiation in VUV. The intrinsic luminescence of samples at 10 K consists of a non-elementary broad band with maximum at 4.4 eV under excitation at 11.45 eV. It is ascribed to the radiative decay of self-trapped excitons. The energy gap is estimated to be 12.65 eV in LiCaAlF 6 . Under interband excitation a red shift of luminescence was observed. The electron-hole recombination leads to the emission peaking at 3.7 eV. The excitation processes and origin of overlapping emissions of LiCaAlF 6 are discussed

Protons scattering on Li isotopes at intermediate energies

International Nuclear Information System (INIS)

Zhusupov, M.A.; Imambekov, O.; Sanfirova, A.V.; Ibraeva, E.T.

2003-01-01

The protons scattering differential cross section on the 6,7,8 Li nuclei are calculated within the framework the Glauber-Sitenko multiple scattering theory at intermediate energies (from 100 to 1000 MeV). In the calculations the multi-cluster wave functions (αt for 7 Li, αnp for 6 Li, and αtn for 8 Li) considering within potential cluster model have been used. Differential cross sections for 6 Li, 7 Li, 8 Li and 9 Li nuclei are similar: absolute cross sections are almost the same, diffraction minimum for large A shifting to the field of the least scattering angles that reflecting increase of the material radius. For the 11 Li the differential cross section absolute value is smaller about in two time than for the rest isotopes. At present it is reliably established, that the 11 Li nucleus has an exotic structure - the nine-nucleon core ( 9 Li) around which the two-neutron halo is rotating. The principal characteristics of the Li nuclei are presented in tabular form

Benchmark Linelists and Radiative Cooling Functions for LiH Isotopologues

Science.gov (United States)

Diniz, Leonardo G.; Alijah, Alexander; Mohallem, José R.

2018-04-01

Linelists and radiative cooling functions in the local thermodynamic equilibrium limit have been computed for the six most important isotopologues of lithium hydride, 7LiH, 6LiH, 7LiD, 6LiD, 7LiT, and 6LiT. The data are based on the most accurate dipole moment and potential energy curves presently available, the latter including adiabatic and leading relativistic corrections. Distance-dependent reduced vibrational masses are used to account for non-adiabatic corrections of the rovibrational energy levels. Even for 7LiH, for which linelists have been reported previously, the present linelist is more accurate. Among all isotopologues, 7LiH and 6LiH are the best coolants, as shown by the radiative cooling functions.

Synthesis and characterization of Li2FeP2O7/C nanocomposites as cathode materials for Li-ion batteries

International Nuclear Information System (INIS)

Du, Juan; Jiao, Lifang; Wu, Qiong; Liu, Yongchang; Zhao, Yanping; Guo, Lijing; Wang, Yijing; Yuan, Huatang

2013-01-01

Highlights: • Li 2 FeP 2 O 7 /C were prepared by a simple solid-state reaction. • Carbon coating and reducing particle size are adopted to improve the discharge capacity. • The detailed study about the electrochemical properties of Li 2 FeP 2 O 7 is scarce. • Li 2 FeP 2 O 7 /C show superior electrochemical properties. -- Abstract: The pristine Li 2 FeP 2 O 7 and Li 2 FeP 2 O 7 /C nanocomposites with different content of carbon have been successfully synthesized via a simple solid-state reaction, using cheap glucose as carbon source. XRD and EDS patterns demonstrate the high purity of the products. SEM images exhibit that the size of the particles is about 50–500 nm. Electrochemical measurements reveal that carbon coating and reducing particle size significantly enhance the electrochemical performances of Li 2 FeP 2 O 7 . Particularly, the Li 2 FeP 2 O 7 /C sample with a carbon content of 4.88 wt.% displays the best performance with a specific discharge capacity of 103.1 mAh g −1 at 0.1 C, which is 93.7% of its one-electron theoretical capacity, meaning 110 mAh g −1 . Meanwhile, it shows favorable cycling stability and excellent rate performance, indicating its potential applicability in Li-ion batteries in the long term

Magnetic signature of charge ordering in Li[Mn sub 1 sub . sub 9 sub 6 Li sub 0 sub . sub 0 sub 4]O sub 4 and Li sub 0 sub . sub 2 [Mn sub 1 sub . sub 9 sub 6 Li sub 0 sub . sub 0 sub 4]O sub 4

CERN Document Server

Verhoeven, V W J; Mulder, F M

2002-01-01

The stoichiometric compound LiMn sub 2 O sub 4 is known to show charge ordering with well-defined Mn sup 3 sup + and Mn sup 4 sup + sites just below room temperature (RT). Above RT the electrons are hopping rapidly between sites. For lithium-ion batteries the material Li[Mn sub 1 sub . sub 9 sub 6 Li sub 0 sub . sub 0 sub 4]O sub 4 is technologically relevant. Due to the small amount of Li on the Mn site, the low-T regular ordering of the Mn charge appears to be destroyed completely, as is evidenced by neutron diffraction in the magnetically ordered state. However, the charges are still fixed in an irregular fashion, as can also be deduced from sup 7 Li nuclear magnetic resonance measurements. In the lithium-extracted compound Li sub 0 sub . sub 2 [Mn sub 1 sub . sub 9 sub 6 Li sub 0 sub . sub 0 sub 4]O sub 4 , predominantly Mn sup 4 sup + is present. Neutron diffraction in the magnetically ordered state shows a well-defined antiferromagnetic ordering, with doubling of the unit cell in three directions. Clear...

Irradiation cryostat for LiH and LiD polarized solid targets

International Nuclear Information System (INIS)

Goertz, S.

1991-01-01

Scattering experiments with polarized nucleon targets are an important tool to understand the nuclear spin structure. Pion photoproduction experiments on polarized protrons and neutrons as well as measurements of the neutron and deuteron formfactors will be performed at ELSA. 7 LiH and 6 LiD seem to be attractive target materials for these experiments, because they offer high proton and deuteron polarisation, respectively. Expecially 6 LiD has further very important advantages compared to the common deuteron target materials as d-Butanol and ND 3 . This work describes the mechanism of DNP (Dynamic Nuclear Polarization) in LiH and LiD and gives a view on the nature of the so-called paramagnetic impurities in these materials. In order to maximize the nuclear polarization, the production of these radicals have to take place under well defined temperature conditions. Therefore the first version of an irradiation cryostat was built and tested in regard to its cooling power and temperature adjustment. (orig.)

Preparation and characterization of three 7Be targets for the measurement of the 7Be(n, p)7Li and 7Be(n, α)7Li reaction cross sections

Science.gov (United States)

Maugeri, E. A.; Heinitz, S.; Dressler, R.; Barbagallo, M.; Ulrich, J.; Schumann, D.; Colonna, N.; Köster, U.; Ayranov, M.; Vontobel, P.; Mastromarco, M.; Schell, J.; Correia, J. Martins; Stora, T.; n TOF Collaboration

2018-05-01

This manuscript describes the production of three targets obtained by implantation of different activities of 7Be into thin aluminium disks. Two of the produced targets were used to measure the 7Be(n, p)7Li cross section in the energy range of interest for the Big-Bang Nucleosynthesis. A third target was used to measure the cross sections of 7Be(n, p)7Li and 7Be(n, α)7Li nuclear reactions with cold and thermal neutrons, respectively. This paper describes also the characterization of the first two targets, performed after the neutron irradiation, in terms of implanted 7Be activities and spatial distributions.

Contribution to the study of excited levels of {sup 7}Be obtained from the reaction {sup 6}Li (p, {alpha}); Contribution a l'etude des niveaux excites du {sup 7}Be obtenus par la reaction {sup 6}Li (p, {alpha})

Energy Technology Data Exchange (ETDEWEB)

Beaumevieille, H. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-05-01

The interpretation of the results of the reaction {sup 6}Li (p, {alpha}) in the energy range 100 keV to 3 MeV has been done with the next levels of {sup 7}Be : 3/2- (5,9 MeV), 3/2+ (6,2 MeV), 5/2- (7,18 MeV) and a level the characteristics of which may be 1/2+ or {sup 4}P (9,5 MeV). (author) [French] L'interpretation des resultats de la reaction {sup 6}Li (p, {alpha}) dans la gamme d'energie 100 keV a 3 MeV a ete faite avec les niveaux suivants du {sup 7}Be : 3/2- (5,9 MeV), 3/2 + (6,2 MeV), 5/2- (7,18 MeV) et un niveau dont les caracteristiques doivent etre 1/2+ ou {sup 4}P (9,5 MeV). (auteur)

Contribution to the study of excited levels of {sup 7}Be obtained from the reaction {sup 6}Li (p, {alpha}); Contribution a l'etude des niveaux excites du {sup 7}Be obtenus par la reaction {sup 6}Li (p, {alpha})

Energy Technology Data Exchange (ETDEWEB)

Beaumevieille, H [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-05-01

The interpretation of the results of the reaction {sup 6}Li (p, {alpha}) in the energy range 100 keV to 3 MeV has been done with the next levels of {sup 7}Be : 3/2- (5,9 MeV), 3/2+ (6,2 MeV), 5/2- (7,18 MeV) and a level the characteristics of which may be 1/2+ or {sup 4}P (9,5 MeV). (author) [French] L'interpretation des resultats de la reaction {sup 6}Li (p, {alpha}) dans la gamme d'energie 100 keV a 3 MeV a ete faite avec les niveaux suivants du {sup 7}Be : 3/2- (5,9 MeV), 3/2 + (6,2 MeV), 5/2- (7,18 MeV) et un niveau dont les caracteristiques doivent etre 1/2+ ou {sup 4}P (9,5 MeV). (auteur)

Basic technology for {sup 6}Li enrichment using an ionic-liquid impregnated organic membrane

Energy Technology Data Exchange (ETDEWEB)

Hoshino, Tsuyoshi, E-mail: hoshino.tsuyoshi@jaea.go.jp [Blanket Irradiation and Analysis Group, Fusion Research and Development Directorate, Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Higashi Ibaraki-gun, Ibaraki 311-1393 (Japan); Terai, Takayuki [The Institute of Engineering Innovation and Department of Nuclear Engineering and Management School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

2011-10-01

The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 ({sup 6}Li) in tritium breeding materials. However, natural Li contains only about 7.6 at.% {sup 6}Li. In this paper, a new lithium isotope separation technique using an ionic-liquid impregnated organic membrane is proposed. In order to separate and concentrate lithium isotopes, only lithium ions are able to move through the membrane by electrodialysis between the cathode and the anode in lithium solutions. Preliminary experiments of lithium isotope separation were conducted using this phenomenon. Organic membranes impregnated with TMPA-TFSI and PP13-TFSI as ionic liquids were prepared, and the relationship between the {sup 6}Li separation coefficient and the applied electrodialytic conditions was evaluated using them. The results showed that the {sup 6}Li isotope separation coefficient in this method (about 1.1-1.4) was larger than that in the mercury amalgam method (about 1.06).

Modeling Li-ion conductivity in LiLa(PO3)4 powder

International Nuclear Information System (INIS)

Mounir, Ferhi; Karima, Horchani-Naifer; Khaled, Ben Saad; Mokhtar, Férid

2012-01-01

Polycrystalline powder and single-crystal of LiLa(PO 3 ) 4 are synthesized by solid state reaction and flux technique, respectively. A morphological description of the obtained product was made based on scanning electron microscopy micrographs. The obtained powder was characterized by X-ray powder diffraction, FTIR and Raman spectroscopies. Ionic conductivity of the LiLa(PO 3 ) 4 powder was measured and evaluated over a temperature range from 553 to 913 K. Single crystals of LiLa(PO 3 ) 4 are characterized by single-crystal X-ray diffraction. The LiLa(PO 3 ) 4 structure was found to be isotypic with LiNd(PO 3 ) 4 . It crystallizes in the monoclinic system with space group C2/c and cell parameters: a=16.635(6) Å, b=7.130(3) Å, c=9.913(3) Å, β=126.37(4)°, V=946.72(6) Å 3 and Z=4. The LiLa(PO 3 ) 4 structure was described as an alternation between spiraling chains (PO 3 ) n and (La 3+ , Li + ) cations along the b direction. The small Li + ions, coordinated to four oxygen atoms, were located in the large connected cavities created between the LaO 8 polyhedra and the polyphosphate chains. The jumping of Li + through tunnels of the crystalline network was investigated using complex impedance spectroscopy. The close value of the activation energies calculated through the analysis of conductivity data and loss spectra indicate that the transport in the investigated system is through hopping mechanism. The correlation between ionic conductivity of LiLa(PO 3 ) 4 and its crystallographic structure was investigated and the most probably transport pathway model was determined.

6Li-doped silicate glass for thermal neutron shielding

International Nuclear Information System (INIS)

Stone, C.A.; Blackburn, D.H.; Kauffman, D.A.; Cranmer, D.C.; Olmez, I.

1994-01-01

Glass formulations are described that contain high concentrations of 6 Li and are suitable for use as thermal neutron shielding. One formulation contained 31 mol% of 6 Li 2 O and 69 mol% of SiO 2 . Studies were performed on a second formulation that contained as much as 37 mol% of 6 Li 2 O and 59 mol% of SiO 2 , with 4 mol% Al 2 O 3 added to prevent crystallization at such high 6 Li 2 O concentrations. These lithium silicate glasses can be formed into a variety of shapes using conventional glass fabrication techniques. Examples include flat plates, disks, hollow cylinders, and other more complex geometries. Both in-beam and in-core experiments have been performed to study the use and durability of Li silicate glasses. In-core experiments show the glass can withstand the intense radiation fields near the core of a reactor. The neutron attenuation of the glasses used in these studies was 90%/mm. In-beam studies show that the glass is effective for reducing the gamma-ray and neutron fields near experiments. ((orig.))

Improved the lithium storage capability of BaLi2Ti6O14 by electroless silver coating

International Nuclear Information System (INIS)

Lin, Xiaoting; Wang, Pengfei; Li, Peng; Yu, Haoxiang; Qian, Shangshu; Shui, Miao; Wang, Dongjie; Long, Nengbing; Shu, Jie

2015-01-01

Highlights: • BaLi 2 Ti 6 O 14 /Ag is fabricated via a facile electroless deposition. • Highly dispersed Ag nanoparticles are successively coated on BaLi 2 Ti 6 O 14 . • BaLi 2 Ti 6 O 14 /Ag is used as anode material for lithium storage. • BaLi 2 Ti 6 O 14 /Ag exhibits improved lithium storage capability. - Abstract: To form BaLi 2 Ti 6 O 14 /Ag, highly dispersed Ag nanoparticles are successfully deposited on the surface of BaLi 2 Ti 6 O 14 by a simple chemical deposition method. The morphology, quantity and size of Ag nanoparticles in BaLi 2 Ti 6 O 14 /Ag composites are significantly influenced by the Ag coating contents. Electrochemical results show that Ag nanoparticles play a positive role in reducing redox polarization and improving electrical conductivity of BaLi 2 Ti 6 O 14 during lithiation/delithiation processes. Among all the as-obtained products, 6 wt.% Ag coated BaLi 2 Ti 6 O 14 shows the highest initial charge specific capacity of 160 mAh g −1 at the current density of 100 mA g −1 (1C), which is much higher than the 149.1 mAh g −1 for bare BaLi 2 Ti 6 O 14 . After 100 charge/discharge cycles, the reversible capacity can be maintained at 117.0 mAh g −1 . Moreover, this sample also shows excellent rate performance with high reversible charge capacities of 147.5, 139.7, 132.6, and 126.7 mAh g −1 at the rates of 2C, 3C, 4C and 5C, respectively. Compared with bare BaLi 2 Ti 6 O 14 , the superior electrochemical performance indicates that BaLi 2 Ti 6 O 14 /Ag can be a good anode material in lithium ion batteries.

Study of the Unbound Nuclei $^{10}$Li and $^{7}$He at REX ISOLDE

CERN Multimedia

2002-01-01

% IS367\\\\ \\\\ We propose to study the two unbound nuclei $^{10}$Li and $^{7}$He produced in simple one-neutron pick-up reactions induced by intense beams of $^{9}$Li and $^{6}$He from REX ISOLDE in $^{9}$Be and CD$_{2}$ targets.\\\\ \\\\The unbound nucleus $^{10}$Li is a binary subsystem of the two-neutron halo nucleus $^{11}$Li and its structure is of key importance for theoretical investigations of the halo structure. We propose two different reactions, which together would give an unambiguous determination of lowest $\\textit{s-}$ and $\\textit{p-}$wave resonances in the ($^{9}$Li+n) system.\\\\ \\\\Similarly $^{7}$He plays an important role in the dissociation of $^{8}$He, a drip-line nucleus with an $\\alpha$+4n five-body structure. The aim of our investigation is to search for an excited 1/2$^{-}$ state above the $^{7}$He 3/2$^{-}$ ground state in order to investigate its cluster structure. \\\\ \\\\

Studies on the thermal decomposition kinetics of LiPF6 and LiBC4O8

Indian Academy of Sciences (India)

WINTEC

ion batteries. The current electrolyte generally used in lithium-ion batteries is mainly composed of LiPF6 and a blend of alkyl carbonates. LiPF6 has been widely adopted for more than a decade, owing to its neces- sary pre-requisites for use in lithium ion batteries, for example, it is easily soluble in various solvents, can lead ...

The Watanabe model for 6Li-nucleus optical potential

International Nuclear Information System (INIS)

Abul-Magd, A.Y.; Rabie, A.; El-Gazzar, M.A.

1980-09-01

Optical potentials for the scattering of 6 Li projectiles are calculated using the Watanabe model and an α+d cluster model wave function for 6 Li. Reasonable fits to the elastic differential cross-section and vector polarization are obtained. (author)

Technology of preparation for low density 6Li(H,D) solid micro-target

International Nuclear Information System (INIS)

Wang Xisheng; Zeng Jiaquan; Li Qiang

2002-01-01

Low density 6 Li(H,D) micro-targets are prepared by loose sintering 6 LiH or 6 LiD powder in a tiny gold cylinder and soaking for 30 min up to 430 degree C at the rate of 10 degree C/h in argon. The dimension of the micro-targets is as tiny as 0.6-1.0 mm for diameter and 1-2 mm for length. Densities of 6 LiH and 6 LiD without Parylene C is (0.283 +- 0.009) g/cm 3 and (0.369 +- 0.009) g/cm 3 , respectively while 6 LiD targets with Parylene C is only (0.301 +- 0.010) g/cm 3 . The Parylene C has no effect on purity, deuterium abundance and 6 Li abundance of the sintered micro-targets. It's effective to keep 6 Li(H,D) purity by strict control of argon atmosphere

{sup 7}Li and {sup 23}Na NMR measurements on (Na{sub 0.75}Li{sub 0.25}){sub 2}IrO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Dey, Tusharkanti; Freund, Friedrich; Manni, Soham; Gegenwart, Philipp [EP-VI, Electronic Correlations and Magnetism, University of Augsburg (Germany); Prinz-Zwick, Markus; Schaedler, Martina; Buettgen, Norbert [EP-V, Electronic Correlations and Magnetism, University of Augsburg (Germany); Mahajan, Avinash [EP-V, Electronic Correlations and Magnetism, University of Augsburg (Germany); IIT Bombay (India)

2016-07-01

An experimental realization of the proposed Kitaev spin-liquid phase in Na{sub 2}IrO{sub 3} and Li{sub 2}IrO{sub 3} is still a big challenge. Efforts to suppress the magnetic ordering in Na{sub 2}IrO{sub 3} by substituting isoelectronic Li in the Na site was partially successful. An earlier report suggests the optimum doping to be 25% where the magnetic ordering is suppressed to 6 K while the structure remains undisturbed. Interestingly, for the (Na{sub 0.75}Li{sub 0.25}){sub 2}IrO{sub 3} sample Na and Li are crystallographically ordered where the Li ions reside at the centre of the Ir honeycombs. We have studied the material using both {sup 7}Li and {sup 23}Na NMR. Results of our spectra, spin-lattice and spin-spin relaxation measurements will be discussed in the poster.

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.

Quantum-chemical study of structure and stability of hydride complexes Li4BeH6 and Li4MgH6

International Nuclear Information System (INIS)

Zyubin, A.S.; Charkin, O.P.; Klabo, D.A.; Shlojfer, P.R.

1993-01-01

Nonempirical calculations of geometrical structure, electronic structure and relative energies of a wide range of different configurations of Li 4 MH 6 (M = Be, Mg) molecules were conducted in order to predict the existence of complex hydrides with high hydrogen content. It was revealed, that Li 4 MH 6 molecules were stable to decomposition and could exist in isolated state or in inert matrices. Li 4 MH 6 systems are noted for existence of several isomers with energy, close to the basic structure. The presence of M atoms with coordination number (CN) equal to four is considered to be their common feature. The structure, where CN of Be and Mg is equal to three, are less stable. Configurations, including M atoms with CN = 5 or 6, are much more unfavorable from the viewpoint of energy

Formation and reduction behaviors of zirconium oxide compounds in LiCl–Li{sub 2}O melt at 923 K

Energy Technology Data Exchange (ETDEWEB)

Sakamura, Yoshiharu, E-mail: sakamura@criepi.denken.or.jp [Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwadokita, Komae-shi, Tokyo 201-8511 (Japan); Iizuka, Masatoshi [Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwadokita, Komae-shi, Tokyo 201-8511 (Japan); Kitawaki, Shinichi; Nakayoshi, Akira; Kofuji, Hirohide [International Research Institute for Nuclear Decommissioning (IRID), 2-23-1 Nishi-shimbashi, Minato-ku, Tokyo 105-0003 (Japan); Japan Atomic Energy Agency (JAEA), 4-33 Muramatsu, Tokai-mura, Naka-gun, Ibaraki 319-1194 (Japan)

2015-11-15

The reduction behaviors of ZrO{sub 2}, Li{sub 2}ZrO{sub 3} and (U,Pu,Zr)O{sub 2} in a LiCl–Li{sub 2}O salt bath at 923 K were investigated. This study was conducted as part of a feasibility study on the pyrochemical treatment of damaged fuel debris generated by severe accidents at light water reactors. It was demonstrated in electrolytic reduction tests that the uranium in synthetic corium specimens of (U,Pu,Zr)O{sub 2} with various ZrO{sub 2} contents could be reduced to the metallic form and that part of the zirconium was converted to Li{sub 2}ZrO{sub 3}. Zirconium metal and Li{sub 2}ZrO{sub 3} were obtained by the reduction of ZrO{sub 2}. The reduction of Li{sub 2}ZrO{sub 3} did not proceed even in LiCl containing no Li{sub 2}O. Moreover, the stable chemical forms of the ZrO{sub 2}–Li{sub 2}O complex oxide were investigated as a function of the Li{sub 2}O concentration in LiCl. ZrO{sub 2} was converted to Li{sub 2}ZrO{sub 3} at a Li{sub 2}O concentration of 0.018 wt%. As the Li{sub 2}O concentration was increased, Li{sub 2}ZrO{sub 3} was converted to Li{sub 6}Zr{sub 2}O{sub 7} and then to Li{sub 8}ZrO{sub 6}. It is suggested that the removal of Li{sub 2}ZrO{sub 3} from the reduction product is a key point in the pyrochemical treatment of corium. - Highlights: • The uranium in (U,Pu,Zr)O{sub 2} could be reduced to the metallic form in LiCl–Li{sub 2}O. • Part of the zirconium was converted to Li{sub 2}ZrO{sub 3} during electrolytic reduction. • Li{sub 6}Zr{sub 2}O{sub 7} and Li{sub 8}ZrO{sub 6} formed at high Li{sub 2}O concentrations in LiCl.

Relevance of LiPF6 as Etching Agent of LiMnPO4 Colloidal Nanocrystals for High Rate Performing Li-ion Battery Cathodes.

Science.gov (United States)

Chen, Lin; Dilena, Enrico; Paolella, Andrea; Bertoni, Giovanni; Ansaldo, Alberto; Colombo, Massimo; Marras, Sergio; Scrosati, Bruno; Manna, Liberato; Monaco, Simone

2016-02-17

LiMnPO4 is an attractive cathode material for the next-generation high power Li-ion batteries, due to its high theoretical specific capacity (170 mA h g(-1)) and working voltage (4.1 V vs Li(+)/Li). However, two main drawbacks prevent the practical use of LiMnPO4: its low electronic conductivity and the limited lithium diffusion rate, which are responsible for the poor rate capability of the cathode. The electronic resistance is usually lowered by coating the particles with carbon, while the use of nanosize particles can alleviate the issues associated with poor ionic conductivity. It is therefore of primary importance to develop a synthetic route to LiMnPO4 nanocrystals (NCs) with controlled size and coated with a highly conductive carbon layer. We report here an effective surface etching process (using LiPF6) on colloidally synthesized LiMnPO4 NCs that makes the NCs dispersible in the aqueous glucose solution used as carbon source for the carbon coating step. Also, it is likely that the improved exposure of the NC surface to glucose facilitates the formation of a conductive carbon layer that is in intimate contact with the inorganic core, resulting in a high electronic conductivity of the electrode, as observed by us. The carbon coated etched LiMnPO4-based electrode exhibited a specific capacity of 118 mA h g(-1) at 1C, with a stable cycling performance and a capacity retention of 92% after 120 cycles at different C-rates. The delivered capacities were higher than those of electrodes based on not etched carbon coated NCs, which never exceeded 30 mA h g(-1). The rate capability here reported for the carbon coated etched LiMnPO4 nanocrystals represents an important result, taking into account that in the electrode formulation 80% wt is made of the active material and the adopted charge protocol is based on reasonable fast charge times.

Dynamics of complete and incomplete fusion of 6,7Li, 15N and 16O with a 209Bi target

International Nuclear Information System (INIS)

Gautam, Manjeet Singh; Vinod, K.; Khatri, Hitender

2017-01-01

The dynamics of complete and incomplete fusion of 6,7 Li, 15 N and 16 O with a common target ( 209 Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ( 209 Bi) gets suppressed at above barrier energies. In the case of the 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of 6,7 Li + 209 Bi reactions. In contrast to this, the observed fusion dynamics of 15 N + 209 Bi and 16 O + 209 Bi reactions, wherein the collective excitations such as two phonon, three phonon vibrational states contribute

Analysis of tritium production in concentric spheres of oralloy and 6LiD irradiated by 14-MeV neutrons

International Nuclear Information System (INIS)

Fawcett, L.R. Jr.; Roberts, R.R. II; Hunter, R.E.

1988-03-01

Tritium production and activation of radiochemical detector foils in a sphere of 6 LiD with an oralloy core irradiated by a central source of 14-MeV neutrons have been calculated and compared with experimental measurements. The experimental assembly consisted of an oralloy sphere surrounded by three solid 6 LiD concentric shells with ampules of 6 LiH and 7 LiH and activation foils located in several positions throughout the assembly. The Los Alamos Monte Carlo Neutron Photon Transport Code (MCNP) was used to calculate neutron transport throughout the system, tritium production in the ampules, and foil activation. The overall experimentally observed-to-calculated ratios of tritium production were 0.996 +- 2.5% in 6 Li ampules and 0.903 +- 5.2% in 7 Li ampules. Observed-to-calculated ratios for foil activation are also presented. 11 refs., 4 figs., 7 tabs

Formation of positive cluster ions Li(n) Br (n = 2-7) and ionization energies studied by thermal ionization mass spectrometry.

Science.gov (United States)

Veličković, S R; Đustebek, J B; Veljković, F M; Veljković, M V

2012-05-01

Clusters of the type Li(n)X (X = halides) can be considered as potential building blocks of cluster-assembly materials. In this work, Li(n)Br (n = 2-7) clusters were obtained by a thermal ionization source of modified design and selected by a magnetic sector mass spectrometer. Positive ions of the Li(n)Br (n = 4-7) cluster were detected for the first time. The order of ion intensities was Li(2)Br(+) > Li(4)Br(+) > Li(5)Br(+) > Li(6)Br(+) > Li(3)Br(+). The ionization energies (IEs) were measured and found to be 3.95 ± 0.20 eV for Li(2)Br, 3.92 ± 0.20 eV for Li(3)Br, 3.93 ± 0.20 eV for Li(4)Br, 4.08 ± 0.20 eV for Li(5)Br, 4.14 ± 0.20 eV for Li(6)Br and 4.19 ± 0.20 eV for Li(7)Br. All of these clusters have a much lower ionization potential than that of the lithium atom, so they belong to the superalkali class. The IEs of Li(n)Br (n = 2-4) are slightly lower than those in the corresponding small Li(n) or Li(n)H clusters, whereas the IEs of Li(n)Br are very similar to those of Li(n) or Li(n)H for n = 5 and 6. The thermal ionization source of modified design is an important means for simultaneously obtaining and measuring the IEs of Li(n)Br (n = 2-7) clusters (because their ions are hermodynamically stable with respect to the loss of lithium atoms in the gas phase) and increasingly contributes toward the development of clusters for practical applications. Copyright © 2012 John Wiley & Sons, Ltd.

Ternary nitrides for hydrogen storage: Li-B-N, Li-Al-N and Li-Ga-N systems

International Nuclear Information System (INIS)

Langmi, Henrietta W.; McGrady, G. Sean

2008-01-01

This paper reports an investigation of hydrogen storage performance of ternary nitrides based on lithium and the Group 13 elements boron, aluminum and gallium. These were prepared by ball milling Li 3 N together with the appropriate Group 13 nitride-BN, AlN or GaN. Powder X-ray diffraction of the products revealed that the ternary nitrides obtained are not the known Li 3 BN 2 , Li 3 AlN 2 and Li 3 GaN 2 phases. At 260 deg. C and 30 bar hydrogen pressure, the Li-Al-N ternary system initially absorbed 3.7 wt.% hydrogen, although this is not fully reversible. We observed, for the first time, hydrogen uptake by a pristine ternary nitride of Li and Al synthesized from the binary nitrides of the metals. While the Li-Ga-N ternary system also stored a significant amount of hydrogen, the storage capacity for the Li-B-N system was near zero. The hydrogenation reaction is believed to be similar to that of Li 3 N, and the enthalpies of hydrogen absorption for Li-Al-N and Li-Ga-N provide evidence that AlN and GaN, as well as the ball milling process, play a significant role in altering the thermodynamics of Li 3 N

Production and characterization of thin 7Li targets fabricated by ion implantation

International Nuclear Information System (INIS)

Cruz, J.; Fonseca, M.; Luis, H.; Mateus, R.; Marques, H.; Jesus, A.P.; Ribeiro, J.P.; Teodoro, O.M.N.D.; Rolfs, C.

2009-01-01

Very high fluence implantation of 7 Li + ions was used to promote the formation of a thin and high density 7 Li target in the surface region of Al samples. The implanted volume was characterized by particle induced gamma-ray emission, Rutherford backscattering spectrometry, X-ray photoelectron spectroscopy and nuclear reaction analysis, revealing that the implanted surface is a combination of Li 2 CO 3 , metallic lithium, LiOH and C, with almost no Al present. Radiation damage effects by proton beams were studied by observing the evolution of the 7 Li(p, α) 4 He nuclear reaction yield with the accumulated charge, at different proton energies, revealing high stability of the produced Li target.

Two-proton pickup studies with the (6Li,8B) reaction

International Nuclear Information System (INIS)

Weisenmiller, R.B.

1976-01-01

The ( 6 Li, 8 B) reaction has been investigated on targets of 26 Mg, 24 Mg, 16 O, 13 C, 12 C, 11 B, 10 B, and 9 Be at a bombarding energy of 80.0 MeV, and on targets of 16 O, 12 C, 9 Be, 7 Li, and 6 Li at a bombarding energy of 93.3 MeV. Only levels consistent with direct, single-step two-proton pickup reaction mechanisms were observed to be strongly populated. On T/sub z/ = 0 targets, the spectroscopic selectivity of this reaction resembles that of the analogous (p,t) reaction. Additionally, these data demonstrate the dominance of spatially symmetric transfer of the two protons. On T/sub z/ greater than 0 targets the ( 6 Li, 8 B) reaction was employed to locate two previously unreported levels (at 7.47 +- 0.05 MeV and 8.86 +- 0.07 MeV) in the T/sub z/ = 2 nuclide 24 Ne and to establish the low-lying 1p-shell states in the T/sub z/ = 3 / 2 nuclei 11 Be, 9 Li, and 7 He. However, no evidence was seen for any narrow levels in the T/sub z/ = 3 / 2 nuclide 5 H nor for any narrow excited states in 7 He. The angular distributions reported here are rather featureless and decrease monotonically with increasing angle. This behavior can be shown by a semi-classical reaction theory to be a consequence of the reaction kinematics. A semi-classical approach also suggests that the kinematic term in the transition matrix element is only weakly dependent upon the angular momentum transfer (which is consistent with simple Distorted Wave Born Approximation calculations). However, only qualitative agreement was obtained between the observed relative transition yields and semi-classical predictions, using the two-nucleon coefficients of fractional parentage of Cohen and Kurath, probably due to the limitations of the semi-classical reaction theory

Quasi-elastic Scattering Measurements in the 6,7Li+144Sm Systems

International Nuclear Information System (INIS)

Capurro, O. A.; Arazi, A.; Fernandez Niello, J. O.; Figueira, J. M.; Marti, G. V.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Monteiro, D. S.; Otomar, D. R.; Gomes, P. R. S.; Guimaraes, V.

2009-01-01

In the present work, results of measurements of quasi-elastic scattering cross sections using a silicon-telescope detector at backward angles are reported. They allowed us to deduce fusion barrier distributions from the first derivative of the corresponding excitation function (-d(dσ qes /dσ Rut )/dE). We report data for the systems 6,7 Li on 144 Sm which are characterized by loosely bound projectiles onto a closed neutron shell target. The experimental excitation functions and the associated barrier distributions are compared for both systems.

LiFSI vs. LiPF6 electrolytes in contact with lithiated graphite: Comparing thermal stabilities and identification of specific SEI-reinforcing additives

International Nuclear Information System (INIS)

Eshetu, Gebrekidan Gebresilassie; Grugeon, Sylvie; Gachot, Grégory; Mathiron, David; Armand, Michel; Laruelle, Stephane

2013-01-01

Lithium bis(fluorosulfonyl) imide (LiFSI) is regarded as an alternative to the classical LiPF 6 salt in today's LiFePO 4 /graphite-based Li-ion batteries electrolyte owing to its slightly higher conductivity and lower fluorine content. In an attempt to better evaluate the safety issues, here we report the comparative study of the LiFSI and LiPF 6 based electrolyte/lithiated graphite interface thermal behavior. DSC measurements with LiFSI-based electrolyte reveal a sharp exotherm with large heat release though at higher onset and peak temperatures compared to LiPF 6 -based electrolyte. With the help of GC/MS, 19 F NMR and ESI-HRMS analyses, we assume that this highly energetic peak around 200 °C, which is dependant upon the lithium content, is mainly related to electrochemical reduction of FSI − anion. In a strategy to limit the probability and damage of thermal runaway event, electrolyte additives such as vinylene carbonate (VC), fluoro ethylene carbonate (FEC), di-isocyanato hexane (DIH) and toluene di-isocyanate (TDI) have been investigated and shown to significantly lower the energy associated with the exothermic phenomenon

Enhanced electrochemical performance of LiMnPO4 by Li+-conductive Li3VO4 surface coatings

International Nuclear Information System (INIS)

Dong, Youzhong; Zhao, Yanming; Duan, He; Liang, Zhiyong

2014-01-01

By a simple wet ball-milling method, Li 3 VO 4 -coated LiMnPO 4 samples were prepared successfully for the first time. The thin Li 3 VO 4 coating layer with a three-dimensional Li + -ion transport path and high mobility of Li + -ion strongly adhered to the LiMnPO 4 material reduces Mn dissolution and increases the Li + flux through the surface of the LiMnPO 4 itself by preventing formation of phases on the surface that would normally block Li + as well as Li + -ion permeation into the surface of the LiMnPO 4 electrode and therefore improve the rate capability as well as the cycling stability of LiMnPO 4 materials. The electrochemical testing shows that the 5% Li 3 VO 4 -coated LiMnPO 4 sample shows a clear voltage plateau in the charge curves and a much higher reversible capacity at different discharge rates compared with the pristine LiMnPO 4 . EIS results also show that the surface charge transfer resistance and Warburg impedance of the Li 3 VO 4 -coated LiMnPO 4 samples significantly decreased. The surface charge transfer resistance and Warburg impedance for the pristine LiMnPO 4 are 955.1 Ω and 400.3 Ω, respectively. While, for the 5% Li 3 VO 4 -coated LiMnPO 4 , the value are only 400.2 Ω and 283.6 Ω, respectively. The surface charge transfer resistance decreases more than half. All of the improved performance will be favorable for application of the LiMnPO 4 in high-power lithium ion batteries

Fusion of 6Li with 159Tb at near-barrier energies

International Nuclear Information System (INIS)

Pradhan, M. K.; Mukherjee, A.; Basu, P.; Goswami, A.; Kshetri, R.; Roy, Subinit; Chowdhury, P. Roy; Sarkar, M. Saha; Palit, R.; Parkar, V. V.; Santra, S.; Ray, M.

2011-01-01

Complete and incomplete fusion cross sections for 6 Li + 159 Tb have been measured at energies around the Coulomb barrier by the γ-ray method. The measurements show that the complete fusion cross sections at above-barrier energies are suppressed by ∼34% compared to coupled-channel calculations. A comparison of the complete fusion cross sections at above-barrier energies with the existing data for 11,10 B + 159 Tb and 7 Li + 159 Tb shows that the extent of suppression is correlated with the α separation energies of the projectiles. It has been argued that the Dy isotopes produced in the reaction 6 Li + 159 Tb at below-barrier energies are primarily due to the d transfer to unbound states of 159 Tb, while both transfer and incomplete fusion processes contribute at above-barrier energies.

Study of fission reactions induced by 4,6He and 7Li beams on 209Bi and 208Pb targets

Directory of Open Access Journals (Sweden)

Lukyanov S.M.

2013-12-01

Full Text Available Study of fission reactions induced by 4,6He and 7Li beams on 209Bi and 208Pb targets, leading to the production of 210,212A compound nuclei, was performed. It was shown that the fission excitation functions for the three reactions 4,6He + 209Bi and 7Li + 208Pb had similar behavior within the experimental error for a broad range of energy. More likely, halo structure of 6He is not reflected on the fission reaction mechanism. Otherwise, a large value of the fusion cross section was observed so far, as it could be expected in the case of weakly bound character of 6He projectile.

Enhanced ionic conductivity with Li{sub 7}O{sub 2}Br{sub 3} phase in Li{sub 3}OBr anti-perovskite solid electrolyte

Energy Technology Data Exchange (ETDEWEB)

Zhu, Jinlong, E-mail: jlzhu04@physics.unlv.edu, E-mail: yusheng.zhao@unlv.edu, E-mail: zhaoys@sustc.edu.cn; Li, Shuai; Zhang, Yi; Howard, John W.; Wang, Yonggang; Kumar, Ravhi S.; Wang, Liping [High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154 (United States); Lü, Xujie [Center for Integrated Nanotechnologies and Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Li, Yutao [Materials Research Program and The Texas Materials Institute, University of Texas at Austin, Texas 78712 (United States); Zhao, Yusheng, E-mail: jlzhu04@physics.unlv.edu, E-mail: yusheng.zhao@unlv.edu, E-mail: zhaoys@sustc.edu.cn [High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154 (United States); Department of Physics, South University of Science and Technology of China, Guangdong 518055 (China)

2016-09-05

Cubic anti-perovskites with general formula Li{sub 3}OX (X = Cl, Br, I) were recently reported as superionic conductors with the potential for use as solid electrolytes in all-solid-state lithium ion batteries. These electrolytes are nonflammable, low-cost, and suitable for thermoplastic processing. However, the primary obstacle of its practical implementation is the relatively low ionic conductivity at room temperature. In this work, we synthesized a composite material consisting of two anti-perovskite phases, namely, cubic Li{sub 3}OBr and layered Li{sub 7}O{sub 2}Br{sub 3,} by solid state reaction routes. The results indicate that with the phase fraction of Li{sub 7}O{sub 2}Br{sub 3} increasing to 44 wt. %, the ionic conductivity increased by more than one order of magnitude compared with pure phase Li{sub 3}OBr. Formation energy calculations revealed the meta-stable nature of Li{sub 7}O{sub 2}Br{sub 3}, which supports the great difficulty in producing phase-pure Li{sub 7}O{sub 2}Br{sub 3} at ambient pressure. Methods of obtaining phase-pure Li{sub 7}O{sub 2}Br{sub 3} will continue to be explored, including both high pressure and metathesis techniques.

Crystals structure of Na3Li(TiF6)2

International Nuclear Information System (INIS)

Popov, D.Yu.; Antokhina, T.F.; Gerasimenko, A.V.; Kajdalova, T.A.; Sergienko, V.I.

2004-01-01

Crystals of Na 3 Li(TiF 6 ) 2 (1) were synthesized in aqueous solution and characterized by the elementary and X-ray phase analysis methods. According to X-ray diffraction analysis data compound 1 is crystallized in a tetragonal crystal system with the following parameters: a=5.130(1), c=18.046(4) A, Z=2, space group P4-bar2 1 c. Alternating layers on the basis of dimers made up by octahedrons of TiF 6 and Na(1)F 6 constitute the frame of compound 1 crystal structure. The dimer layers are joined in a continuous frame by Na(2) and Li cations. Coordination polyhedron of Li atom is tetrahedron (Li-F 1.898(3) A) [ru

The real potential continuous ambiguity for 90 MeV Li ions

International Nuclear Information System (INIS)

Cook, J.; Barnwell, J.M.; Clarke, N.M.; Griffiths, R.J.

1980-01-01

The features of discrete and continuous ambiguities in the real phenomenological optical potential are clarified. The continuous ambiguity in the real potential for the scattering of 90 MeV 6 Li and 7 Li ions from 27 Al is investigated. For 6 Li the ambiguity is of Igo (Phys. Rev. Lett.; 1: 72 (1958) and Phys. Rev.; 115: 1665 (1959)) type but for 7 Li it is of Vrsup(n) = constant type. The implications of this are that 7 Li is less strongly absorbed than 6 Li. (author)

Ionic debye screening in dense liquid plasmas observed for Li+p, d reactions with liquid Li target

International Nuclear Information System (INIS)

Kasagi, J.; Yonemura, H.; Toriyabe, Y.; Nakagawa, A.; Sugawara, T.; Wang Tieshan

2009-01-01

Thick target yields of α particles emitted in the 6 Li(d,α) 4 He and 7 Li(p,α) 4 He reactions were measured for Li target in the solid and liquid phase. Observed reaction rates for the liquid Li are always larger than those for the solid. This suggests that the stopping power of hydrogen ion in the liquid Li metal might be smaller than in the solid. Using the empirically obtained stopping power for the liquid Li, we have deduced the screening potentials of the Li+p and Li+d reactions in both phases. The deduced screening potential for the liquid Li is about 500 eV larger than for the solid. This difference is attributed to the effect of liquefied Li + ions. It is concluded that the ionic screening is much stronger than the electronic screening in a low-temperature dense plasmas. (authors)

Ionic Debye Screening in Dense Liquid Plasmas Observed for Li+p,d Reactions with Liquid Li Target

Institute of Scientific and Technical Information of China (English)

J.Kasagi; H.Yonemura; Y.Toriyabe; A.Nakagawa; T.Sugawara; WANG Tie-shan

2009-01-01

Thick target yields of a particles emitted in the ~6Li(d,a)~4 He and ~7Li(p,a)~4 He reactions were measured for Li target in the solid and liquid phase.Observed reaction rates for the liquid Li are always larger than those for the solid.This suggests that the stopping power of hydrogen ion in the liquid Li metal might be smaller than in the solid.Using the empirically obtained stopping power for the liquid Li,we have deduced the screening potentials of the Li+p and Li+d reactions in both phases.The deduced screening potential for the liquid Li is about 500 eV larger than for the solid.This difference is attributed to the effect of liquefied Li~+ ions.It is concluded that the ionic screening is much stronger than the electronic screening in a low-temperature dense plasmas.

The total angular moment selectivity in 7Li(α, α) 7Li(4.63 MeV, 7/2-) reaction at Eα = 27.2 MeV

International Nuclear Information System (INIS)

Dmitrenko, V.N.; Kozyr', Yu.E.

1995-01-01

The DWBA calculation of tensor polarisation of residual nuclei for direct inelastic scattering 7 Li(α, α) 7 Li(4.63 MeV, 7/2 - ) gives the lest approximation to experimental data at selected total angular moment and parity values J π 13/2 + . The microscopic coupled channel calculation also predicts a significant role of total angular moment states with J ≥ 13/2. at E α 27.2 MeV

Synthesis and electrochemistry of cubic rocksalt Li-Ni-Ti-O compounds in the phase diagram of LiNiO{sub 2}-LiTiO{sub 2}-Li[Li{sub 1/3}Ti{sub 2/3}]O{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zhang, Lianqi; Noguchi, Hideyuki; Li, Decheng; Muta, Takahisa; Wang, Xiaoqing; Yoshio, Masaki [Department of Applied Chemistry, Saga University, Saga 840-8052 (Japan); Taniguchi, Izumi [Department of Chemical Engineering, Tokyo Institute of Technology, 12-1, Ookayama-2, Meguro-ku, Tokyo 152-8552 (Japan)

2008-10-15

On the basis of extreme similarity between the triangle phase diagrams of LiNiO{sub 2}-LiTiO{sub 2}-Li[Li{sub 1/3}Ti{sub 2/3}]O{sub 2} and LiNiO{sub 2}-LiMnO{sub 2}-Li[Li{sub 1/3}Mn{sub 2/3}]O{sub 2}, new Li-Ni-Ti-O series with a nominal composition of Li{sub 1+z/3}Ni{sub 1/2-z/2}Ti{sub 1/2+z/6}O{sub 2} (0 {<=} z {<=} 0.5) was designed and attempted to prepare via a spray-drying method. XRD identified that new Li-Ni-Ti-O compounds had cubic rocksalt structure, in which Li, Ni and Ti were evenly distributed on the octahedral sites in cubic closely packed lattice of oxygen ions. They can be considered as the solid solution between cubic LiNi{sub 1/2}Ti{sub 1/2}O{sub 2} and Li[Li{sub 1/3}Ti{sub 2/3}]O{sub 2} (high temperature form). Charge-discharge tests showed that Li-Ni-Ti-O compounds with appropriate compositions could display a considerable capacity (more than 80 mAh g{sup -1} for 0.2 {<=} z {<=} 0.27) at room temperature in the voltage range of 4.5-2.5 V and good electrochemical properties within respect to capacity (more than 150 mAh g{sup -1} for 0 {<=} z {<=} 0.27), cycleability and rate capability at an elevated temperature of 50 C. These suggest that the disordered cubic structure in some cases may function as a good host structure for intercalation/deintercalation of Li{sup +}. A preliminary electrochemical comparison between Li{sub 1+z/3}Ni{sub 1/2-z/2}Ti{sub 1/2+z/6}O{sub 2} (0 {<=} z {<=} 0.5) and Li{sub 6/5}Ni{sub 2/5}Ti{sub 2/5}O{sub 2} indicated that charge-discharge mechanism based on Ni redox at the voltage of >3.0 V behaved somewhat differently, that is, Ni could be reduced to +2 in Li{sub 1+z/3}Ni{sub 1/2-z/2}Ti{sub 1/2+z/6}O{sub 2} while +3 in Li{sub 6/5}Ni{sub 2/5}Ti{sub 2/5}O{sub 2}. Reduction of Ti{sup 4+} at a plateau of around 2.3 V could be clearly detected in Li{sub 1+z/3}Ni{sub 1/2-z/2}Ti{sub 1/2+z/6}O{sub 2} with 0.27 {<=} z {<=} 0.5 at 50 C after a deep charge associated with charge compensation from oxygen ion during initial cycle

Electrochemical Behavior of LiBr, LiI, and Li2Se in LiCl Molten Salt

International Nuclear Information System (INIS)

Choi, In Kyu; Do, Jae Bum; Hong, Sun Seok; Seo, Chung Seok

2006-03-01

The effect of fission products on the electrolytic reduction of uranium oxide has been studied. It has been reported that volatile fission products, such as Br, I, and Se, react with Li metal which is a reductant in the process to give LiBr, LiI, and Li 2 Se. These compounds are dissociated as corresponding anions and cations in the LiCl molten salt at 650 .deg. C. In this experiment, oxidation and reduction reaction of 3wt% of each compound in LiCl molten salt were investigated by cyclic voltammetry. For LiBr, redox reactions of cation and anion were reversible, while redox reactions of Li + and I - were irreversible. For Li 2 Se, about half of the produced Li metal was disappeared at the cathode and two anodic current curves were appeared. After the cyclic voltammetric measurements for each compound, chronopotentiometric experiment was carried out for one hour with 100 - 400 mA. After the electrolysis, no compounds gave Li metal in the porous MgO filter in which Li metal was produced at the cathode. However, LiCl salt was covered with Br 2 for LiBr electrolysis. Dark red color of Br 2 was easily removed by water. For LiI electrolysis, salt gave black color and I 2 was deposited on the Pt anode. For Li 2 Se electrolysis, black fine powders were precipitated in the salt. After the separation and dryness of the precipitates, it was analyzed with XRD and it turned out PtSe 2 . From the electrochemical experimental results, it was concluded that these compounds may affect the electrolytic reduction process of uranium oxide in the spent fuel

CuLi2Sn and Cu2LiSn: Characterization by single crystal XRD and structural discussion towards new anode materials for Li-ion batteries.

Science.gov (United States)

Fürtauer, Siegfried; Effenberger, Herta S; Flandorfer, Hans

2014-12-01

The stannides CuLi 2 Sn (CSD-427095) and Cu 2 LiSn (CSD-427096) were synthesized by induction melting of the pure elements and annealing at 400 °C. The phases were reinvestigated by X-ray powder and single-crystal X-ray diffractometry. Within both crystal structures the ordered CuSn and Cu 2 Sn lattices form channels which host Cu and Li atoms at partly mixed occupied positions exhibiting extensive vacancies. For CuLi 2 Sn, the space group F-43m. was verified (structure type CuHg 2 Ti; a =6.295(2) Å; wR 2 ( F ²)=0.0355 for 78 unique reflections). The 4( c ) and 4( d ) positions are occupied by Cu atoms and Cu+Li atoms, respectively. For Cu 2 LiSn, the space group P 6 3 / mmc was confirmed (structure type InPt 2 Gd; a =4.3022(15) Å, c =7.618(3) Å; wR 2 ( F ²)=0.060 for 199 unique reflections). The Cu and Li atoms exhibit extensive disorder; they are distributed over the partly occupied positions 2( a ), 2( b ) and 4( e ). Both phases seem to be interesting in terms of application of Cu-Sn alloys as anode materials for Li-ion batteries.

Modeling Li-ion conductivity in LiLa(PO{sub 3}){sub 4} powder

Energy Technology Data Exchange (ETDEWEB)

Mounir, Ferhi, E-mail: ferhi.mounir@gmail.com [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia); Karima, Horchani-Naifer [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia); Khaled, Ben Saad [Laboratoire de Photovoltaieque, Centre des Recherches et des Technologies de l' Energie, Technopole Borj Cedria, BP No. 95, 2050 Hammam Lif (Tunisia); Mokhtar, Ferid [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia)

2012-07-01

Polycrystalline powder and single-crystal of LiLa(PO{sub 3}){sub 4} are synthesized by solid state reaction and flux technique, respectively. A morphological description of the obtained product was made based on scanning electron microscopy micrographs. The obtained powder was characterized by X-ray powder diffraction, FTIR and Raman spectroscopies. Ionic conductivity of the LiLa(PO{sub 3}){sub 4} powder was measured and evaluated over a temperature range from 553 to 913 K. Single crystals of LiLa(PO{sub 3}){sub 4} are characterized by single-crystal X-ray diffraction. The LiLa(PO{sub 3}){sub 4} structure was found to be isotypic with LiNd(PO{sub 3}){sub 4}. It crystallizes in the monoclinic system with space group C2/c and cell parameters: a=16.635(6) A, b=7.130(3) A, c=9.913(3) A, {beta}=126.37(4) Degree-Sign , V=946.72(6) A{sup 3} and Z=4. The LiLa(PO{sub 3}){sub 4} structure was described as an alternation between spiraling chains (PO{sub 3}){sub n} and (La{sup 3+}, Li{sup +}) cations along the b direction. The small Li{sup +} ions, coordinated to four oxygen atoms, were located in the large connected cavities created between the LaO{sub 8} polyhedra and the polyphosphate chains. The jumping of Li{sup +} through tunnels of the crystalline network was investigated using complex impedance spectroscopy. The close value of the activation energies calculated through the analysis of conductivity data and loss spectra indicate that the transport in the investigated system is through hopping mechanism. The correlation between ionic conductivity of LiLa(PO{sub 3}){sub 4} and its crystallographic structure was investigated and the most probably transport pathway model was determined.

Measurement of 6Li(n,α)3H reaction cross section

International Nuclear Information System (INIS)

Renner, C.

1979-01-01

The 6 Li(n,α) 3 H reaction cross section was measured at 12 discrete neutron energies between 80 KeV and 470 KeV by using the Oak Ridge Linear Acelerator (ORELA) as a pulsed neutron source. The neutron beam was filtered through 20 cm or 30 cm of Armco iron which produces several monoenergetic energies groups (iron windows) between 20 KeV and 1000 KeV about 2 KeV wide. The (n,α) events were detected by a 1 mm thick Li-glass scintillator and the neutron flux was measured with a NE110 plastic scintillator 6,6 cm thick and 10 cm in diameter. Multiple scattering corrections in the Li-glass and the NE110 scintillator efficiency were determined theoretically by using Monte Carlo technique. The 6 Li content in the Li-glasses was determined by transmission measurements with low energy neutrons. A theoretical fit was applied to the results by the R-matrix theory. (Author) [pt

Synthesis of high-purity Li{sub 8}ZrO{sub 6} powder by solid state reaction under hydrogen atmosphere

Energy Technology Data Exchange (ETDEWEB)

Shin-mura, Kiyoto; Otani, Yu; Ogawa, Seiya [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Niwa, Eiki; Hashimoto, Takuya [Department of Physics, College of Humanities and Sciences, Nihon University, 3-8-1 Sakurajousui, Setagaya-ku, Tokyo 156-8550 (Japan); Hoshino, Tsuyoshi [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuchi, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Sasaki, Kazuya, E-mail: k_sasaki@tokai-u.ac.jp [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Department of Prime Mover Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)

2016-11-01

Highlights: • A fine pure Li{sub 8}ZrO{sub 6} powder was synthesized by using Li{sub 2}CO{sub 3} and ZrO{sub 2} via a solid state reaction. • Influences on the purity of product powder, lattice defect, and crystal orientation were revealed. • The suitable synthesis conditions of the fine and high purity Li{sub 8}ZrO{sub 6} powder were found. • The reaction process of the synthesis of Li{sub 8}ZrO{sub 6} was estimated. - Abstract: Li{sub 8}ZrO{sub 6} contains a large amount of Li and has a significant potential as a tritium breeder. However, few syntheses of fine-grain, high-purity Li{sub 8}ZrO{sub 6} powder have been reported. In this study, a high-purity powder of Li{sub 8}ZrO{sub 6} was synthesized by solid state reaction under hydrogen atmosphere combined with an effective lithium source and a suitable initial Li:Zr molar ratio. Mixed powders of Li{sub 2}CO{sub 3} and ZrO{sub 2} were fired at around 630 °C in H{sub 2} for several hours and several firing cycles. The low firing temperature inhibited the vaporization of Li during the heating, so that excessive amounts of Li were not needed for the synthesis, and the Li:Zr ratio in the starting material was 10:1 (mol:mol). In this synthesis, Li{sub 2}O was generated via the decomposition of Li{sub 2}CO{sub 3} during firing in H{sub 2}, and reacted with ZrO{sub 2} to form Li{sub 6}Zr{sub 2}O{sub 7}, which reacted with itself to form Li{sub 8}ZrO{sub 6}.

Synthesis and structure of ternary lithium, calcium, copper phosphate Ca9CuLi(PO4)7

International Nuclear Information System (INIS)

Yanov, O.V.; Morozov, V.A.; Koznyakov, I.V.; Lazoryak, B.I.; Khasanov, S.S.

1998-01-01

New Ca 9 CuLi(PO 4 ) 7 compound is synthesized and specified through the methods of roentgenographic and thermogravimetric analysis. This compound is crystallized in trigonal syngony (sp.gr. R3c, Z=6) and is related to the structural type of the vitlokite natural mineral. The crystal structure (a=10.3231(2), c=37.111(1)A, V=3425(2)A 3 , R WP =5.99, R p =4/35, R I =2.25, R F =1.11, R E =3.28) is verified through the Ritweld method. The calcium cations are positioned in three nonequivalent octaapexed. The copper cations are located in a distorted octahedron. The lithium cations occupy irregularly and statistically two types of positions Li(A) (75(6)%) and Li(B) (25(6)%)uLi(PO 4 ) 7

ANC of 6.92 MeV (2"+) and 7.12 MeV (1"-) states from sub-Coulomb "1"2C("6Li,d) data

International Nuclear Information System (INIS)

Mondal, Ashok; Basu, C.; Adhikari, S.

2016-01-01

The determination of the astrophysical S-factor of the "1"2C(α,γ) reaction at 300 keV requires a R-matrix extrapolation. This is because a direct measurement of this reaction at 300 keV is almost impossible due to the very small cross-section. The R-matrix extrapolation requires as input the asymptotic normalization constant (ANC) of mainly two "1"6O states states viz. 6.92 MeV and 7.12 MeV on which the fit is most sensitive. The ANC of these two states have been determined from indirect measurements, mainly from "1"2C("6Li,d) and "1"2C("7Li,t) alpha transfer reactions. Most of these measurements are done at above barrier energies as cross-sections are larger. In this work, we determine the ANC of the 6.92 MeV and 7.12 MeV states of "1"6O using the "1"2C("6Li,d) data of Heikkinen et al measured at 4.5 to 5.0 MeV incident energies. The data spans over a larger angular span in comparison to Avila though the former data do not cover the very backward angles as in the Avila data. As the Heikkinen data has never been analyzed to extract the ANC we report the results of our analysis of the data

The puzzle of the 6Li quadrupole moment: steps toward the solution

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Kukulin, V.I.; Pomerantsev, V.N.

2005-01-01

The problem of origin of the ground-state 6 Li quadrupole deformation has been investigated with account of the three-deuteron component of this nucleus wave function. two long-standing puzzles related to the tensor interaction in 6 Li are known. The first one lies in the anomalously small value of the 6 Li quadrupole moment which, being negative, is in absolute magnitude smaller by the factor of 5 than that of 6 Li. The second puzzle consists in the anomalous behavior of the tensor analyzing power T 2q in scattering of polarized 6 Li nuclei from various targets. It is shown that the large (in absolute magnitude) negative contribution to the 6 Li quadrupole moment resulting from the three-deuteron configuration cancels almost completely the direct positive contribution due to the folding αd-potential. As a result, the total quadrupole moment turns out to be close to zero and highly sensitive to fine details of the tensor NN interaction and of the 4 He wave function [ru

Magnetic properties and phase transitions in LiCu_2O2 by ^7Li NMR

Science.gov (United States)

Caldwell, Tod; Moulton, William G.; Reyes, Arneil P.; Kuhns, Phillip L.; Cao, Gang; Xin, Yiu; Crow, Jack E.

2001-03-01

LiCu_2O2 is a compound with double chain Cu^2+ copper ions separated in pairs by Li and Cu^1+ that forms a spin ladder or zig-zag chain system depending on the relative J's. The orthorhombic single crystals are highly twinned as determined by TEM. Magnetization and specific heat show ladder behavior above a transition near 25 K, suggestive of a first order transition from specific heat data. ^7Li NMR spectra show a 0.16%,(c-axis)nearly temperature independent shift above the transition, and is nearly an order of magnitude smaller perpendicular, with a dramatic increase at 24.3 K. At 24.3 the spectrum broadens and splits into 6 (not fully resolved) lines, maximum splitting 0.2 T, clearly indicating the presence of a static internal field due to some AF spin arrangement. The splitting is temperature independent below 23 K, unusual for an AF.The large shift of the spectrum center below the transition may indicate large spin fluctuations. No evidence of a second transition at 9 K observed in the specific heat and magnetization are found in the NMR data. The results for the quadrupole parameters and the possible spin configurations will be presented.

Incomplete fusion analysis of the 7Li-induced reaction on 93Nb within 3-6.5 MeV/nucleon

Science.gov (United States)

Kumar, Deepak; Maiti, Moumita

2017-10-01

Background: It is understood from the recent experimental studies that prompt/resonant breakup, and transfer followed by breakup in the weakly bound Li,76-induced reactions play a significant role in the complete-incomplete fusion (CF-ICF), suppression/enhancement in the fusion cross section around the Coulomb barrier. Purpose: Investigation of ICF over CF by measuring cross sections of the populated residues, produced via different channels in the 7Li-induced reaction on a natNb target within the 3-6.5 MeV/nucleon energy region. Method: The 7Li beam was allowed to hit the self-supporting 93Nb targets, backed by the aluminium (Al) foil alternately, within 3-6.5 MeV/nucleon energy. Populated residues were identified by offline γ -ray spectrometry. Measured excitation functions of different channels were compared with different equilibrium and pre-equilibrium models. Result: The enhancement in cross sections in the proton (˜20 -30 MeV) and α -emitting channels, which may be ascribed to ICF, was observed in the measured energy range when compared to the Hauser-Feshbach and exciton model calculations using empire, which satisfactorily reproduces the neutron channels, compared to the Weisskopf-Ewing model and hybrid Monte Carlo calculations. The increment of the incomplete fusion fraction was observed with rising projectile energy. Conclusion: Contrary to the alice14, experimental results are well reproduced by the empire throughout the measured energy range. The signature of ICF over CF indicates that the breakup/transfer processes are involved in the weakly bound 7Li-induced reaction on 93Nb slightly above the Coulomb barrier.

Magnetic properties of lithium rare-earth fluorides: Ferromagnetism in LiErF4 and LiHoF4 and crystal-field parameters at the rare-earth and Li sites

DEFF Research Database (Denmark)

Hansen, P. E.; Johansson, Torben; Nevald, Rolf

1975-01-01

Single crystals of LiErF4 and LiHoF4 have been grown and their magnetic properties measured from 1.3 K to 300 K. LiHoF4 turned out to be a nearly ideal Ising ferromagnet with TC=1.30±0.05 K and a saturation magnetization along the crystalline c axis of (6.98±0.02)μB. In LiErF4 no ordering...... was observed, but extrapolation indicates that below 0.5 K it will be ferromagnetic with the magnetic moments in the crytalline ab plane. From the susceptibilities the crystal-field parameters Bnm with (n, m)=(2, 0), (4, 0), (4, 4), (6, 0), (6, 4) have been extracted giving for Er3+ in LiErF4: 430., -985......., 1185., -5., 740.+i135. (cm-1) and for Ho3+ in LiHoF4: 470., -825., 1050., -10., 760.+i150 (cm-1). The exchange constants were found to be small compared to the dipole interactions. Furthermore the 7Li NMR spectra have been obtained in these materials as well as in LiTbF4 thereby determining the second...

Li Isotope Studies of Olivine in Mantle Xenoliths by SIMS

Science.gov (United States)

Bell, D. R.; Hervig, R. L.; Buseck, P. R.

2005-01-01

Variations in the ratio of the stable isotopes of Li are a potentially powerful tracer of processes in planetary and nebular environments [1]. Large differences in the 7Li/6Li ratio between the terrestrial upper mantle and various crustal materials make Li isotope composition a potentially powerful tracer of crustal recycling processes on Earth [2]. Recent SIMS studies of terrestrial mantle and Martian meteorite samples report intra-mineral Li isotope zoning [3-5]. Substantial Li isotope heterogeneity also exists within and between the components of chondritic meteorites [6,7]. Experimental studies of Li diffusion suggest the potential for rapid isotope exchange at elevated temperatures [8]. Large variations in 7Li, exceeding the range of unaltered basalts, occur in terrestrial mantle-derived xenoliths from individual localities [9]. The origins of these variations are not fully understood.

Electrochemical and diffusional insights of combustion synthesized SrLi2Ti6O14 negative insertion material for Li-ion Batteries

Science.gov (United States)

Dayamani, Allumolu; Shinde, Ganesh S.; Chaupatnaik, Anshuman; Rao, R. Prasada; Adams, Stefan; Barpanda, Prabeer

2018-05-01

Solvothermal synthetic routes can provide energy-savvy platforms to fabricate battery anode materials involving relatively milder annealing steps vis-à-vis the conventional solid-state synthesis. These energy efficient routes in turn restrict aggressive grain growth to form nanoscale particles favouring efficient Li+ diffusion. Here, we report an economic solution combustion synthesis of SrLi2Ti6O14 anode involving nitrate-urea complexation with a short annealing duration of only 2 h (900 °C). Rietveld refinement confirms the phase purity of target product assuming an orthorhombic framework (Cmca symmetry). It delivers reversible capacity of ∼125 mAh.g-1 at a rate of C/20 involving a 1.38 V Ti4+/Ti3+ redox activity with excellent rate kinetics and cycling stability. Bond valence site energy (BVSE) calculations gauge SrLi2Ti6O14 to be an anisotropic 3D Li+ ion conductor with the highest ionic conductivity along the c direction. The electrochemical and diffusional pathways have been elucidated for combustion prepared SrLi2Ti6O14 as an efficient and safe negative electrode candidate for Li-ion batteries.

Characterization of the thermoluminescent detectors LiF:Mg,Cu,P. Environmental dosimetry applications

International Nuclear Information System (INIS)

Ciocci Brazzano, Ligia; Gregori, Beatriz N.; Papadopulos, Susana B.; Carelli, Jorge L.

2005-01-01

Studies on thermal-luminescent properties of the LiF:Mg detectors, Cu, P enrichment with Li-7 (99.93% of Li-7 and 0.07% of Li-6): optimization of the heating profile, loss of information, detection limit and doses and energy responses are presented in this work. Their performance is compared with LiF:Mg detectors, Mg, Ti enriched with Li-7 (99.93% of Li-7 and 0.07% Li-6), which are at present used for environmental dosimetry at the Physics Dosimetry Laboratory of the Nuclear Regulatory Authority [es

Fusion spectrum neutron source computation in "6LiD convertor for HFETR

International Nuclear Information System (INIS)

Sun Shouhua; Hu Yifei; Ye Bin

2014-01-01

A computation model of 14 MeV neutron from the "6LiD convertor has been established, the 14 MeV neutron sources and flux in the irradiation samples from the "6LiD convertor and the core have been computed separately, the neutron spectrum in the irradiation samples have been computed, too. The results show that the neutron sources that over 13 MeV account for 1 MeV above in the "6LiD convertor is 25.7%, 24.6% respectively, 14 MeV neutron sources get 4.31 × 10"1"3 n_T·s"-"1, 3.34 × 10"1"3 n_T·s"-"1, 14 MeV neutron flux get 2.66 × 10"1"0 n_T·cm"-"2·s"-"1, 3.53 × 10"1"0 n_T·cm"-"2·s"-"1, as He and H_2O charged in the irradiation capsule. (authors)

A novel dual-salts of LiTFSI and LiODFB in LiFePO4-based batteries for suppressing aluminum corrosion and improving cycling stability

Science.gov (United States)

Li, Faqiang; Gong, Yan; Jia, Guofeng; Wang, Qinglei; Peng, Zhengjun; Fan, Wei; Bai, Bing

2015-11-01

The strong corrosion behavior at the Al current collector restricts the application range of lithium bis (trifluoromethanesulfonylimide) (LiTFSI), despite its high stability against water and thermal. SEM, LSV and Tafel curves proved that adding LiODFB into LiTFSI-based electrolytes could suppress aluminum corrosion caused by LiTFSI-based electrolytes. The cycling stability and rate capability of LiFePO4-based batteries using LiTFSI0.6-LiODFB0.4-based electrolytes is excellent as compared to LiFePO4-based batteries using LiPF6-based electrolytes.

Two-proton pickup studies with the (6Li,8B) reaction

Energy Technology Data Exchange (ETDEWEB)

Weisenmiller, R.B.

1976-12-03

The (/sup 6/Li,/sup 8/B) reaction has been investigated on targets of /sup 26/Mg, /sup 24/Mg, /sup 16/O, /sup 13/C, /sup 12/C, /sup 11/B, /sup 10/B, and /sup 9/Be at a bombarding energy of 80.0 MeV, and on targets of /sup 16/O, /sup 12/C, /sup 9/Be, /sup 7/Li, and /sup 6/Li at a bombarding energy of 93.3 MeV. Only levels consistent with direct, single-step two-proton pickup reaction mechanisms were observed to be strongly populated. On T/sub z/ = 0 targets, the spectroscopic selectivity of this reaction resembles that of the analogous (p,t) reaction. Additionally, these data demonstrate the dominance of spatially symmetric transfer of the two protons. On T/sub z/ greater than 0 targets the (/sup 6/Li,/sup 8/B) reaction was employed to locate two previously unreported levels (at 7.47 +- 0.05 MeV and 8.86 +- 0.07 MeV) in the T/sub z/ = 2 nuclide /sup 24/Ne and to establish the low-lying 1p-shell states in the T/sub z/ = /sup 3///sub 2/ nuclei /sup 11/Be, /sup 9/Li, and /sup 7/He. However, no evidence was seen for any narrow levels in the T/sub z/ = /sup 3///sub 2/ nuclide /sup 5/H nor for any narrow excited states in /sup 7/He. The angular distributions reported here are rather featureless and decrease monotonically with increasing angle. This behavior can be shown by a semi-classical reaction theory to be a consequence of the reaction kinematics. A semi-classical approach also suggests that the kinematic term in the transition matrix element is only weakly dependent upon the angular momentum transfer (which is consistent with simple Distorted Wave Born Approximation calculations). However, only qualitative agreement was obtained between the observed relative transition yields and semi-classical predictions, using the two-nucleon coefficients of fractional parentage of Cohen and Kurath, probably due to the limitations of the semi-classical reaction theory.

The Li–Si–(O)–N system revisited: Structural characterization of Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O

Energy Technology Data Exchange (ETDEWEB)

Casas-Cabanas, M. [CIC energiGUNE, Parque Tecnológico de Álava, Albert Einstein 48, ED.CIC, 01510 Miñano (Spain); Santner, H. [Institut de Ciència de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Catalonia (Spain); Palacín, M.R., E-mail: rosa.palacin@icmab.es [Institut de Ciència de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Catalonia (Spain)

2014-05-01

A systematic study of the Li–Si–(O)–N system is presented. The synthetic conditions to prepare Li{sub 2}SiN{sub 2}, Li{sub 5}SiN{sub 3}, Li{sub 18}Si{sub 3}N{sub 10}, Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O are described and the structure of the last two compounds has been solved for the first time. While Li{sub 21}Si{sub 3}N{sub 11} crystallizes as a superstructure of the anti-fluorite structure with Li and Si ordering, Li{sub 7}SiN{sub 3}O exhibits the anti-fluorite structure with both anion and cation disorder. - Graphical abstract: A systematic study of the Li–Si–(O)–N system is presented. Li{sub 21}Si{sub 3}N{sub 11} crystallizes as a superstructure of the anti-fluorite structure with Li and Si ordering, Li{sub 7}SiN{sub 3}O exhibits the anti-fluorite structure with both anion and cation disorder. - Highlights: • Li{sub 2}SiN{sub 2}, Li{sub 5}SiN{sub 3}, Li{sub 18}Si{sub 3}N{sub 10}, Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O are prepared. • The structures of Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O are presented. • Li{sub 21}Si{sub 3}N{sub 11} exhibits an anti-fluorite superstructure with Li and Si ordering.

LiPF{sub 6}. Synthesis and stability in EC/DMC and PC/DMC mixtures; LiPF{sub 6}. Synthese et stabilite dans les melanges EC/DMC et PC/DMC

Energy Technology Data Exchange (ETDEWEB)

Naejus, R.; Coudert, R.; Lemordant, D. [Laboratoire P.I.M.I.R. EA, Sciences et Techniques, 37 - Tours (France); Willmann, P. [CNES, 31 - Toulouse (France)

1996-12-31

Lithium hexa-fluoro-phosphate LiPF{sub 6} is recommended for the replacement of the toxic LiAsF{sub 6} and the explosive perchlorates (like LiClO{sub 4}) in rechargeable lithium electrochemical generators. The aim of this work is to develop a new method of synthesis of this salt and to check its stability with respect to carbonated solvents: ethylene carbonate (EC), propylene carbonate (PC) and dimethyl-carbonate (DMC) in already optimized EC/DMC and PC/DMC binary mixtures. Two methods using HPF{sub 6} are proposed: the first one uses the direct neutralization of this commercial acid by LiOH in aqueous, alcoholic or acetonitrile environment, while in the second one LiPF{sub 6} is obtained from pyridinium hexa-fluoro-phosphate synthesized from HPF{sub 6} using a new and simple protocol. (J.S.) 24 refs.

LiPF{sub 6}. Synthesis and stability in EC/DMC and PC/DMC mixtures; LiPF{sub 6}. Synthese et stabilite dans les melanges EC/DMC et PC/DMC

Energy Technology Data Exchange (ETDEWEB)

Naejus, R; Coudert, R; Lemordant, D [Laboratoire P.I.M.I.R. EA, Sciences et Techniques, 37 - Tours (France); Willmann, P [CNES, 31 - Toulouse (France)

1997-12-31

Lithium hexa-fluoro-phosphate LiPF{sub 6} is recommended for the replacement of the toxic LiAsF{sub 6} and the explosive perchlorates (like LiClO{sub 4}) in rechargeable lithium electrochemical generators. The aim of this work is to develop a new method of synthesis of this salt and to check its stability with respect to carbonated solvents: ethylene carbonate (EC), propylene carbonate (PC) and dimethyl-carbonate (DMC) in already optimized EC/DMC and PC/DMC binary mixtures. Two methods using HPF{sub 6} are proposed: the first one uses the direct neutralization of this commercial acid by LiOH in aqueous, alcoholic or acetonitrile environment, while in the second one LiPF{sub 6} is obtained from pyridinium hexa-fluoro-phosphate synthesized from HPF{sub 6} using a new and simple protocol. (J.S.) 24 refs.

High-pressure X-ray study of LiCrSi₂O₆ clinopyroxene and the general compressibility trends of Li-clinopyroxenes

DEFF Research Database (Denmark)

Periotto, Benedetta; Angel, Ross J.; Nestola, Fabrizio

2013-01-01

High-pressure single-crystal X-ray diffraction measurements of synthetic LiCrSi2O6 clinopyroxene (with space group P21/c) were performed in a diamond-anvil cell up to 7.970 GPa. No phase transition has been observed within the pressure range investigated, but the elastic behavior at lower pressures...... phase transition above 8 GPa to the HP-C2/c space group. A comparison of the Li-clinopyroxenes (M1 = Cr, Al, Sc, Ga, Mg + Fe) previously investigated and our sample shows that their elastic behavior and structural mechanisms of compression are analogous....... derivative K0 = 8.8(6). The structural data measured up to 7.970 GPa confirm that the space group P21/c is maintained throughout the whole pressure range investigated. The atomic parameters, obtained from the integrated diffraction intensities, suggest that the Li coordination polyhedron changes its...

The 208Pb(7Li,6He)209Bi reaction at 52 MeV

International Nuclear Information System (INIS)

Zeller, A.F.; Weisser, D.C.; Ophel, T.R.; Hebbard, D.F.

1979-11-01

Single proton transfers to low lying levels in 209 Bi from the 208 Pb(7Li, 6 He) reaction at 52 MeV have been measured and spectroscopic factors derived from an EFR-DWBA analysis. Relative spectroscopic factors are in good agreement with light ion results and previous heavy ion work. Absolute spectroscopic factors were generally too large and the peaks of the angular distributions were out of phase with the DWBA calculations by 1 0 - 4 0

NUCLEON POLARIZATION IN 3-BODY MODELS OF POLARIZED LI-6

NARCIS (Netherlands)

SCHELLINGERHOUT, NW; KOK, LP; COON, SA; ADAM, RM

1993-01-01

Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

Li4FeH6: Iron-containing complex hydride with high gravimetric hydrogen density

Directory of Open Access Journals (Sweden)

Hiroyuki Saitoh

2014-07-01

Full Text Available Li4FeH6, which has the highest gravimetric hydrogen density of iron-containing complex hydrides reported so far, is synthesized by hydrogenation of a powder mixture of iron and LiH above 6.1 GPa at 900 °C. In situ synchrotron radiation X-ray diffraction measurements reveal that while kinetics require high temperature and thus high pressure for the synthesis, Li4FeH6 is expected to be thermodynamically stable slightly below room temperature at ambient pressure; further synthetic studies to suppress the kinetic effects may enable us to synthesize Li4FeH6 at moderate pressures. Li4FeH6 can be recovered at ambient conditions where Li4FeH6 is metastable.

The importance of the tensor interaction in the (7Li, 7Be) reaction

International Nuclear Information System (INIS)

Dodd, A.C.; Clarke, N.M.; Coopersmith, J.; Griffiths, R.J.; Pearce, K.I.; Stanley, B.; Cook, J.

1985-01-01

Data for the 28 Si( 7 Li, 7 Be) 28 Al reaction at 72 MeV and for the 26 Mg( 7 Li, 7 Be) 26 Na reaction at 88 MeV are presented together with one-step DWBA calculations using microscopic form factors. The tensor interaction is shown to be important to explain the structureless nature of the angular distributions. (author)

Electrochemical performances of LiMnPO4 synthesized from non-stoichiometric Li/Mn ratio.

Science.gov (United States)

Xiao, Jie; Chernova, Natasha A; Upreti, Shailesh; Chen, Xilin; Li, Zheng; Deng, Zhiqun; Choi, Daiwon; Xu, Wu; Nie, Zimin; Graff, Gordon L; Liu, Jun; Whittingham, M Stanley; Zhang, Ji-Guang

2011-10-28

In this paper, the influences of the lithium content in the starting materials on the final performances of as-prepared Li(x)MnPO(4) (x hereafter represents the starting Li content in the synthesis step which does not necessarily mean that Li(x)MnPO(4) is a single phase solid solution in this work.) are systematically investigated. It has been revealed that Mn(2)P(2)O(7) is the main impurity when Li Li(3)PO(4) begins to form once x > 1.0. The interactions between Mn(2)P(2)O(7) or Li(3)PO(4) impurities and LiMnPO(4) are studied in terms of the structural, electrochemical, and magnetic properties. At a slow rate of C/50, the reversible capacity of both Li(0.5)MnPO(4) and Li(0.8)MnPO(4) increases with cycling. This indicates a gradual activation of more sites to accommodate a reversible diffusion of Li(+) ions that may be related to the interaction between Mn(2)P(2)O(7) and LiMnPO(4) nanoparticles. Among all of the different compositions, Li(1.1)MnPO(4) exhibits the most stable cycling ability probably because of the existence of a trace amount of Li(3)PO(4) impurity that functions as a solid-state electrolyte on the surface. The magnetic properties and X-ray absorption spectroscopy (XAS) of the MnPO(4)·H(2)O precursor, pure and carbon-coated Li(x)MnPO(4) are also investigated to identify the key steps involved in preparing a high-performance LiMnPO(4). This journal is © the Owner Societies 2011

Scintillation properties of LiF–SrF2 and LiF–CaF2 eutectic

International Nuclear Information System (INIS)

Yanagida, Takayuki; Kawaguchi, Noriaki; Fujimoto, Yutaka; Fukuda, Kentaro; Watanabe, Kenichi; Yamazaki, Atsushi; Uritani, Akira

2013-01-01

Dopant free eutectic scintillators 6 LiF–SrF 2 and 6 LiF–CaF 2 were developed by the vertical Bridgeman method for the purpose of thermal neutron detection. The molar ratio of LiF and Ca/SrF 2 was 4:1 on its eutectic composition. The α-ray induced radioluminescence spectra of the scintillators showed intense emission peak at 300 nm due to the emission from the self-trapped exciton in Ca/SrF 2 layers. When the samples were irradiated with 252 Cf neutrons, 6 LiF–SrF 2 and 6 LiF–CaF 2 exhibited the light yields of 4700 and 9400 ph/n, respectively. Scintillation decay times of 6 LiF–SrF 2 and 6 LiF–CaF 2 were accepted for scintillation detectors, 90 and 250 ns, respectively. -- Highlights: • Nondoped LiF–CaF 2 and LiF–SrF 2 eutectic scinitillators are reported for the first time. • Two sample showed self-trapped exciton emission. • LiF–SrF 2 sample exhibited the light yield of 9400 ph/n and this value was comparable to conventional materials doped with rare earth ions. • Scintillation decay times of LiF–CaF 2 and LiF–SrF 2 were 250 and 90 ns, respectively

Neutron spatial distribution measurement with 6Li-contained thermoluminescent sheets

International Nuclear Information System (INIS)

Konnai, A.; Odano, N.; Sawamura, H.; Ozasa, N.; Ishikawa, Y.

2006-01-01

We have been developing a thermoluminescent (TL) sheet for photon dosimetry (TL sheet) with thermoluminescent material of LiF:Mg, Cu, P and a co-polymer of ethylene and tetrafluoroethylene. For the purpose of a development of simple method for neutron spatial distribution measurement, TL sheet for neutron detection (NTL sheet) is made by adding 94.7% enriched 6 LiF to TL sheet. TL material in TL sheet is directly excited by ionizing radiation whereas, in the case of neutron detection, TL material in NTL sheet is indirectly excited by neutron capture reaction. That is neutron distribution can be obtained with TL caused by α particle from 6 Li(n, α) 3 H reaction. Responses of NTL sheets to neutrons were examined at the neutron beam irradiation facility for Boron Neutron Capture Therapy (BNCT) in JRR-4 research reactor in Japan Atomic Energy Agency. TL and NTL sheets were exposed to striped and roundly distributed neutron fields. Attenuations of neutron flux in air and water were also observed using NTL sheets. TL sheets were also exposed on the same conditions and compared with NTL sheets. TL intensity ratios of NTL sheet to TL sheet were consistent with the calculated value from 6 Li content. Thermal neutron attenuation observed by NTL sheet also corresponded with the result measured by Au wire radioactivation and TLD chips, which were currently used in BNCT at JRR-4. These results were analyzed with by Monte Carlo simulation. The present results indicated that NTL sheet is applicable to measurement of neutron spatial distribution. (author)

First direct measurement of the 2H(α,γ)6Li cross section at big bang energies and the primordial lithium problem.

Science.gov (United States)

Anders, M; Trezzi, D; Menegazzo, R; Aliotta, M; Bellini, A; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Davinson, T; Elekes, Z; Erhard, M; Formicola, A; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Marta, M; Mazzocchi, C; Prati, P; Rossi Alvarez, C; Scott, D A; Somorjai, E; Straniero, O; Szücs, T

2014-07-25

Recent observations of (6)Li in metal poor stars suggest a large production of this isotope during big bang nucleosynthesis (BBN). In standard BBN calculations, the (2)H(α,γ)(6)Li reaction dominates (6)Li production. This reaction has never been measured inside the BBN energy region because its cross section drops exponentially at low energy and because the electric dipole transition is strongly suppressed for the isoscalar particles (2)H and α at energies below the Coulomb barrier. Indirect measurements using the Coulomb dissociation of (6)Li only give upper limits owing to the dominance of nuclear breakup processes. Here, we report on the results of the first measurement of the (2)H(α,γ)(6)Li cross section at big bang energies. The experiment was performed deep underground at the LUNA 400 kV accelerator in Gran Sasso, Italy. The primordial (6)Li/(7)Li isotopic abundance ratio has been determined to be (1.5 ± 0.3) × 10(-5), from our experimental data and standard BBN theory. The much higher (6)Li/(7)Li values reported for halo stars will likely require a nonstandard physics explanation, as discussed in the literature.

Moessbauer spectra as a 'fingerprint' in tin-lithium compounds: Applications to Li-ion batteries

International Nuclear Information System (INIS)

Robert, F.; Lippens, P.E.; Olivier-Fourcade, J.; Jumas, J.-C.; Gillot, F.; Morcrette, M.; Tarascon, J.-M.

2007-01-01

Several Li-Sn crystalline phases, i.e. Li 2 Sn 5 , LiSn, Li 7 Sn 3 , Li 5 Sn 2 , Li 13 Sn 5 , Li 7 Sn 2 and Li 22 Sn 5 were prepared by ball-milling and characterized by X-ray powder diffraction and 119 Sn Moessbauer spectroscopy. The analysis of the Moessbauer hyperfine parameters, i.e. isomer shift (δ) and quadrupole splitting (Δ), made it possible to define two types of Li-Sn compounds: the Sn-richest compounds (Li 2 Sn 5 , LiSn) and the Li-richest compounds (Li 7 Sn 3 , Li 5 Sn 2 , Li 13 Sn 5 , Li 7 Sn 2 , Li 22 Sn 5 ). The isomer shift values ranged from 2.56 to 2.38 mm s -1 for Li 2 Sn 5 , LiSn and from 2.07 to 1.83 mm s -1 for Li 7 Sn 3 , Li 5 Sn 2 , Li 13 Sn 5 , Li 7 Sn 2 and Li 22 Sn 5 , respectively. A Δ-δ correlation diagram is introduced in order to identify the different phases observed during the electrochemical process of new Sn-based materials. This approach is illustrated by the identification of the phases obtained at the end of the first discharge of η-Cu 6 Sn 5 and SnB 0.6 P 0.4 O 2.9 . - Graphical abstract: Δ-δ correlation diagram for the different tin sites of the Li-Sn compounds. The symbols denote the different Li-Sn phases and the products obtained at the end of the discharge of η-Cu 6 Sn 5 and SnB 0.6 P 0.4 O 2.9 . The grey and the light-grey areas show Sn-centred polyhedra without and with one Sn first-nearest neighbours, respectively

Electrochemical Characteristics and Li+ Ion Intercalation Kinetics of Dual-phase Li4Ti5O12/Li2TiO3 Composite in Voltage Range of 0−3 V

KAUST Repository

Bhatti, Humaira S

2016-04-20

Li4Ti5O12, Li2TiO3 and dual-phase Li4Ti5O12/Li2TiO3 composite were prepared by sol-gel method with average particle size of 1 µm, 0.3 µm and 0.4 µm, respectively. Though Li2TiO3 is electrochemically inactive, the rate capability of Li4Ti5O12/Li2TiO3 is comparable to Li4Ti5O12 at different current rates. Li4Ti5O12/Li2TiO3 also shows good rate performance of 90 mA h g-1 at high rate of 10 C in voltage range of 1−3 V, attributable to increased interfaces in the composite. While Li4Ti5O12 delivers capacity retention of 88.6 % at 0.2 C over 50 cycles, Li4Ti5O12/Li2TiO3 exhibits no capacity fading at 0.2 C (40 cycles) and capacity retention of 98.45 % at 0.5 C (50 cycles). This highly stable cycling performance is attributed to the contribution of Li2TiO3 in preventing undesirable reaction of Li4Ti5O12 with the electrolyte during cycling. CV curves of Li4Ti5O12/Li2TiO3 in 0−3 V range exhibit two anodic peaks at 1.51 V and 0.7−0.0 V, indicating two modes of lithium intercalation into the lattice sites of active material. Owing to enhanced intercalation/de-intercalation kinetics in 0−3 V, composite electrode delivers superior rate performance of 203 mAh/g at 2.85 C and 140 mAh/g at 5.7 C with good reversible capacity retention over 100 cycles.

Electrochemical Characteristics and Li+ Ion Intercalation Kinetics of Dual-phase Li4Ti5O12/Li2TiO3 Composite in Voltage Range of 0−3 V

KAUST Repository

Bhatti, Humaira S; Anjum, Dalaver H.; Ullah, Shafiq; Ahmed, Bilal; Habib, Amir; Karim, Altaf; Hasanain, Syed Khurshid

2016-01-01

Li4Ti5O12, Li2TiO3 and dual-phase Li4Ti5O12/Li2TiO3 composite were prepared by sol-gel method with average particle size of 1 µm, 0.3 µm and 0.4 µm, respectively. Though Li2TiO3 is electrochemically inactive, the rate capability of Li4Ti5O12/Li2TiO3 is comparable to Li4Ti5O12 at different current rates. Li4Ti5O12/Li2TiO3 also shows good rate performance of 90 mA h g-1 at high rate of 10 C in voltage range of 1−3 V, attributable to increased interfaces in the composite. While Li4Ti5O12 delivers capacity retention of 88.6 % at 0.2 C over 50 cycles, Li4Ti5O12/Li2TiO3 exhibits no capacity fading at 0.2 C (40 cycles) and capacity retention of 98.45 % at 0.5 C (50 cycles). This highly stable cycling performance is attributed to the contribution of Li2TiO3 in preventing undesirable reaction of Li4Ti5O12 with the electrolyte during cycling. CV curves of Li4Ti5O12/Li2TiO3 in 0−3 V range exhibit two anodic peaks at 1.51 V and 0.7−0.0 V, indicating two modes of lithium intercalation into the lattice sites of active material. Owing to enhanced intercalation/de-intercalation kinetics in 0−3 V, composite electrode delivers superior rate performance of 203 mAh/g at 2.85 C and 140 mAh/g at 5.7 C with good reversible capacity retention over 100 cycles.

Li+ solvation and kinetics of Li+-BF4-/PF6- ion pairs in ethylene carbonate. A molecular dynamics study with classical rate theories

Science.gov (United States)

Chang, Tsun-Mei; Dang, Liem X.

2017-10-01

Using our polarizable force-field models and employing classical rate theories of chemical reactions, we examine the ethylene carbonate (EC) exchange process between the first and second solvation shells around Li+ and the dissociation kinetics of ion pairs Li+-[BF4] and Li+-[PF6] in this solvent. We calculate the exchange rates using transition state theory and correct them with transmission coefficients computed by the reactive flux, Impey, Madden, and McDonald approaches, and Grote-Hynes theory. We found that the residence times of EC around Li+ ions varied from 60 to 450 ps, depending on the correction method used. We found that the relaxation times changed significantly from Li+-[BF4] to Li+-[PF6] ion pairs in EC. Our results also show that, in addition to affecting the free energy of dissociation in EC, the anion type also significantly influences the dissociation kinetics of ion pairing.

Coincidence in the two-photon spectra of Li and Li2 at 735 nm

International Nuclear Information System (INIS)

DeGraffenreid, W; Sansonetti, Craig J

2005-01-01

A coincidence between the 2 2 S 1/2 -3 2 S 1/2 two-photon transition in the atomic spectrum of 6 Li and the X 1 Σ + g → E 1 Σ + g two-photon ro-vibrational series of 7 Li 2 was observed near 735 nm in a heat pipe oven using a tunable laser and thermionic diode detection scheme. The molecular transition obscures one component of the 6 Li atomic transition. Selective detection of the atomic transition was obtained by adding an intensity-modulated laser that drives atoms from the 3S to 16P state. The coincident molecular transition and four nearby molecular lines were identified using previously determined Dunham coefficients

Electrochemical behavior of LiV3O8 positive electrode in hybrid Li,Na-ion batteries

Science.gov (United States)

Maletti, S.; Sarapulova, A.; Tsirlin, A. A.; Oswald, S.; Fauth, F.; Giebeler, L.; Bramnik, N. N.; Ehrenberg, H.; Mikhailova, D.

2018-01-01

Vanadium(V)-containing oxides show superior intercalation properties for alkaline ions, although the performance of the material strongly depends on its surface morphology. In this work, intercalation activity of LiV3O8, prepared by a conventional solid state synthesis, is demonstrated for the first time in non-aqueous Li,Na-ion hybrid batteries with Na as negative electrode, and different Na/Li ratios in the electrolyte. In the pure Na-ion cell, one Na per formula unit of LiV3O8 can be reversibly inserted at room temperature via a two-step process, while further intercalation leads to gradual amorphisation of the material, with a specific capacity of 190 mAhg-1 after 10 cycles in the potential window of 0.8-3.4 V. Hybrid Li,Na-ion batteries feature simultaneous intercalation of Li+ and Na+ cations into LiV3O8, resulting in the formation of a second phase. Depending on the electrolyte composition, this second phase bears structural similarities either to Li0.7Na0.7V3O8 in Na-rich electrolytes, or to Li4V3O8 in Li-rich electrolytes. The chemical diffusion coefficients of Na+ and Li+ in crystalline LiV3O8 are very close, hence explaining the co-intercalation of these cations. As DFT calculations show, once formed, the Li0.7Na0.7V3O8-type structure favors intercalation of Na+, whereas the LiV3O8-type prefers to accommodate Li+ cations.

Deposition of Li{sub 4}Ti{sub 5}O{sub 12} and LiMn{sub 2}O{sub 4} films on the lithium-ion conductor of Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} sintered pellet

Energy Technology Data Exchange (ETDEWEB)

Wu, Xian Ming, E-mail: xianmingwu@163.com [College of Chemistry and Chemical Engineering, Jishou University, Jishou Hunan 416000 (China); Xiangxi Minerals and New Materials Research and Service Center, Jishou Hunan 416000 (China); Chen, Shang [College of Chemistry and Chemical Engineering, Jishou University, Jishou Hunan 416000 (China); Xiangxi Minerals and New Materials Research and Service Center, Jishou Hunan 416000 (China); He, Ze Qiang; Chen, Shou Bin; Li, Run Xiu [College of Chemistry and Chemical Engineering, Jishou University, Jishou Hunan 416000 (China)

2015-08-31

LiMn{sub 2}O{sub 4} and Li{sub 4}Ti{sub 5}O{sub 12} films were deposited on the lithium-ion conductor of Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} sintered pellet by spray technique. The effect of annealing temperature, annealing time, Li:Ti and Li:Mn molar ratio on the phase and crystallization of the films were investigated with X-ray diffraction. The LiMn{sub 2}O{sub 4}/Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3}/Li{sub 4}Ti{sub 5}O{sub 12} thin-film lithium-ion battery using Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} sintered pellet as both electrolyte and substrate was also studied. The results show that the effect of annealing temperature, annealing time, Li:Ti and Li:Mn molar ratio has great effect on the phase and crystallization of Li{sub 4}Ti{sub 5}O{sub 12} and LiMn{sub 2}O{sub 4} films deposited on the Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} sintered pellet. The optimal Li:Ti and Li:Mn molar ratio for the deposition of Li{sub 4}Ti{sub 5}O{sub 12} and LiMn{sub 2}O{sub 4} films on Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} sintered pellet are 7.2:5 and 1.05:2, respectively. The optimal annealing temperature and time for the deposition of LiMn{sub 2}O{sub 4} film on Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} sintered pellet are 650 °C and 10 min. While those for Li{sub 4}Ti{sub 5}O{sub 12} film are 700 °C and 10 min. The LiMn{sub 2}O{sub 4}/Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3}/Li{sub 4}Ti{sub 5}O{sub 12} thin-film battery offers a working voltage about 2.25 V and can be easily cycled. - Highlights: • LiMn{sub 2}O{sub 4} and Li{sub 4}Ti{sub 5}O{sub 12} films spray deposited on Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} sintered pellet • Film crystal phase depends on the spray solution composition and annealing conditions. • Prepared thin-film lithium-ion battery employs sintered pellet as electrolyte and substrate. • LiMn{sub 2}O{sub 4}/Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7

LiCaFeF6: A zero-strain cathode material for use in Li-ion batteries

Science.gov (United States)

de Biasi, Lea; Lieser, Georg; Dräger, Christoph; Indris, Sylvio; Rana, Jatinkumar; Schumacher, Gerhard; Mönig, Reiner; Ehrenberg, Helmut; Binder, Joachim R.; Geßwein, Holger

2017-09-01

A new zero-strain LiCaFeF6 cathode material for reversible insertion and extraction of lithium ions is presented. LiCaFeF6 is synthesized by a solid-state reaction and processed to a conductive electrode composite via high-energy ball-milling. In the first cycle, a discharge capacity of 112 mAh g-1 is achieved in the voltage range from 2.0 V to 4.5 V. The electrochemically active redox couple is Fe3+/Fe2+ as confirmed by Mössbauer spectroscopy and X-ray absorption spectroscopy. The compound has a trigonal colquiriite-type crystal structure (space group P 3 bar 1 c). By means of in situ and ex situ XRD as well as X-ray absorption fine structure spectroscopy a reversible response to Li uptake/release is found. For an uptake of 0.8 mol Li per formula unit only minimal changes occur in the lattice parameters causing a total change in unit cell volume of less than 0.5%. The spatial distribution of cations in the crystal structure as well as the linkage between their corresponding fluorine octahedra is responsible for this very small structural response. With its zero-strain behaviour this material is expected to exhibit only negligible mechanical degradation. It may be used as a cathode material in future lithium-ion batteries with strongly improved safety and cycle life.

Li diffusion and the effect of local structure on Li mobility in Li2O-SiO2 glasses.

Science.gov (United States)

Bauer, Ute; Welsch, Anna-Maria; Behrens, Harald; Rahn, Johanna; Schmidt, Harald; Horn, Ingo

2013-12-05

Aimed to improve the understanding of lithium migration mechanisms in ion conductors, this study focuses on Li dynamics in binary Li silicate glasses. Isotope exchange experiments and conductivity measurements were carried out to determine self-diffusion coefficients and activation energies for Li migration in Li2Si3O7 and Li2Si6O13 glasses. Samples of identical composition but different isotope content were combined for diffusion experiments in couples or triples. Diffusion profiles developed between 511 and 664 K were analyzed by femtosecond laser ablation combined with multiple collector inductively coupled plasma mass spectrometry (fs LA-MC-ICP-MS) and secondary ion mass spectrometry (SIMS). Analyses of diffusion profiles and comparison of diffusion data reveal that the isotope effect of lithium diffusion in silicate glasses is rather small, consistent with classical diffusion behavior. Ionic conductivity of glasses was measured between 312 and 675 K. The experimentally obtained self-diffusion coefficient, D(IE), and ionic diffusion coefficient, D(σ), derived from specific DC conductivity provided information about correlation effects during Li diffusion. The D(IE)/D(σ) is higher for the trisilicate (0.27 ± 0.05) than that for the hexasilicate (0.17 ± 0.02), implying that increasing silica content reduces the efficiency of Li jumps in terms of long-range movement. This trend can be rationalized by structural concepts based on nuclear magnetic resonance (NMR) and Raman spectroscopy as well as molecular dynamic simulations, that is, lithium is percolating in low-dimensional, alkali-rich regions separated by a silica-rich matrix.

Nuclear charge radius of 11Li

International Nuclear Information System (INIS)

Sanchez, Rodolfo; Noertershaeuser, Wilfried; Dax, Andreas; Ewald, Guido; Goette, Stefan; Kirchner, Reinhard; Kluge, H.-Juergen; Kuehl, Thomas; Wojtaszek, Agnieszka; Bushaw, Bruce A.; Drake, Gordon W. F.; Yan Zongchao; Zimmermann, Claus; Albers, Daniel; Behr, John; Bricault, Pierre; Dilling, Jens; Dombsky, Marik; Lassen, Jens; Phil Levy, C. D.

2006-01-01

We have determined the nuclear charge radius of 11 Li by high-precision laser spectroscopy. The experiment was performed at the TRIUMF-ISAC facility where the 7 Li- 11 Li isotope shift (IS) was measured in the 2s → 3s electronic transition using Doppler-free two-photon spectroscopy with a relative accuracy better than 10 -5 . The accuracy for the IS of the other lithium isotopes was also improved. IS's are mainly caused by differences in nuclear mass, but changes in proton distribution also give small contributions. Comparing experimentally measured IS with advanced atomic calculation of purely mass-based shifts, including QED and relativistic effects, allows derivation of the nuclear charge radii. The radii are found to decrease monotonically from 6 Li to 9 Li, and then increase with 11 Li about 11% larger than 9 Li. These results are a benchmark for the open question as to whether nuclear core excitation by halo neutrons is necessary to explain the large nuclear matter radius of 11 Li; thus, the results are compared with a number of nuclear structure models.

Contribution to the study of excited levels of 7Be obtained from the reaction 6Li (p, α)

International Nuclear Information System (INIS)

Beaumevieille, H.

1964-05-01

The interpretation of the results of the reaction 6 Li (p, α) in the energy range 100 keV to 3 MeV has been done with the next levels of 7 Be : 3/2- (5,9 MeV), 3/2+ (6,2 MeV), 5/2- (7,18 MeV) and a level the characteristics of which may be 1/2+ or 4 P (9,5 MeV). (author) [fr

The effect of isotopic mass on the velocity of sound in liquid Li

International Nuclear Information System (INIS)

McAlister, S.P.; Crozier, E.D.; Cochran, J.F.

1976-01-01

Results are presented for the velocity of ultrasound in liquid 6 Li- 7 Li alloys of composition 4.5, 49.7 and 99.9 at % Li for temperatures up to 700 0 C. At the melting point the ratio of the velocity of sound in 6 Li to that in 7 Li was found within experimental error to equal (M 7 /M 6 )sup(1/2), the result expected for classical liquids which differ only in the isotopic mass M. In the alloy of 49.7 at % 7 Li the sound velocity exceeded by 0.6% the value expected for a thermodynamically ideal alloy. This result is discussed in terms of the theoretical treatment by Parrinello et al, (J. Phys. C.: Solid St. Phys.; 7:2577 (1974)) of collective excitations in binary isotopic fluids. (author)

Evaluation of neutron nuclear data for 7Li

International Nuclear Information System (INIS)

Yu Baosheng; Cai Dunjiu

1993-01-01

New complete neutron data for 7 Li have been evaluated for CENDL-2. It updates our work in 1978 for CENDL-1 to extend incident neutron energy range from 10 -5 eV to 20 MeV. Combining new experimental data and benchmark testing, the tritium production cross section were improved. The comparison of present evaluation with ENDF/B-6 and JENDL-3 has been made

A Li-Garnet composite ceramic electrolyte and its solid-state Li-S battery

Science.gov (United States)

Huang, Xiao; Liu, Cai; Lu, Yang; Xiu, Tongping; Jin, Jun; Badding, Michael E.; Wen, Zhaoyin

2018-04-01

A high strength Li-Garnet solid electrolyte composite ceramic is successfully prepared via conventional solid state method with Li6.4La3Zr1.4Ta0.6O12 and nano MgO powders. Well sintered ceramic pellets and bars are obtained with 0-9 wt.% MgO. Fracture strength is approximately 135 MPa for composite ceramics with 5-9 wt.% MgO, which is ∼50% higher than that of pure Li6.4La3Zr1.4Ta0.6O12 (90 MPa). Lithium-ion conductivity of the composite is above 5 × 10-4 S cm-1 at room temperature; comparable to the pure Li6.4La3Zr1.4Ta0.6O12 material. SEM cross-sections of the composite ceramic shows a much more uniform microstructure comparing with pure ones, owing to the grain growth inhibition effect of the MgO second phase. A battery cell consisting of Li/composite ceramics/Sulfur-Carbon at 25 °C exhibits a capacity of 685 mAh g-1 at 0.2 C at the 200th cycle, while maintaining a coulombic efficiency of 100%. These results indicate that the composite ceramic Li6.4La3Zr1.4Ta0.6O12-MgO is promising for the production of electrolyte membrane and fabrication of Li-Sulfur batteries.

Electromagnetic form factors and vertex constants for 6Li

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Shvarts, I.A.

1977-01-01

It has been assumed that the main contribution to the rapidly changing part of the charge form factor of 6 Li provides the amplitude of the triangle diagram containing virtual lines of deuteron and α particle. The vertex constant G 2 for the 6 Li→α+d decay is expressed through the nuclear charge radii for 6 Li, d, and α. Taking into account coulomb interaction in the vertex of the 6 Li→α+d reaction increases G 2 by about a factor of two. The account of virtuality of a deuteron cluster also leads to an increase in G 2

Computer modelling of defect structure and rare earth doping in LiCaAlF sub 6 and LiSrAlF sub 6

CERN Document Server

Amaral, J B; Valerio, M E G; Jackson, R A

2003-01-01

This paper describes a computational study of the mixed metal fluorides LiCaAlF sub 6 and LiSrAlF sub 6 , which have potential technological applications when doped with a range of elements, especially those from the rare earth series. Potentials are derived to represent the structure and properties of the undoped materials, then defect properties are calculated, and finally solution energies for rare earth elements are calculated, enabling preferred dopant sites and charge compensation mechanisms to be predicted.

Dosimetric properties of Li2 B4 O7: Tm pellets

International Nuclear Information System (INIS)

Rzyski, B.M.; Morato, S.P.

1987-10-01

Pellets produced out of thulium doped lithium tetraborate, (Li 2 B 4 O 7 :Tm), for thermoluminescent, (TL), dosimetry present low sensibility to environment conditions. Humidity, ambiet temperature, fading and handling during TL reading have almost no influence on the TL properties of the pellets prepared according the receipt given in this paper. The structure of the TL glow curve for the irradiated Li 2 B 4 O 7 : Tm pellet is rather simple and the TL response is linear in the range of 3x10 -4 to 7x10 2 Gy. The dosimetric properties of Li 2 B 4 O 7 : Tm in pellet form makes it a competitor with other TL phosphors. (author) [pt

Elastic Scattering Of 6,7Li+80Se At Near And Above Barrier Energies

International Nuclear Information System (INIS)

Fimiani, L.; Marti, G. V.; Capurro, O. A.; Barbara, E. de; Testoni, J. E.; Zalazar, L.; Arazi, A.; Cardona, M. A.; Carnelli, P.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Fernandez Niello, J. O.

2010-01-01

In this work we propose to study the elastic scattering of the weakly bound projectiles 6,7 Li on an intermediate mass target 80 Se. From the experimental results presented here, precise angular distributions at energies below, around and above the nominal Coulomb barriers of the systems were obtained. The final goal of our work is to determine the characteristic parameters of the optical potential and use them to address the question of whether the usual threshold anomaly or the breakup threshold anomaly are present or not in these systems.

Fusion cross sections measurement for 6Li + 159Tb

International Nuclear Information System (INIS)

Pradhan, M.K.; Mukherjee, A.; Kshetri, R.; Roy, Subinit; Basu, P.; Goswami, A.; Saha Sarkar, M.; Ray, M.; Parkar, V.; Santra, S.; Kailas, S.; Palit, R.

2009-01-01

In order to investigate the effect of projectile breakup threshold energy on fusion in mass region around A∼170, we have carried out a systematic investigation of the fusion (both CF and ICF) cross sections for the systems 11 B, 10 B + 159 Tb and 7 Li + 159 Tb at energies near and close to the barrier where 11 B was considered to be a strongly bound nucleus. The nucleus 10 B has a α-separation energy of 4.5 MeV. The measurements show that the extent of suppression of CF cross sections is correlated with the α-separation energies of the projectiles. As a further continuation of this work, we have recently carried out fusion excitation function measurement for the system 6 Li + 159 Tb (Coulomb barrier 27 MeV) at energies near and close to the barrier

Ce and Eu-doped LiSrAlF6 scintillators for neutron detectors

International Nuclear Information System (INIS)

Yanagida, Takayuki; Kawaguchi, Noriaki; Fujimoto, Yutaka; Yokota, Yuui; Yamazaki, Atsushi; Watanabe, Kenichi; Kamada, Kei; Yoshikawa, Akira; Chani, Valery

2011-01-01

Ce 1%, Eu 1%, and Eu 2%-doped LiSrAlF 6 (LiSAF) single crystals were grown by the micro-pulling-down method for thermal neutron applications. The crystals were transparent, 2.0 mm in diameter and 20–40 mm in length. Neither visible inclusions nor cracks were observed. Their transmittance spectra were measured. The strong absorption lines were observed at 200, 240, and 300 nm for Ce:LiSAF due to Ce 3+ 4f–5d transition. In Eu:LiSAF, 200 (4f–5d) and 300 (4f–4f) nm absorption lines were detected. The samples demonstrated strong emission peaks at 300 nm (Ce:LiSAF) and 370 nm (Eu:LiSAFs) when they were irradiated with 241 Am α-rays simulating the α-particles from the 6 Li(n, α) reaction. Thermal neutron responses were examined under 252 Cf irradiation. The absolute light yield of Ce, Eu 1%, and Eu 2% crystals were 3400, 18000, and 30000 ph/n, respectively. Main components of the scintillation decay time of Ce, Eu 1%, and Eu 2%-doped LiSAFs were 63, 1293, and 1205 ns.

Electronic Properties of LiFePO4 and Li doped LiFePO4

International Nuclear Information System (INIS)

Zhuang, G.V.; Allen, J.L.; Ross, P.N.; Guo, J.-H.; Jow, T.R.

2005-01-01

The potential use of different iron phosphates as cathode materials in lithium-ion batteries has recently been investigated.1 One of the promising candidates is LiFePO4. This compound has several advantages in comparison to the state-of-the-art cathode material in commercial rechargeable lithium batteries. Firstly, it has a high theoretical capacity (170 mAh/g). Secondly, it occurs as mineral triphylite in nature and is inexpensive, thermally stable, non-toxic and non-hygroscopic. However, its low electronic conductivity (∼10-9 S/cm) results in low power capability. There has been intense worldwide research activity to find methods to increase the electronic conductivity of LiFePO4, including supervalent ion doping,2 introducing non-carbonaceous network conduction3 and carbon coating, and the optimization of the carbon coating on LiFePO4 particle surfaces.4 Recently, the Li doped LiFePO4 (Li1+xFe1-xPO4) synthesized at ARL has yield electronic conductivity increase up to 106.5 We studied electronic structure of LiFePO4 and Li doped LiFePO4 by synchrotron based soft X-ray emission (XES) and X-ray absorption (XAS) spectroscopies. XAS probes the unoccupied partial density of states, while XES the occupied partial density of states. By combining XAS and XES measurements, we obtained information on band gap and orbital character of both LiFePO4 and Li doped LiFePO4. The occupied and unoccupied oxygen partial density of states (DOS) of LiFePO4 and 5 percent Li doped LiFePO4 are presented in Fig. 1. Our experimental results clearly indicate that LiFePO4 has wideband gap (∼ 4 eV). This value is much larger than what is predicted by DFT calculation. For 5 percent Li doped LiFePO4, a new doping state was created closer to the Fermi level, imparting p-type conductivity, consistent with thermopower measurement. Such observation substantiates the suggestion that high electronic conductivity in Li1.05Fe0.95 PO4 is due to available number of charge carriers in the material

Dosimeter properties of Ce and Eu doped LiCaAlF6

International Nuclear Information System (INIS)

Yanagida, Takayuki; Fujimoto, Yutaka; Watanabe, Kenichi; Fukuda, Kentaro

2014-01-01

Optical, scintillation properties, optical stimulated luminescence, and thermally stimulated luminescence of Ce 1, 3, and 5% doped and Eu 1, 1.5, and 2% doped LiCaAlF 6 crystals fabricated by Tokuyama Corp. were investigated. In transmittance, absorption was proportional to dopant concentrations and typical optical quantum yield of Ce and Eu-doped LiCaAlF 6 were 40 and 100%, respectively. Scintillation wavelength and decay time profiles were investigated under X-ray irradiation. Ce 3+ and Eu 2+ 5d-4f luminescence appeared around 300 nm and 370 nm with typical decay time of 40 ns and 1.5 μs, respectively. Optically stimulated luminescence of Ce-doped ones appeared under 405 nm stimulation with detectable intensity while those of Eu doped ones were quite weak. Thermally stimulated luminescence of Ce- and Eu-doped LiCaAlF 6 were enough strong and they exhibited good response function from 1 to 1000 mGy exposure. - Highlights: • Optical, scintillation, OSL, and TSL properties of Ce or Eu differently doped LiCaAlF6 were studied. • PL quantum yield of Ce and Eu doped LiCaAlF6 showed 40% and 100%, respectively. • OSL was observed in Ce-doped LiCaAlF6. • TSL was observed in both material systems and exhibited a good dose response from 1 to 1000 mGy

Corrosion of type 316 stainless steel in molten LiF-LiCl-LiBr

International Nuclear Information System (INIS)

Tortorelli, P.F.; DeVan, J.H.; Keiser, J.R.

1981-01-01

The properties of LiF-LiCl-LiBr salt make it attractive as a solvent for extracting tritium from a fusion reactor lithium blanket. Consequently, the corrosion of type 316 stainless steel by flowing (about 15 mm/s) LiF-LiCl-LiBr at a maximum temperature of 535 0 C was studied to determine whether compatibility with the structural material would be limiting in such a system. The corrosion rate was found to be low ( 0 C (approximately that of type 316 stainless steel exposed to lithium flowing at a similar velocity). At the proposed operating temperature (less than or equal to approx. 535 0 C), however, it appears that type 316 stainless steel has acceptable compatibility with the tritium-processing salt LiF-LiCl-LiBr for use with a lithium blanket

The Li-7((d)over-right-arrow, n(0))Be-8 and Li-7((d)over-right-arrow, n(1))Be-8 reactions below 160 keV

NARCIS (Netherlands)

Sabourov, A.; Ahmed, M. W.; Blackston, M. A.; Crowell, A. S.; Howell, C. R.; Joshi, K.; Nelson, S. O.; Perdue, B. A.; Sabourov, K.; Tonchev, A.; Weller, H. R.; Prior, R. M.; Spraker, M. C.; Braizinha, B.; Kalantar-Nayestanaki, N.

2006-01-01

The polarization observables have been determined for the Li-7(d,n(0))Be-8 and Li-7(d,n(1))Be-8 reactions at beam energies between 80 and 160 keV. A Transition Matrix Element (TME) analysis revealed unique, dominant p-wave solutions for both neutron channels. The polarization observables were

Astrophysical S factor for the 7Li(d,n0)8Be and 7Li(d,n1)8Be reactions

International Nuclear Information System (INIS)

Sabourov, A.; Ahmed, M.W.; Blackston, M.A.; Crowell, A.S.; Howell, C.R.; Perdue, B.A.; Sabourov, K.; Tonchev, A.; Weller, H.R.; Prior, R.M.; Spraker, M.C.

2006-01-01

The absolute astrophysical S factor and cross section for the 7 Li(d,n 0 ) 8 Be and 7 Li(d,n 1 ) 8 Be reactions have been determined using deuteron beams with energies between 45 and 80 keV. The slope of the S factor is consistent with zero in the n 0 case but is slightly negative in the n 1 case. The S factor for the sum of both neutron groups at c.m. energies below 70 keV is S(E)=5400(±1500)-37(±21)E keV b, where E is the c.m. energy in keV

Importance of the tensor interaction in the (/sup 7/Li, /sup 7/Be) reaction

Energy Technology Data Exchange (ETDEWEB)

Dodd, A.C.; Clarke, N.M.; Coopersmith, J.; Griffiths, R.J.; Pearce, K.I.; Stanley, B.; Cook, J.

1985-09-01

Data for the /sup 28/Si(/sup 7/Li, /sup 7/Be)/sup 28/Al reaction at 72 MeV and for the /sup 26/Mg(/sup 7/Li, /sup 7/Be)/sup 26/Na reaction at 88 MeV are presented together with one-step DWBA calculations using microscopic form factors. The tensor interaction is shown to be important to explain the structureless nature of the angular distributions.

Scintillation properties of LiF–SrF{sub 2} and LiF–CaF{sub 2} eutectic

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Takayuki, E-mail: yanagida@lsse.kyutech.ac.jp [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196 (Japan); Kawaguchi, Noriaki [Tokuyama Corporation, 1-1 Mikage-cho, Shunan-shi, Yamaguchi 745-8648 (Japan); Fujimoto, Yutaka [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196 (Japan); Fukuda, Kentaro [Tokuyama Corporation, 1-1 Mikage-cho, Shunan-shi, Yamaguchi 745-8648 (Japan); Watanabe, Kenichi; Yamazaki, Atsushi; Uritani, Akira [Quantum Science and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2013-12-15

Dopant free eutectic scintillators {sup 6}LiF–SrF{sub 2} and {sup 6}LiF–CaF{sub 2} were developed by the vertical Bridgeman method for the purpose of thermal neutron detection. The molar ratio of LiF and Ca/SrF{sub 2} was 4:1 on its eutectic composition. The α-ray induced radioluminescence spectra of the scintillators showed intense emission peak at 300 nm due to the emission from the self-trapped exciton in Ca/SrF{sub 2} layers. When the samples were irradiated with {sup 252}Cf neutrons, {sup 6}LiF–SrF{sub 2} and {sup 6}LiF–CaF{sub 2} exhibited the light yields of 4700 and 9400 ph/n, respectively. Scintillation decay times of {sup 6}LiF–SrF{sub 2} and {sup 6}LiF–CaF{sub 2} were accepted for scintillation detectors, 90 and 250 ns, respectively. -- Highlights: • Nondoped LiF–CaF{sub 2} and LiF–SrF{sub 2} eutectic scinitillators are reported for the first time. • Two sample showed self-trapped exciton emission. • LiF–SrF{sub 2} sample exhibited the light yield of 9400 ph/n and this value was comparable to conventional materials doped with rare earth ions. • Scintillation decay times of LiF–CaF{sub 2} and LiF–SrF{sub 2} were 250 and 90 ns, respectively.

Synthesis and structure of novel lithium-ion conductor Li{sub 7}Ge{sub 3}PS{sub 12}

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yuki [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Suzuki, Kota [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Matsui, Naoki [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Hirayama, Masaaki [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Kanno, Ryoji, E-mail: kanno@echem.titech.ac.jp [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan)

2017-02-15

The novel lithium-ion conductor Li{sub 7}Ge{sub 3}PS{sub 12} was synthesized by slow cooling from the ternary Li{sub 2}S–GeS{sub 2}–P{sub 2}S{sub 5} system, and was shown to exhibit a cubic argyrodite-type structure. The phase composition was determined by varying the ratio of starting materials; the observed monophasic properties were close to those for the Li{sub 7}Ge{sub 3}PS{sub 12} composition. The lattice parameter (a =9.80192(3) Å) of Li{sub 7}Ge{sub 3}PS{sub 12} was slightly smaller than that of Li{sub 7}PS{sub 6} (a =9.993 Å), indicating that substitution of a Li cation by the smaller Ge cation contracted the cubic lattice. In addition, the novel structure consisted of a framework composed of four isolated (Ge/P)S{sub 4} tetrahedra. Li{sup +} ions occupied tetrahedral sites within the framework, forming a three-dimensional conduction pathway. Finally, Li{sub 7}Ge{sub 3}PS{sub 12} exhibited a high ionic conductivity of 1.1×10{sup −4} S cm{sup −1} at 25 °C and an activation energy of 25 kJ mol{sup −1}. - Graphical abstract: A novel Li{sub 7}Ge{sub 3}PS{sub 12} solid lithium ion conductor, with cubic argyrodite strucuture, shows high ion conductivity of 1.1×10{sup –4} S cm{sup –1} with an activation energy of 25 kJ mol{sup –1}. The argyrodite structure consists of (Ge/P)S{sub 4} tetrahedra units along with partial occupation of lithium and germanium at 48 h site. - Highlights: • A novel lithium-ion conductor Li{sub 7}Ge{sub 3}PS{sub 12} was detected. • This was achieved through slow cooling of the ternary Li{sub 2}S–GeS{sub 2}–P{sub 2}S{sub 5} system. • This novel conductor revealed a cubic argyrodite-type structure. • Li{sub 7}Ge{sub 3}PS{sub 12} exhibited a high ionic conductivity of 1.1×10{sup −4} S cm{sup −1} at 25 °C. • These properties will aid in the design of superior lithium-ion conductors.

Exoelectron emission from surface layer of Li2B4O7 glass ceramics

International Nuclear Information System (INIS)

Kawamoto, Takamichi; Katsube, Shizuko; Yanagisawa, Hideo; Kikuchi, Riichi; Kawanishi, Masaharu.

1984-01-01

The thermally stimulated exoelectron emission (TESS) of Li 2 B 4 O 7 glass ceramics was investigated for its application to the dosimetric use. It has been found the TSEE glow patterns of Li 2 B 4 O 7 glass ceramics and of the thin layer of LiF evaporated on Li 2 B 4 O 7 glass ceramics depend on the kind of radiations irradiated. The TSEE glow pattern of the duplicated structure sample indicated a possibility of determining the dose of each kind of radiation separately in the mixed radiation field. (author)

Hydrogen retention in Li and Li-C-O films

Science.gov (United States)

Buzi, Luxherta; Nelson, Andrew O.; Yang, Yuxin; Kaita, Robert; Koel, Bruce E.

2017-10-01

The efficiency of Li in binding H isotopes has led to reduced recycling in magnetic fusion devices and improved plasma performance. Since elemental Li surfaces are challenging to maintain in fusion devices due to the presence of impurities, parameterizing and understanding the mechanisms for H retention in various Li compounds (Li-C-O), in addition to pure Li, is crucial for Li plasma-facing material applications. To determine H retention in Li and Li-C-O films, measurements were done under ultrahigh vacuum conditions using temperature programmed desorption (TPD). Thin Li films (20 monolayers) were deposited on a nickel single crystal substrate and irradiated with 500 eV H2+ions at surface temperatures from 90K to 520K. Initial measurements on Li and Li-O films showed that the retention was comparable and dropped exponentially with surface temperature, from 95% at 90 K to 35% at 520 K. Auger electron spectroscopy and TPD showed that H was retained as lithium hydride (LiH) in pure Li and as lithium hydroxide (LiOH) in Li2O, which decomposed to H2O and Li2O at temperatures higher than 470K. H retention in Li-C and Li-C-O films will be determined over a similar temperature range, and the sputtering rate of these layers with H ions will also be reported. This material is based upon work supported by the U.S. Department of Energy, Office of Science/Fusion Energy Sciences under Award Number DE-SC0012890.

Density Functional Theory Study of the Interaction of Hydrogen with Li6C60.

Science.gov (United States)

Wang, Qian; Jena, Puru

2012-05-03

Hydrogen storage properties of Li-coated C60 fullerene have been studied using density functional theory within the local density as well as generalized gradient approximation. Hydrogen atoms are found to bind to Li6C60 in two distinct forms, with the first set attaching to C atoms, not linked to Li, in atomic form. Once all such C atoms are saturated with hydrogen, the second set of hydrogen atoms bind quasi-molecularly to the Li atoms, five of which remain in the exohedral and the sixth in the endohedral position. The corresponding hydrogen gravimetric density in Li6C60H40 is 5 wt %. Desorption of hydrogen takes place in succession, the ones bound quasi-molecularly desorbing at a temperature lower than the ones bound atomically. The results are compared with the recent experiment on hydrogen adsorption in Li6C60.

Fusion cross sections for 6,7Li + 24Mg reactions at energies below and above the barrier

International Nuclear Information System (INIS)

Ray, M.; Mukherjee, A.; Pradhan, M. K.; Kshetri, Ritesh; Sarkar, M. Saha; Dasmahapatra, B.; Palit, R.; Majumdar, I.; Joshi, P. K.; Jain, H. C.

2008-01-01

Measurement of fusion cross sections for the 6,7 Li + 24 Mg reactions by the characteristic γ-ray method has been done at energies from below to well above the respective Coulomb barriers. The fusion cross sections obtained from these γ-ray cross sections for the two systems are found to agree well with the total reaction cross sections at low energies. The relatively large difference between total cross sections and measured fusion cross sections at higher energies is consistent with the fact that other channels, in particular breakup, open up with an increase of bombarding energy. The breakup channel, however, appears not to have any influence on fusion cross sections. The critical angular momenta (l cr ) deduced from the fusion cross sections are found to have an energy dependence similar to other Li-induced reactions

{sup 6}LiF oleic acid capped nanoparticles entrapment in siloxanes for thermal neutron detection

Energy Technology Data Exchange (ETDEWEB)

Carturan, S., E-mail: sara.carturan@lnl.infn.it; Maggioni, G., E-mail: Gianluigi.maggioni@lnl.infn.it [Department of Physics and Astronomy, University of Padova, Via Marzolo 8, 35100 Padova (Italy); INFN, Laboratori Nazionali di Legnaro, Viale dell’Università 2, 35020 Legnaro (Italy); Marchi, T.; Gramegna, F.; Cinausero, M. [INFN, Laboratori Nazionali di Legnaro, Viale dell’Università 2, 35020 Legnaro (Italy); Quaranta, A. [Department of Industrial Engineering, University of Trento, Trento (Italy); INFN, Tifpa, Trento (Italy); Palma, M. Dalla [INFN, Laboratori Nazionali di Legnaro, Viale dell’Università 2, 35020 Legnaro (Italy); Department of Industrial Engineering, University of Trento, Trento (Italy)

2016-07-07

The good light output of siloxane based scintillators as displayed under γ-rays and α particles has been exploited here to obtain clear and reliable response toward thermal neutrons. Sensitization towards thermal neutrons has been pursued by adding {sup 6}LiF, in form of nanoparticles. Aiming at the enhancement of compatibility between the inorganic nanoparticles and the low polarity, siloxane based surrounding medium, oleic acid-capped {sup 6}LiF nanoparticles have been synthesized by thermal decomposition of Li trifluoroacetate. Thin pellets siloxane scintillator maintained their optical transmittance up to weight load of 2% of {sup 6}Li. Thin samples with increasing {sup 6}Li concentration and thicker ones with fixed {sup 6}Li amount have been prepared and tested with several sources (α, γ-rays, moderated neutrons). Light output as high as 80% of EJ212 under α irradiation was measured with thin samples, and negligible changes have been observed as a result of {sup 6}LiF addition. In case of thick samples, severe light loss has been observed, as induced by opacity. Nevertheless, thermal neutrons detection has been assessed and the data have been compared with GS20, based on Li glass, taken as a reference material.

Astrophysical Li-7 as a product of big bang nucleosynthesis and galactic cosmic-ray spallation

Science.gov (United States)

Olive, Keith A.; Schramm, David N.

1992-01-01

The astrophysical Li-7 abundance is considered to be largely primordial, while the Be and B abundances are thought to be due to galactic cosmic ray (GCR) spallation reactions on top of a much smaller big bang component. But GCR spallation should also produce Li-7. As a consistency check on the combination of big bang nucleosynthesis and GCR spallation, the Be and B data from a sample of hot population II stars is used to subtract from the measured Li-7 abundance an estimate of the amount generated by GCR spallation for each star in the sample, and then to add to this baseline an estimate of the metallicity-dependent augmentation of Li-7 due to spallation. The singly reduced primordial Li-7 abundance is still consistent with big bang nucleosynthesis, and a single GCR spallation model can fit the Be, B, and corrected Li-7 abundances for all the stars in the sample.

Evidence for a vanishing ⁶Li/⁷Li isotopic signature in the metal-poor halo star HD84937

DEFF Research Database (Denmark)

Lind, K.; Asplund, M.; Collet, Remo

2012-01-01

The claimed detections of 6Li in the atmospheres of some metal-poor halo stars have lead to speculative additions to the standard model of Big Bang nucleosynthesis and the early Universe, as the inferred abundances cannot be explained by Galactic cosmic ray production. A prominent example of a so...

Device fabrication, characterization, and thermal neutron detection response of LiZnP and LiZnAs semiconductor devices

Science.gov (United States)

Montag, Benjamin W.; Ugorowski, Philip B.; Nelson, Kyle A.; Edwards, Nathaniel S.; McGregor, Douglas S.

2016-11-01

Nowotny-Juza compounds continue to be explored as candidates for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present day gas-filled 3He and 10BF3 detectors. The 6Li(n,t)4He reaction yields a total Q-value of 4.78 MeV, larger than 10B, an energy easily identified above background radiations. Hence, devices fabricated from semiconductor compounds having either natural Li (nominally 7.5% 6Li) or enriched 6Li (usually 95% 6Li) as constituent atoms may provide a material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and As sealed under vacuum (10-6 Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace [1]. The raw synthesized material indicated the presence high impurity levels (material and electrical property characterizations). A static vacuum sublimation in quartz was performed to help purify the synthesized material [2,3]. Bulk crystalline samples were grown from the purified material [4,5]. Samples were cut using a diamond wire saw, and processed into devices. Bulk resistivity was determined from I-V curve measurements, ranging from 106-1011 Ω cm. Devices were characterized for sensitivity to 5.48 MeV alpha particles, 337 nm laser light, and neutron sensitivity in a thermal neutron diffracted beam at the Kansas State University TRIGA Mark II nuclear reactor. Thermal neutron reaction product charge induction was measured with a LiZnP device, and the reaction product spectral response was observed.

The dehydrogenation performance and reaction mechanisms of Li{sub 3}AlH{sub 6} with TiF{sub 3} additive

Energy Technology Data Exchange (ETDEWEB)

Liu, Shu-Sheng [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yao; Sun, Li-Xian; Zhang, Jian; Zhao, Jun-Ning [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Xu, Fen [Faculty of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Huang, Feng-Lei [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

2010-05-15

For Li{sub 3}AlH{sub 6} prepared by mechanical milling method, the dissociation reaction enthalpy and activation energy are calculated to be 22.1 kJ mol{sup -1} H{sub 2} and 133.7 {+-} 2.7 kJ mol{sup -1}, respectively. The dehydrogenation performance of Li{sub 3}AlH{sub 6} is greatly enhanced by TiF{sub 3} additive, especially in the kinetic behaviors. For the Li{sub 3}AlH{sub 6} + 10 mol% TiF{sub 3} sample, the starting temperature of dehydrogenation is obviously decreased by 60 C from that of pure Li{sub 3}AlH{sub 6} (190 C), and 3.0 wt.% H{sub 2} may be released within 1000 s at 120 C under an initial vacuum. With the amount of TiF{sub 3} increasing, the starting temperature decreases and the kinetics improves due to the decrease in the activation energy. The X-ray diffraction (XRD) together with thermogravimetric analysis (TGA) results show that there are three mechanochemical reactions involved during milling: i) Li{sub 3}AlH{sub 6} + TiF{sub 3} {yields} 3 LiF + Al + Ti + 3H{sub 2}, ii) Ti + H{sub 2} {yields} TiH{sub 2}, iii) 3 Al + Ti {yields} Al{sub 3}Ti. The in-situ formed Ti species (TiH{sub 2} and Al{sub 3}Ti) co-catalyze the thermal dehydrogenation of Li{sub 3}AlH{sub 6}. (author)

Cross-section of the reaction {sup 7}Li(p,n){sup 7}Be close to the threshold

Energy Technology Data Exchange (ETDEWEB)

Shorin, V S [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

1997-06-01

The status of data on the cross-section of the reaction {sup 7}Li(p,n){sup 7}Be close to the threshold is reviewed. On the basis of recent data on the cross-section of the inverse reaction {sup 7}Be(n,p){sup 7}Li and certain theoretical models, an evaluation is performed of the total cross-section of the {sup 7}Li(p,n)-reaction in the proton energy region up to 2 MeV. (author). 16 refs, 1 fig., 1 tab.

Searching for “LiCrIIPO4”

International Nuclear Information System (INIS)

Mosymow, E.; Glaum, R.; Kremer, R.K.

2014-01-01

The two new phosphates LiCr II 4 (PO 4 ) 3 and Li 5 Cr II 2 Cr III (PO 4 ) 4 are discovered as equilibrium phases (ϑ=800 °C) in the quarternary system Li/Cr/P/O. Their crystal structures have been determined from single-crystal X-ray diffraction data (LiCr II 4 (PO 4 ) 3 : violet-blue, Pnma (no. 62), Z=4, a=6.175(1) Å, b=14.316(3) Å, c=10.277(2) Å, 100 parameters, R 1 =0.028, wR 2 =0.08, 2060 unique reflections with F o >4σ(F o ); Li 5 Cr II 2 Cr III (PO 4 ) 4 : greyish-green, P1 ¯ (no. 2), Z=1, a=4.9379(7) Å, b=7.917(2) Å, c=8.426(2) Å, α=109.98(2)°, β=90.71(1)°, γ=104.91(1)°, 131 parameters, R 1 =0.022, wR 2 =0.067, 1594 unique reflections with F o >4σ(F o )). Li 5 Cr II 2 Cr III (PO 4 ) 4 adopts an hitherto unknown structure type. The crystal structure of LiCr II 4 (PO 4 ) 3 is isotypic to that of NaCd II 4 (PO 4 ) 3 and related to that of the mineral silicocarnotite Ca 5 (PO 4 ) 2 (SiO 4 ). Significant disorder between Li + and Cr 2+ is observed for both crystal structures. The oxidation states assigned to chromium in these two phosphates are in agreement with UV/vis/NIR absorption spectra and magnetic susceptibility data recorded for both compounds. Instead of “LiCr II PO 4 ” mixtures of LiCr II 4 (PO 4 ) 3 , Li 5 Cr II 2 Cr III (PO 4 ) 4 , Cr 2 O 3 , and CrP are observed at equilibrium. Instead of “Li 2 Cr II P 2 O 7 ” four-phase mixtures consisting of Li 9 Cr III 3 (P 2 O 7 ) 3 (PO 4 ) 2 , Li 3 Cr III 2 (PO 4 ) 3 , LiCrP 2 O 7 , and CrP were obtained. - Graphical abstract: Investigations on the equilibrium relations in the system Li/Cr/P/O revealed the two hitherto unknown phosphates Li 5 Cr II 2 Cr III (PO 4 ) 4 and LiCr II 4 (PO 4 ) 3 . They form instead of “LiCr II PO 4 ”. The crystal structures, magnetic behavior and optical spectra of these phosphates are reported. - Highlights: • The two new phosphates Li 5 Cr II 2 Cr III (PO 4 ) 4 and LiCr II 4 (PO 4 ) 3 have been characterized. • Optical spectra and paramagnetism of

Hyperenhanced Li - Li Chemonuclear Fusion

International Nuclear Information System (INIS)

Ikegami, Hidetsugu

2006-01-01

A new fusion scheme, the Li - Li chemonuclear fusion is presented, where nuclear fusion reactions are linked to atomic fusion reactions. Lithium ions are implanted on a surface of metallic Li liquid at an energy of nuclear stopping (several keV/amu). The ions collide slowly with liquid Li atoms without electronic excitation and lead to the Li - Li chemonuclear fusion through the formation of united atoms or quasi-C atoms at their turning points. Inside the quasi-atoms twin nuclei are confined within respective sub-pm scale spheres of zero-point oscillation and form themselves into ultradense intermediate nuclear complexes. Their density is million times as large as the solar interior density and close to densities of white dwarfs or white-dwarf progenitors of supernovae. This confinement of nuclear complexes is enormously prolonged towards the pycno-nuclear reactions induced by the zero-point oscillation under the presence of thermodynamic force specified by the Gibbs energy change in the quasi-atom formation in the liquid. Resulted rate enhancement of nuclear fusion by a factor of 10 48 has been anticipated. The enhancement is also argued in connection with the Bose-Einstein condensation

A method for investigation of the D(4He, γ)6Li reaction in the Ultralow energy region under a high background

Science.gov (United States)

Bystritsky, V. M.; Dudkin, G. N.; Krylov, A. R.; Gazi, S.; Huran, J.; Nechaev, B. A.; Padalko, V. N.; Sadovsky, A. B.; Tuleushev, Yu. Zh.; Filipowicz, M.; Philippov, A. V.

2016-07-01

The cosmological lithium problem, that is, a noticeable discrepancy between the predicted and observed abundances of lithium, is in conflict with the Standard Big Bang Nucleosynthesis model. For example, the abundance of 7Li is 2-4 times smaller than predicted by the Standard Big Bang Nucleosynthesis. As to the abundance of 6Li, recent more accurate optical investigations have yielded only the upper limit on the 6Li/7Li ratio, which makes the problem of 6Li abundance and accordingly of disagreement with the Standard Big Bang Nucleosynthesis predictions less acute. However, experimental study of the D(4He, γ)6Li reaction cross section is still of current importance because there is a theoretical approach predicting its anomalously large value in the region of energies below the Standard Big Bang Nucleosynthesis energy. The work is dedicated to the measurement of the cross section for the D(4He, γ)6Li reaction proceeding in zirconium deuteride at the incident 4He+ion energy of 36 keV. The experiment is performed at a pulsed Hall plasma accelerator with an energy spread of 20% FWHM. A method for direct measurement of the background from the reaction chain D(4He, 4He)D→D(D, n)3He→(n, γ) and/or (n, n‧γ) ending with activation of the surrounding material by neutrons is proposed and implemented in the work. An upper limit on the D(4He, γ)6Li reaction cross section σ≤7·10-36 cm2 at the 90% confidence level is obtained.

Intermetallic and metal-rich phases in the system Li-Ba-In-N

International Nuclear Information System (INIS)

Smetana, Volodymyr; Vajenine, Grigori V.; Kienle, Lorenz; Duppel, Viola; Simon, Arndt

2010-01-01

Three new intermetallic phases, BaLi 2.1 In 1.9 , BaLi 1.12 In 0.98 , and BaLi 1.06 In 1.16 and two subnitrides Li 35 In 45 Ba 39 N 9 and LiIn 2 Ba 3 N 0.83 have been synthesized and their crystal structures have been determined. According to single crystal X-ray diffraction data BaLi 2.1 In 1.9 and BaLi 1.12 In 0.98 crystallize with hexagonal symmetry (BaLi 2.1 In 1.9 : P6 3 /mmc, a=10.410(2), c=8.364(2) A, Z=6, V=785.0(2) A 3 ) and BaLi 1.12 In 0.98 : P6/mmm, a=17.469(1), c=10.6409(7) A, Z=30, V=2813.5(8) A 3 ), while BaLi 1.06 In 1.16 has a rhombohedral structure (R-3c, a=18.894(3), c=85.289(17) A, Z=276, V=26368(8) A 3 ). BaLi 2.1 In 1.9 is isostructural with the known phase BaLi 4 . The phase BaLi 1.12 In 0.98 is structurally related to Na 8 K 23 Cd 12 In 48 , while BaLi 1.06 In 1.16 is isostructural with Li 33.3 Ba 13.1 Ca 3 . A sample containing structurally similar BaLi 1.12 In 0.98 and BaLi 1.02 In 1.16 was also investigated by transmission electron microscopy. Li 35 In 45 Ba 39 N 9 and LiIn 2 Ba 3 N 0.83 crystallize with tetragonal (I-42m, a=15.299(2), c=30.682(6) A, Z=2, V=7182(2) A 3 ) and cubic (Fd-3m, a=14.913(2) A, Z=8, V=3316.7(7) A 3 ) symmetry, respectively. While the first-mentioned subnitride belongs to the Li 80 Ba 39 N 9 structure type, the second extends the structural family of Ba 6 In 4.78 N 2.72 . The structural features of the new compounds are discussed in comparison to the known phases and the results of total energy calculations. - Graphical abstract: One-dimensional chain of face-sharing centered icosahedra in BaLi 2.1 In 1.9

Ab initio study of isomerism of Li2AB2 molecules and Li2AB2+ ions with 16 valent electrons

International Nuclear Information System (INIS)

Charkin, O.P.; Klimenko, N.M.; MakKi, M.L.

2000-01-01

In the framework of MP2(6-31*//HF/6-31G + ZPE(HF/6-31G*) and MP4SDTQ/6-31G*//MP2/6-31G* + ZPE(MP2/6-31G*) approximations ab initio calculations of surfaces of potential energy of molecules of lithium salts of Li 2 AB 2 (Li 2 BeO 2 , L 2 MgO 2 , Li 2 BeS 2 , Li 2 MgS 2 , Li 2 CN 2 , Li 2 SiN 2 , Li 2 CP 2 ) type and ions of Li 2 AB 2 + (Li 2 BO 2 + , Li 2 AlO 2 + , Li 2 BS 2 + , Li 2 AlS 2 + , Li 2 N 3 + , Li 2 PN 2 + , Li 2 P 3 + ) type with 16 valent electrons are done. For oxide and nitride systems global minimum corresponds to symmetric linear structure D ∞h and for their sulfide and phosphorus analogues curved plane or unplane (C 2 ) structure with bond angle φ(LBA)=90-110 Deg are preferable. Equilibrium geometric parameters, relative energies and energies of isomer decomposition, frequencies and IR-intensities of normal vibrations are determined [ru

Mechanisms of Li-projectile breakup-up

International Nuclear Information System (INIS)

Rebel, H.; Srivastava, D.K.

1990-08-01

Various experimental and theoretical features observed in recent studies of break-up of 6 Li and 7 Li projectiles in the field of atomic nuclei are discussed, in particular for the transitional energy regime of 10-30 MeV/amu. The discussion is organized as three independent lectures presented at the International School on Nuclear Physics, Kiev (UkSSR), 28 May - 8 June, 1990. After a survey on the main experimental facts and on the basic reaction mechanisms, current theoretical approaches are illustrated by an application to the analysis of elastic break-up of 156 MeV 6 Li projectiles. Finally Coulomb break-up is discussed as a novel tool of laboratory nuclear astrophysics. (orig.) [de

Expectation values of the e+Li system

International Nuclear Information System (INIS)

Mitroy, J.

2004-01-01

Close to converged energies and expectation values for e + Li are computed using a ground state wave function consisting of 1200 explicitly correlated Gaussians. The best estimate of the e + Li energy was -7.532 895 5 hartree which has a binding energy of 0.002 482 hartree against dissociation into Ps+Li + . The 2γ annihilation rate for the spin singlet state was 6.996x10 9 s -1 . The annihilation rate for the triplet state, taking into account core annihilation and the 3γ decay, was 9.36x10 6 s -1

Low-Temperature Sintering Li3Mg1.8Ca0.2NbO6 Microwave Dielectric Ceramics with LMZBS Glass

Science.gov (United States)

Wang, Gang; Zhang, Huaiwu; Liu, Cheng; Su, Hua; Jia, Lijun; Li, Jie; Huang, Xin; Gan, Gongwen

2018-05-01

Li3Mg1.8Ca0.2NbO6 ceramics doped with Li2O-MgO-ZnO-B2O3-SiO2 glass (LMZBS) were prepared via a solid-state route. The LMZBS glass effectively reduced the sintering temperature of Li3Mg1.8Ca0.2NbO6 ceramics to 950°C. The effects of the LMZBS glass on the sintering behavior, microstructures and microwave dielectric properties of Li3Mg1.8Ca0.2NbO6 ceramics are discussed in detail. Among all the LMZBS doped Li3Mg1.8Ca0.2NbO6 ceramics, the sample with 1 wt.% of LMZBS glass sintered at 950°C for 4 h exhibited good dielectric properties: ɛ r = 16.7, Q × f = 31,000 GHz (9.92 GHz), τ f = - 1.3 ppm/°C. The Li3Mg1.8Ca0.2NbO6 ceramics possessed excellent chemical compatibility with Ag electrodes, and could be applied in low temperature co-fired ceramics (LTCC) applications.

A method for investigation of the D("4He, γ)"6Li reaction in the Ultralow energy region under a high background

International Nuclear Information System (INIS)

Bystritsky, V.M.; Dudkin, G.N.; Krylov, A.R.; Gazi, S.; Huran, J.; Nechaev, B.A.; Padalko, V.N.; Sadovsky, A.B.; Tuleushev, Yu.Zh.; Filipowicz, M.; Philippov, A.V.

2016-01-01

The cosmological lithium problem, that is, a noticeable discrepancy between the predicted and observed abundances of lithium, is in conflict with the Standard Big Bang Nucleosynthesis model. For example, the abundance of "7Li is 2–4 times smaller than predicted by the Standard Big Bang Nucleosynthesis. As to the abundance of "6Li, recent more accurate optical investigations have yielded only the upper limit on the "6Li/"7Li ratio, which makes the problem of "6Li abundance and accordingly of disagreement with the Standard Big Bang Nucleosynthesis predictions less acute. However, experimental study of the D("4He, γ)"6Li reaction cross section is still of current importance because there is a theoretical approach predicting its anomalously large value in the region of energies below the Standard Big Bang Nucleosynthesis energy. The work is dedicated to the measurement of the cross section for the D("4He, γ)"6Li reaction proceeding in zirconium deuteride at the incident "4He"+ion energy of 36 keV. The experiment is performed at a pulsed Hall plasma accelerator with an energy spread of 20% FWHM. A method for direct measurement of the background from the reaction chain D("4He, "4He)D→D(D, n)"3He→(n, γ) and/or (n, n′γ) ending with activation of the surrounding material by neutrons is proposed and implemented in the work. An upper limit on the D("4He, γ)"6Li reaction cross section σ≤7·10"−"3"6 cm"2 at the 90% confidence level is obtained.

Li3PO4 surface coating on Ni-rich LiNi0.6Co0.2Mn0.2O2 by a citric acid assisted sol-gel method: Improved thermal stability and high-voltage performance

Science.gov (United States)

Lee, Suk-Woo; Kim, Myeong-Seong; Jeong, Jun Hui; Kim, Dong-Hyun; Chung, Kyung Yoon; Roh, Kwang Chul; Kim, Kwang-Bum

2017-08-01

A surface coating of Li3PO4 was applied to a Ni-rich LiNi0.6Co0.2Mn0.2O2 (NCM) material to improve its thermal stability and electrochemical properties via a citric acid assisted sol-gel method. The addition of citric acid effectively suppressed the instant formation of Li3PO4 in solution, resulting in successful coating of the NCM surface. The improved thermal stability of NCM after Li3PO4 surface coating was demonstrated by differential scanning calorimetry (DSC) analysis and in situ time-resolved X-ray diffraction (TR-XRD). In particular, the TR-XRD results showed that the improved thermal stability after Li3PO4 surface coating originates from suppression of the phase transition of charged NCM at high temperatures. Furthermore, the charge-discharge tests demonstrated that Li3PO4-coated LiNi0.6Co0.2Mn0.2O2 (LP-NCM) has excellent electrochemical properties. LP-NCM exhibited a specific capacity of 192.7 mAh g-1, a capacity retention of 44.1% at 10 C, and a capacity retention of 79.7% after 100 cycles at a high cut-off voltage of 4.7 V; these values represent remarkably improved electrochemical properties compared with those of bare NCM. These improved thermal and electrochemical properties were mainly attributed to the improvement of the structural stability of the material and the suppression of the interface reaction between the cathode and the electrolyte owing to the Li3PO4 coating.

Exclusive Measurements of Breakup Reactions in the 7Li+144Sm System

International Nuclear Information System (INIS)

Heimann, D. Martinez; Pacheco, A. J.; Arazi, A.; Figueira, J. M.; Negri, A.; Capurro, O. A.; Carnelli, P.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Testoni, J. E.; Monteiro, D. S.; Niello, J. O. Fernandez; Marta, H. D.

2009-01-01

Breakup reactions induced by a 30 MeV 7 Li beam on a 144 Sm target were measured through the coincident detection of the light particles emitted in the reaction plane. The emphasis of the measurements and data analysis was placed in the complete characterization of the reaction by means of the identification of the breakup products and the experimental extraction of the physically relevant magnitudes. The coincident yield of the emitted light particles was compared with the results of kinematical calculations that were done assuming different distributions for these magnitudes and taking into account the geometric response of the detection system. The results of this comparison indicate in all cases a clear dominance of a process compatible with the breakup of 6 Li through the 3 + resonant state at 2.186 MeV following one-neutron transfer from the projectile to the target, over the breakup of the projectile itself. Relative cross sections as a function of the emission angle of the 6 Li and the in-plane anisotropy of the subsequent emission of breakup products were extracted from the data.

Nuclear charge radius of {sup 11}Li

Energy Technology Data Exchange (ETDEWEB)

Sanchez, Rodolfo, E-mail: R.Sanchez@GSI.de; Noertershaeuser, Wilfried [Gesellschaft fuer Schwerionenforschung (Germany); Dax, Andreas [CERN(Switzerland); Ewald, Guido; Goette, Stefan; Kirchner, Reinhard; Kluge, H.-Juergen; Kuehl, Thomas [Gesellschaft fuer Schwerionenforschung (Germany); Wojtaszek, Agnieszka [Swietokrzyska Academy, Institute of Physics (Poland); Bushaw, Bruce A. [Pacific Northwest National Laboratory (United States); Drake, Gordon W. F. [University of Windsor, Department of Physics (Canada); Yan Zongchao [University of New Brunswick, Department of Physics (Canada); Zimmermann, Claus [Physikalisches Institut, Eberhard Karls Universitaet Tuebingen (Germany); Albers, Daniel; Behr, John; Bricault, Pierre; Dilling, Jens; Dombsky, Marik; Lassen, Jens; Phil Levy, C. D. [Tri-University Meson Facility (Canada)

2006-07-15

We have determined the nuclear charge radius of {sup 11}Li by high-precision laser spectroscopy. The experiment was performed at the TRIUMF-ISAC facility where the {sup 7}Li-{sup 11}Li isotope shift (IS) was measured in the 2s{yields}3s electronic transition using Doppler-free two-photon spectroscopy with a relative accuracy better than 10{sup -5}. The accuracy for the IS of the other lithium isotopes was also improved. IS's are mainly caused by differences in nuclear mass, but changes in proton distribution also give small contributions. Comparing experimentally measured IS with advanced atomic calculation of purely mass-based shifts, including QED and relativistic effects, allows derivation of the nuclear charge radii. The radii are found to decrease monotonically from {sup 6}Li to {sup 9}Li, and then increase with {sup 11}Li about 11% larger than {sup 9}Li. These results are a benchmark for the open question as to whether nuclear core excitation by halo neutrons is necessary to explain the large nuclear matter radius of {sup 11}Li; thus, the results are compared with a number of nuclear structure models.

Lost in Translation (LiT): IUPHAR Review 6.

Science.gov (United States)

Dollery, Colin T

2014-05-01

Translational medicine is a roller coaster with occasional brilliant successes and a large majority of failures. Lost in Translation 1 ('LiT1'), beginning in the 1950s, was a golden era built upon earlier advances in experimental physiology, biochemistry and pharmacology, with a dash of serendipity, that led to the discovery of many new drugs for serious illnesses. LiT2 saw the large-scale industrialization of drug discovery using high-throughput screens and assays based on affinity for the target molecule. The links between drug development and university sciences and medicine weakened, but there were still some brilliant successes. In LiT3, the coverage of translational medicine expanded from molecular biology to drug budgets, with much greater emphasis on safety and official regulation. Compared with R&D expenditure, the number of breakthrough discoveries in LiT3 was disappointing, but monoclonal antibodies for immunity and inflammation brought in a new golden era and kinase inhibitors such as imatinib were breakthroughs in cancer. The pharmaceutical industry is trying to revive the LiT1 approach by using phenotypic assays and closer links with academia. LiT4 faces a data explosion generated by the genome project, GWAS, ENCODE and the 'omics' that is in danger of leaving LiT4 in a computerized cloud. Industrial laboratories are filled with masses of automated machinery while the scientists sit in a separate room viewing the results on their computers. Big Data will need Big Thinking in LiT4 but with so many unmet medical needs and so many new opportunities being revealed there are high hopes that the roller coaster will ride high again. © 2014 The British Pharmacological Society.

The electronic structure and optical properties of ABP 2O 7 ( A = Na, Li) double phosphates

Science.gov (United States)

Hizhnyi, Yu. A.; Oliynyk, A.; Gomenyuk, O.; Nedilko, S. G.; Nagornyi, P.; Bojko, R.; Bojko, V.

2008-01-01

Partial densities of states and reflection spectra of NaAlP 2O 7, KAlP 2O 7 and LiInP 2O 7 double phosphate crystals are calculated by the full-potential linear-augmented-plane-wave (FLAPW) method. Experimental reflection spectra of KAlP 2O 7, CsAlP 2O 7 and NaInP 2O 7 are measured in the 4-20 eV energy range. The values of band gaps, Eg, are found from a comparison of experiment and calculations to be 6.0 eV for NaAlP 2O 7 and KAlP 2O 7, and 4.6 eV for LiInP 2O 7.

Device fabrication, characterization, and thermal neutron detection response of LiZnP and LiZnAs semiconductor devices

Energy Technology Data Exchange (ETDEWEB)

Montag, Benjamin W., E-mail: bmontag@ksu.edu; Ugorowski, Philip B.; Nelson, Kyle A.; Edwards, Nathaniel S.; McGregor, Douglas S.

2016-11-11

Nowotny-Juza compounds continue to be explored as candidates for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present day gas-filled {sup 3}He and {sup 10}BF{sub 3} detectors. The {sup 6}Li(n,t){sup 4}He reaction yields a total Q-value of 4.78 MeV, larger than {sup 10}B, an energy easily identified above background radiations. Hence, devices fabricated from semiconductor compounds having either natural Li (nominally 7.5% {sup 6}Li) or enriched {sup 6}Li (usually 95% {sup 6}Li) as constituent atoms may provide a material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and As sealed under vacuum (10{sup −6} Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace [1]. The raw synthesized material indicated the presence high impurity levels (material and electrical property characterizations). A static vacuum sublimation in quartz was performed to help purify the synthesized material [2,3]. Bulk crystalline samples were grown from the purified material [4,5]. Samples were cut using a diamond wire saw, and processed into devices. Bulk resistivity was determined from I–V curve measurements, ranging from 10{sup 6}–10{sup 11} Ω cm. Devices were characterized for sensitivity to 5.48 MeV alpha particles, 337 nm laser light, and neutron sensitivity in a thermal neutron diffracted beam at the Kansas State University TRIGA Mark II nuclear reactor. Thermal neutron reaction product charge induction was measured with a LiZnP device, and the reaction product spectral response was observed. - Highlights: • Devices were fabricated from in-house synthesized and purified LiZnAs and LiZnP. • Devices ranged in bulk resistivity from 10{sup 6}–10{sup 11} Ω cm. • Devices showed sensitivity to 5.48 MeV alpha particles. • Devices were characterized with a 337 nm laser light. • Devices were evaluated

Elastic scattering of 7Li projectiles in the energy range of 20 to 34 MeV

International Nuclear Information System (INIS)

Khallaf, S.A.E.

1983-01-01

As far as it is known, the Watanabe folding model has not been used to analyse the elastic scattering of 7 Li projectiles. The main purpose of the present work is to calculate the differential cross sections for 7 Li elastic scattering von 90 Zr, 48 , 40 Ca, 16 O and 12 C at incident energies of 20 to 34 MeV using the Watanabe folding model and to study the applicability of this model for 7 Li elastic scattering. The potentials of 7 Li ions are revealed by Taylor expansions of alpha and triton cluster potentials. The resulting differential cross sections are compared with the predicted cross sections using phenomenological potentials of 7 Li ions. (orig./WL)

Measurement of tritium production in 6LiD irradiated with neutrons from a critical system

International Nuclear Information System (INIS)

Duan Shaojie

1998-03-01

The tritium production rate and its distribution, in a 6 LiD semisphere on a critical assembly neutron source are measured with a 6 Li sandwich gold-silicon surface barrier detector. Then tritium production rate and the average tritium production length of the neutrons in the whole 6 LiD sphere are derived from approximate sphere symmetry

Dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a {sup 209}Bi target

Energy Technology Data Exchange (ETDEWEB)

Gautam, Manjeet Singh; Vinod, K. [Indus Degree College, Department of Physics, Kinana, Jind, Haryana (India); Khatri, Hitender [Dr. B.R. Ambedekar Institute of Technology, Department of Physics, Port Blair, Andaman and Nicobar (India)

2017-10-15

The dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a common target ({sup 209}Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ({sup 209}Bi) gets suppressed at above barrier energies. In the case of the {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of {sup 6,7}Li + {sup 209}Bi reactions. In contrast to this, the observed fusion dynamics of {sup 15}N + {sup 209}Bi and {sup 16}O + {sup 209}Bi reactions, wherein

Elastic, dynamical, and electronic properties of LiHg and Li3Hg: First-principles study

Science.gov (United States)

Wang, Yan; Hao, Chun-Mei; Huang, Hong-Mei; Li, Yan-Ling

2018-04-01

The elastic, dynamical, and electronic properties of cubic LiHg and Li3Hg were investigated based on first-principles methods. The elastic constants and phonon spectral calculations confirmed the mechanical and dynamical stability of the materials at ambient conditions. The obtained elastic moduli of LiHg are slightly larger than those of Li3Hg. Both LiHg and Li3Hg are ductile materials with strong shear anisotropy as metals with mixed ionic, covalent, and metallic interactions. The calculated Debye temperatures are 223.5 K and 230.6 K for LiHg and Li3Hg, respectively. The calculated phonon frequency of the T2 g mode in Li3Hg is 326.8 cm-1. The p states from the Hg and Li atoms dominate the electronic structure near the Fermi level. These findings may inspire further experimental and theoretical study on the potential technical and engineering applications of similar alkali metal-based intermetallic compounds.

LiFePO4/polymer/natural graphite: low cost Li-ion batteries

International Nuclear Information System (INIS)

Zaghib, K.; Striebel, K.; Guerfi, A.; Shim, J.; Armand, M.; Gauthier, M

2004-01-01

The aging and performance of natural graphite/PEO-based gel electrolyte/LiFePO 4 cells are reported. The gel polymer electrolytes were produced by electron-beam irradiation and then soaked in a liquid electrolyte. The natural graphite anode in gel electrolyte containing LiBF4-EC/GBL exhibited high reversible capacity (345 mAh/g) and high coulombic efficiency (91%). The LiFePO 4 cathode in the same gel-polymer exhibited a reversible capacity of 160 mAh/g and 93% coulombic efficiency. Better performance was obtained at high-rate discharge with 6% carbon additive in the cathode, however the graphite anode performance suffers at high rate. The Li-ion gel polymer battery shows a capacity fade of 13% after 180 cycles and has poor performance at low temperature due to low diffusion of the lithium to the graphite in the GBL system. The LiFePO 4 /gel/Li system has an excellent rate capacity. LiFePO 4 cathode material is suitable for HEV application

Microscopic description of 7Li and 7Be for the DWBA treatment of cluster transfer reactions

International Nuclear Information System (INIS)

Pal, K.F.; Lovas, R.G.; Gyarmati, B.; Vertse, T.; Nagarajan, M.A.

1983-01-01

The overlap of the α-t interaction times, the 7 Li wave function with the product of the α and t wave functions, and the analogous quantity for the charge-conjugate system are calculated on microscopic grounds. This quantity contains the structure information on the 7 Li nucleus in the standard finite-range DWBA description of α and t stripping from and pick-up to 7 Li. This nucleus is described in the generator-coordinate model assuming the α+t two-cluster structure and schematic nucleon-nucleon forces. The model reproduces the measured g.s. properties reasonably. The microscopic potential overlap is obtained to be very different from those calculated with using local macroscopic α-t interactions, but the difference in the 12 C( 7 Li,t) 16 O cross section is only dramatic at backward angles. To facilitate further DWBA analyses, several versions of the potential overlap as well as the overlap without the potential are given in an easily accessible form. (author)

The 3H(α,γ)7Li reaction below Ec.m. = 1 MeV

International Nuclear Information System (INIS)

Brune, C.R.; Kavanagh, R.W.; Rolfs, C.

1993-01-01

The 3 H(α,γ) reaction, and its mirror 3 He(α,γ) are responsible for 7 Li production in the big bang. It has been demonstrated that the uncertainty in the 3 H(α,γ) reaction rate significantly affects the calculated amount of 7 Li, which is important for comparison to the observed 7 Li abundance and constraining the baryon density allowed by the standard big-bang model. Using specially prepared thin Ti- 3 H targets and an 85% high-purity germanium detector, the authors have measured the γ rays produced by the 3 H(α,γ) reaction for 50 c.m. 7 Li bound states, and angular distributions of the capture γ rays. The results are compared to previous experiments and nuclear model calculations

Catalyzed Na2LiAlH6 for hydrogen storage

International Nuclear Information System (INIS)

Ma, X.Z.; Martinez-Franco, E.; Dornheim, M.; Klassen, T.; Bormann, R.

2005-01-01

In the present study, the complex alanate Na 2 LiAlH 6 is synthesized by high-energy milling of powder blends containing NaH and LiAlH 4 . The related thermodynamics are determined. In addition, a comprehensive study was performed to investigate the influence of different oxide and halide catalysts on the kinetics of hydrogen absorption and desorption, as well as their general drawback to decrease storage capacity

Anion Redox Chemistry in the Cobalt Free 3d Transition Metal Oxide Intercalation Electrode Li[Li0.2Ni0.2Mn0.6]O2.

Science.gov (United States)

Luo, Kun; Roberts, Matthew R; Guerrini, Niccoló; Tapia-Ruiz, Nuria; Hao, Rong; Massel, Felix; Pickup, David M; Ramos, Silvia; Liu, Yi-Sheng; Guo, Jinghua; Chadwick, Alan V; Duda, Laurent C; Bruce, Peter G

2016-09-07

Conventional intercalation cathodes for lithium batteries store charge in redox reactions associated with the transition metal cations, e.g., Mn(3+/4+) in LiMn2O4, and this limits the energy storage of Li-ion batteries. Compounds such as Li[Li0.2Ni0.2Mn0.6]O2 exhibit a capacity to store charge in excess of the transition metal redox reactions. The additional capacity occurs at and above 4.5 V versus Li(+)/Li. The capacity at 4.5 V is dominated by oxidation of the O(2-) anions accounting for ∼0.43 e(-)/formula unit, with an additional 0.06 e(-)/formula unit being associated with O loss from the lattice. In contrast, the capacity above 4.5 V is mainly O loss, ∼0.08 e(-)/formula. The O redox reaction involves the formation of localized hole states on O during charge, which are located on O coordinated by (Mn(4+)/Li(+)). The results have been obtained by combining operando electrochemical mass spec on (18)O labeled Li[Li0.2Ni0.2Mn0.6]O2 with XANES, soft X-ray spectroscopy, resonant inelastic X-ray spectroscopy, and Raman spectroscopy. Finally the general features of O redox are described with discussion about the role of comparatively ionic (less covalent) 3d metal-oxygen interaction on anion redox in lithium rich cathode materials.

The frequency analysis particle resolution technique of 6LiI(Eu) scintillation detector

International Nuclear Information System (INIS)

Duan Shaojie

1995-01-01

To measure the distribution and rate of tritium production by neutron in a 6 LiD sphere, the 6 LiI(Eu) scintillation detector was used. In the measurement, the frequency analysis particle resolution technique was used. The experiment was completed perfectly

The 7Li(d-vector,n0)8Be and 7Li(d-vector,n1)8Be reactions below 160 keV

International Nuclear Information System (INIS)

Sabourov, A.; Ahmed, M. W.; Blackston, M. A.; Crowell, A. S.; Howell, C. R.; Joshi, K.; Nelson, S. O.; Perdue, B. A.; Sabourov, K.; Tonchev, A.; Weller, H. R.; Prior, R. M.; Spraker, M. C.; Braizinha, B.; Kalantar-Nayestanaki, N.

2006-01-01

The polarization observables have been determined for the 7 Li(d-vector,n 0 ) 8 Be and 7 Li(d-vector ,n 1 ) 8 Be reactions at beam energies between 80 and 160 keV. A Transition Matrix Element (TME) analysis revealed unique, dominant p-wave solutions for both neutron channels. The polarization observables were compared with distorted wave Born approximation (DWBA) and coupled reaction channels (CRC) calculations. The general features of the data can be reproduced by the CRC calculations when a large target spin-orbit interaction is included. However, serious discrepancies are observed when the TMEs of the theory and experiment are compared

Dosimetry characteristics of thermoluminescent Li2B4O7:Cu phosphor

International Nuclear Information System (INIS)

Lakshmanan, A.R.; Chandra, B.; Bhatt, R.C.

1981-01-01

Preliminary investigations on the radiation dosimetry characteristics of Li 2 B 4 O 7 :Cu TLD phosphor are described. The major TL peak in this phosphor occurs at 230 0 C and its TL sensitivity to gamma radiation is two to three times higher than that of LiF TLD-100. The gamma dose Vs TL response of this peak is linear (within +- 20%) in the dose range 0.3 mGy-3x10 2 Gy above which saturation sets in. Its TL response for 30 keV X-rays is about 20% lower than that for 60 Coγ-rays. On annealing at 300 0 C, the phosphor gets slightly discoloured (brownish). This results in the reduction of the TL sensitivity by about 20 - 25%. The phosphor does not exhibit either sensitization or damage even after a gamma dose of 10 3 Gy. The TL emission spectrum has a broad peak at 360 nm. The intrinsic TL sensitivity of virgin Li 2 B 4 O 7 :Cu to 253.7 nm UV radiation is nearly 50 times higher than that of CaSO 4 :Dy. The post-irradiation fading in Li 2 B 4 O 7 :Cu at ambient temperature and humidity conditions is, however, less than 10% in 17 days. These characteristics indicate that Li 2 B 4 O 7 :Cu is a promising phosphor for ionizing as well as UV radiation dosimetry. (author)

Influence of the α-d motion in 6Li on Trojan horse applications

International Nuclear Information System (INIS)

Pizzone, R.G.; Spitaleri, C.; Cherubini, S.; La Cognata, M.; Lamia, L.; Musumarra, A.; Romano, S.; Tumino, A.; Tudisco, S.; Miljanic, D.; Typel, S.

2005-01-01

The α-d cluster structure of 6 Li has been extensively investigated in the past few decades. In particular the width of the α momentum distribution in 6 Li has been studied as a function of the transferred momentum. These investigations are now reviewed and updated after recent experiments. Trojan horse method applications are also discussed because the momentum distribution of the spectator particle inside the Trojan horse nucleus is a necessary input for this method. The impact of the width (FWHM) variation in the extraction of the astrophysical S(E) factor is discussed for the 6 Li(d,α) 4 He reaction

Magnetic properties of the Tb4 + ion in Li2TbF6

Science.gov (United States)

Guillot, M.; El-Ghozzi, M.; Avignant, D.; Ferey, G.

1993-05-01

Both oxygen and fluorine have a partiality towards the stabilization of high oxidation states of rare earths such as Ce, Pr, and Tb. During the study of the MF-M'F4 (M=alkaline metal; M' rare ion) the compound Li2TbF6 was found to constitute the only representative obtained under ambient pressure of a structural type, namely α-Li2ZrF6, known until now only through the high pressure form. Magnetic measurements were carried out over the 1.4-300 K temperature range in continuous magnetic fields up to 20 T produced by a Bitter magnet. At low temperature and in H higher than 15 T, the magnetization M was observed to be field independent and very close to the calculated Tb4+ free ion value, i.e., 7μB; on the other hand, the data do not present any departure from the Brillouin function of the pure 8S7/2 state. The reciprocal magnetic susceptibility obeys a Curie-Weiss law leading to an effective moment of 7.86μB. A very unusual behavior of the terbium ion which presents a 4+ oxidation state is concluded: to the best of our knowledge, it is the first observation of this form. The so-found spherical 4f7 electronic configuration is the most compatible with the high coordination number of eight. Finally, the discussion within the series Li2MIVF6 compounds to understand the influence of both electronic configuration and size effects is presented.

Synthesis and structural characterization of Li{sub 3}K{sub 3}Eu{sub 7}(BO{sub 3}){sub 9}

Energy Technology Data Exchange (ETDEWEB)

Braeuchle, Sebastian; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Seibald, Markus [OSRAM GmbH, Schwabmuenchen (Germany). Corporate Innovation

2017-07-01

Li{sub 3}K{sub 3}Eu{sub 7}(BO{sub 3}){sub 9} was prepared by high-temperature solid state synthesis at 900 C in a platinum crucible from lithium carbonate, potassium carbonate, boric acid, and europium(III) oxide. The title compound crystallizes in the orthorhombic space group Pca2{sub 1} (no. 29) (Z = 4). The structure was refined from single-crystal X-ray diffraction data: a = 21.126(2), b = 6.502(2), c = 17.619(2) Aa, V = 2420.1(2) Aa{sup 3}, R1 = 0.0183 and wR2 = 0.0412 for all data. The crystal structure of Li{sub 3}K{sub 3}Eu{sub 7}(BO{sub 3}){sub 9} is isotypic to Li{sub 3}K{sub 3}Y{sub 7}(BO{sub 3}){sub 9} featuring isolated BO{sub 3} units and LiO{sub 6} octahedra forming [Li{sub 3}B{sub 4}O{sub 21}] units in the ac plane, which are linked by additional BO{sub 3} units. The K{sup +} and Eu{sup 3+} cations are arranged in the cavities of the structure.

Gamma-delayed deuteron emission of the 6Li(0+;T=1) halo state

International Nuclear Information System (INIS)

Tursunov, E.M.; Descouvemont, P.; Baye, D.

2007-01-01

M1 transitions from the 6 Li(0 + ;T=1) state at 3.563 MeV to the 6 Li(1 + ) ground state and to the α+d continuum are studied in a three-body model. The bound states are described as an α+n+p system in hyperspherical coordinates on a Lagrange mesh. The ground-state magnetic moment and the gamma width of the 6 Li(0 + ) resonance are well reproduced. The halo-like structure of the 6 Li(0 + ) resonance is confirmed and is probed by the M1 transition probability to the α+d continuum. The spectrum is sensitive to the description of the α+d phase shifts. The corresponding gamma width is around 1.0 meV, with optimal potentials. Charge symmetry is analyzed through a comparison with the β-delayed deuteron spectrum of 6 He. In 6 He, a nearly perfect cancellation effect between short-range and halo contributions was found. A similar analysis for the 6 Li(0 + ;T=1)γ decay is performed; it shows that charge-symmetry breaking at large distances, due to the different binding energies and to different charges, reduces this effect. The present branching ratio Γ γ (0 + →α+d)/Γ γ (0 + →1 + )∼1.3x10 -4 should be observable with current experimental facilities.

Dielectric properties of Li doped Li-Nb-O thin films

Energy Technology Data Exchange (ETDEWEB)

Perentzis, G.; Horopanitis, E.E.; Papadimitriou, L. [Aristotle University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Durman, V.; Saly, V.; Packa, J. [Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovicova 3, 81219 Bratislava (Slovakia)

2007-03-15

Lithium niobate LiNbO{sub 3} was prepared as a thin film layered structure deposited on stainless steel substrate using e-gun evaporation. The Li doping was provided for by the formation of Li-Nb-O/Li/LiNb-O sandwich structure and annealing at about 250 C. AC impedance spectroscopy measurements were performed on the samples at temperatures from the interval between 28 and 165 C and in a frequency range of 10{sup -3} to 10{sup 6} Hz. Using the values Z' and Z'' at different frequencies, the dielectric parameters - parts of the complex permittivity {epsilon}' and {epsilon}'' and loss tangent tan {delta} were calculated. The results prove validity of the proposed equivalent circuit containing parallel RC elements connected in series where the first RC element represents the bulk of material and the second RC element belongs to the double layer at the metal interface. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Triple-differential cross section of the 208Pb(6Li, αd)208 Pb Coulomb breakup and astrophysical S-factor of the d(α,γ)6 Li reaction at extremely low energies

International Nuclear Information System (INIS)

Igamov, S.B.; Yarmukhamedov, R.

1999-10-01

A method of calculation of the triple-differential cross section of the 208 Pb( 6 Li, αd) 208 Pb Coulomb breakup at astrophysically relevant energies E of the relative motion of the breakup fragments, taking into account the three-body (α - d - 208 Pb) Coulomb effects and the contributions from the E1- and E2- multipoles, including their interference, has been proposed. The new results for the astrophysical S-factor of the direct radiative capture d(α, γ) 6 Li reaction at E ≤ 250 keV have been obtained. It is shown that the experimental triple-differential cross section of the 208 Pb( 6 Li, αd) 208 Pb Coulomb breakup can also be used to give information about the value of the modulus squared of the nuclear vertex constant for the virtual 6 Li → α + d. (author)

The effect of Li2CO3 substitution on synthesis of LiBOB compounds as salt of electrolyte battery lithium ion

Science.gov (United States)

Lestariningsih, Titik; Wigayati, Etty Marty; Sabrina, Qolby; Prihandoko, Bambang; Priyono, Slamet

2018-04-01

Development of the synthesis of LiB(C2O4)2 compounds continues to evolve along with the need for electrolyte salts to support the research of the manufacture of lithium ion batteries. A study had been conducted on the effect of Li2CO3 substitution on the synthesis of LiB(C2O4)2 or LiBOB compounds. LiBOB was a major candidate to replace LiPF6 as a highly toxic lithium battery electrolyte and harmful to human health. Synthesis of Lithium bis(oxalato) borate used powder metallurgy method. The raw materials used are H2C2O4.2H2O, Li2CO3 or LiOH and H2BO3 from Merck Germany products. The materials are mixed with 2: 1: 1 mol ratio until homogeneous. The synthesis of LiBOB refers to previous research, where the heating process was done gradually. The first stage heating is carried out at 120°C for 4 hours, then the next stage heating is carried out at 240°C for 7 hours. The sample variation in this study was to distinguish the lithium source from Li2CO3 and LiOH. Characterization was done by XRD to know the phase formed, FTIR to confirm that functional group of LiB(C2O4)2 compound, SEM to know the morphological structure, and TG/DTA to know the thermal properties. The results of the analysis shows that LiBOB synthesis using Lithium source from Li2CO3 has succeeded to form LiBOB compound with more LiBOB phase composition is 59.1% and 40.9% LiBOB hydrate phase, SEM morphology shows powder consist of elongated round particle porous and similar to LiBOB commercial and show higher thermal stability.

Structure and stability of small Li2 +(X2Σ+ g )-Xen (n = 1-6) clusters

Science.gov (United States)

Saidi, Sameh; Ghanmi, Chedli; Berriche, Hamid

2014-04-01

We have studied the structure and stability of the Li2 +(X2Σ+ g )Xe n ( n = 1-6) clusters for special symmetry groups. The potential energy surfaces of these clusters, are described using an accurate ab initio approach based on non-empirical pseudopotential, parameterized l-dependent polarization potential and analytic potential forms for the Li+Xe and Xe-Xe interactions. The pseudopotential technique has reduced the number of active electrons of Li2 +(X2Σ+ g )-Xe n ( n = 1-6) clusters to only one electron, the Li valence electron. The core-core interactions for Li+Xe are included using accurate CCSD(T) potential fitted using the analytical form of Tang and Toennies. For the Xe-Xe potential interactions we have used the analytical form of Lennard Jones (LJ6 - 12). The potential energy surfaces of the Li2 +(X2Σ+ g )Xe n ( n = 1-6) clusters are performed for a fixed distance of the Li2 +(X2Σ+ g ) alkali dimer, its equilibrium distance. They are used to extract information on the stability of the Li2 +(X2Σ+ g Xe n ( n = 1-6) clusters. For each n, the stability of the different isomers is examined by comparing their potential energy surfaces. Moreover, we have determined the quantum energies ( D 0), the zero-point-energies (ZPE) and the ZPE%. To our best knowledge, there are neither experimental nor theoretical works realized for the Li2 +(X2Σ+ g Xe n ( n = 1-6) clusters, our results are presented for the first time.

Modeling the degradation mechanisms of C6/LiFePO4 batteries

NARCIS (Netherlands)

Li, D.; Danilov, D.L.; Zwikirsch, B.; Fichtner, M.; Yang, Y.; Eichel, R.A.; Notten, P.H.L.

2018-01-01

A fundamental electrochemical model is developed, describing the capacity fade of C6/LiFePO4 batteries as a function of calendar time and cycling conditions. At moderate temperatures the capacity losses are mainly attributed to Li immobilization in Solid-Electrolyte-Interface (SEI) layers at the

Na-Li-[V3O8] insertion electrodes: Structures and diffusion pathways

International Nuclear Information System (INIS)

Schindler, Michael; Hawthorne, Frank C.; Alexander, Malcolm A.; Kutluoglu, Rory A.; Mandaliev, Petre; Halden, Norman M.; Mitchell, Roger H.

2006-01-01

The potential insertion-electrode compounds Na 1.2 [V 3 O 8 ] (NaV) and Na 0.7 Li 0.7 [V 3 O 8 ] (NaLiV) were synthesized from mixtures of Na 2 CO 3 , Li 2 CO 3 and V 2 O 5 , which were melted at 750 o and subsequently cooled to room temperature. The structures of NaV and LiV contain sheets of polymerized (VO n ) polyhedra, which are topologically identical to the sheet of polymerized polyhedra in Li 1.2 [V 3 O 8 ] (LiV). Vanadium occurs in three different coordination environments: [2+3] V(1), [2+2+2] V(2) and [1+4+1] V(3). Calculated bond-valence sums indicate that V 4+ occurs preferentially at the V(3) site, which agrees with the general observation that [6]-coordinated V 4+ prefers [1+4+1]-rather than [2+2+2]-coordination. The M-cations Na and Li occur at three distinct sites, M(1), M(2) and M(3) between the vanadate sheets. The M(1)-site is fully occupied and has octahedral coordination. The M(2) sites are partly occupied in NaV and NaLiV, in which they occur in [4]- and [6]-coordination, respectively. Li partly occupies the M(3) site in NaLiV, in which it occurs in [3]-coordination. The M(2) and M(3) sites in NaLiV occur closer to the vanadate sheets than the M(2) sites in NaV and LiV. The shift in these cation positions is a result of the larger distance between the vanadate sheets in NaLiV than in LiV, which forces interstitial Li to move toward one of the vanadate sheets to satisfy its coordination requirements. Bond-valence maps for the interstitial cations Na and Li are presented for NaV, NaLiV and LiV. These maps are used to determine other potential cation positions in the interlayer and to map the regions of the structure where the Na and Li have their bond-valence requirements satisfied. These regions are potential pathways for Na and Li diffusion in these structures, and are used to explain chemical diffusion properties of Na and Li in the Na-Li-[V 3 O 8 ] compounds. - Graphical abstract: Bond-valence map for Li in Na 0.7 Li 0.7 [V 3 O 8 ]. Contour

Fabrication of Li-intercalated bilayer graphene

Directory of Open Access Journals (Sweden)

K. Sugawara

2011-06-01

Full Text Available We have succeeded in fabricating Li-intercalated bilayer graphene on silicon carbide. The low-energy electron diffraction from Li-deposited bilayer graphene shows a sharp 3×3R30° pattern in contrast to Li-deposited monolayer graphene. This indicates that Li atoms are intercalated between two adjacent graphene layers and take the same well-ordered superstructure as in bulk C6Li. The angle-resolved photoemission spectroscopy has revealed that Li atoms are fully ionized and the π bands of graphene are systematically folded by the superstructure of intercalated Li atoms, producing a snowflake-like Fermi surface centered at the Γ point. The present result suggests a high potential of Li-intercalated bilayer graphene for application to a nano-scale Li-ion battery.

The solubility and site preference of Fe3+ in Li7-3xFexLa3Zr2O12 garnets

Science.gov (United States)

Rettenwander, D.; Geiger, C. A.; Tribus, M.; Tropper, P.; Wagner, R.; Tippelt, G.; Lottermoser, W.; Amthauer, G.

2015-10-01

A series of Fe3+-bearing Li7La3Zr2O12 (LLZO) garnets was synthesized using solid-state synthesis methods. The synthetic products were characterized compositionally using electron microprobe analysis and inductively coupled plasma optical emission spectroscopy (ICP-OES) and structurally using X-ray powder diffraction and 57Fe Mössbauer spectroscopy. A maximum of about 0.25 Fe3+ pfu could be incorporated in Li7-3xFexLa3Zr2O12 garnet solid solutions. At Fe3+ concentrations lower than about 0.16 pfu, both tetragonal and cubic garnets were obtained in the synthesis experiments. X-ray powder diffraction analysis showed only a garnet phase for syntheses with starting materials having intended Fe3+ contents lower than 0.52 Fe3+ pfu. Back-scattered electron images made with an electron microprobe also showed no phase other than garnet for these compositions. The lattice parameter, a0, for all solid-solution garnets is similar with a value of a0≈12.98 Å regardless of the amount of Fe3+. 57Fe Mössbauer spectroscopic measurements indicate the presence of poorly- or nano-crystalline FeLaO3 in syntheses with Fe3+ contents greater than 0.16 Fe3+ pfu. The composition of different phase pure Li7-3xFexLa3Zr2O12 garnets, as determined by electron microprobe (Fe, La, Zr) and ICP-OES (Li) measurements, give Li6.89Fe0.03La3.05Zr2.01O12, Li6.66Fe0.06La3.06Zr2.01O12, Li6.54Fe0.12La3.01Zr1.98O12, and Li6.19Fe0.19La3.02Zr2.04O12. The 57Fe Mössbauer spectrum of cubic Li6.54Fe0.12La3.01Zr1.98O12 garnet indicates that most Fe3+ occurs at the special crystallographic 24d position, which is the standard tetrahedrally coordinated site in garnet. Fe3+ in smaller amounts occurs at a general 96h site, which is only present for certain Li-oxide garnets, and in Li6.54Fe0.12La3.01Zr1.98O12 this Fe3+ has a distorted 4-fold coordination.

Structural and thermodynamic similarities of phases in the Li-Tt (Tt = Si, Ge) systems: redetermination of the lithium-rich side of the Li-Ge phase diagram and crystal structures of Li17Si4.0-xGex for x = 2.3, 3.1, 3.5, and 4 as well as Li4.1Ge.

Science.gov (United States)

Zeilinger, Michael; Fässler, Thomas F

2014-10-28

A reinvestigation of the lithium-rich section of the Li-Ge phase diagram reveals the existence of two new phases, Li17Ge4 and Li4.10Ge (Li16.38Ge4). Their structures are determined by X-ray diffraction experiments of large single crystals obtained from equilibrated melts with compositions Li95Ge5 and Li85Ge15. Excess melt is subsequently removed through isothermal centrifugation at 400 °C and 530 °C, respectively. Li17Ge4 crystallizes in the space group F4[combining macron]3m (a = 18.8521(3) Å, V = 6700.1(2) Å(3), Z = 20, T = 298 K) and Li4.10Ge (Li16.38Ge4) in Cmcm (a = 4.5511(2) Å, b = 22.0862(7) Å, c = 13.2751(4) Å, V = 1334.37(8) Å(3), Z = 16, T = 123 K). Both phases are isotypic with their Si counterparts and are further representative of the Li17Pb4 and Li4.11Si structure types. Additionally, the solid solutions Li17Si4-xGex follows Vegard's law. A comparison of the GeLin coordination polyhedra shows that isolated Ge atoms are 13- and 14-coordinated in Li17Ge4, whereas in Li16.38Ge4 the Ge atoms possess coordination numbers 12 and 13. Regarding the thermodynamic stability, Li16.38Ge4 is assigned a high-temperature phase existing between ∼400 °C and 627 °C, whereas Li17Ge4 decomposes peritectically at 520-522 °C. Additionally, the decomposition of Li16.38Ge4 below ∼400 °C was found to be very sluggish. These findings are manifested by differential scanning calorimetry, long-term annealing experiments and the results from melt equilibration experiments. Interestingly, the thermodynamic properties of the lithium-rich tetrelides Li17Tt4 and Li4.1Tt (Li16.4Tt4) are very similar (Tt = Si, Ge). Besides Li15Tt4, Li14Tt6, Li12Tt7, and LiTt, the title compounds are further examples of isotypic tetrelides in the systems Li-Tt.

Breakup coupling effects on near-barrier quasi-elastic scattering of 6,7Li on 144Sm

International Nuclear Information System (INIS)

Otomar, D. R.; Lubian, J.; Gomes, P. R. S.; Monteiro, D. S.; Capurro, O. A.; Arazi, A.; Figueira, J. M.; Marti, G. V.; Heimann, D. Martinez; Negri, A. E.; Pacheco, A. J.; Niello, J. O. Fernandez; Guimaraes, V.; Chamon, L. C.

2009-01-01

Excitation functions of quasi-elastic scattering at backward angles have been measured for the 6,7 Li+ 144 Sm systems at near-barrier energies, and fusion barrier distributions have been extracted from the first derivatives of the experimental cross sections with respect to the bombarding energies. The data have been analyzed in the framework of continuum discretized coupled-channel calculations, and the results have been obtained in terms of the influence exerted by the inclusion of different reaction channels, with emphasis on the role played by the projectile breakup.

NASA Goddards LiDAR, Hyperspectral and Thermal (G-LiHT) Airborne Imager

Science.gov (United States)

Cook, Bruce D.; Corp, Lawrence A.; Nelson, Ross F.; Middleton, Elizabeth M.; Morton, Douglas C.; McCorkel, Joel T.; Masek, Jeffrey G.; Ranson, Kenneth J.; Ly, Vuong; Montesano, Paul M.

2013-01-01

The combination of LiDAR and optical remotely sensed data provides unique information about ecosystem structure and function. Here, we describe the development, validation and application of a new airborne system that integrates commercial off the shelf LiDAR hyperspectral and thermal components in a compact, lightweight and portable system. Goddard's LiDAR, Hyperspectral and Thermal (G-LiHT) airborne imager is a unique system that permits simultaneous measurements of vegetation structure, foliar spectra and surface temperatures at very high spatial resolution (approximately 1 m) on a wide range of airborne platforms. The complementary nature of LiDAR, optical and thermal data provide an analytical framework for the development of new algorithms to map plant species composition, plant functional types, biodiversity, biomass and carbon stocks, and plant growth. In addition, G-LiHT data enhance our ability to validate data from existing satellite missions and support NASA Earth Science research. G-LiHT's data processing and distribution system is designed to give scientists open access to both low- and high-level data products (http://gliht.gsfc.nasa.gov), which will stimulate the community development of synergistic data fusion algorithms. G-LiHT has been used to collect more than 6,500 km2 of data for NASA-sponsored studies across a broad range of ecoregions in the USA and Mexico. In this paper, we document G-LiHT design considerations, physical specifications, instrument performance and calibration and acquisition parameters. In addition, we describe the data processing system and higher-level data products that are freely distributed under NASA's Data and Information policy.

Investigation of large α production in reactions involving weakly bound 7Li

Science.gov (United States)

Pandit, S. K.; Shrivastava, A.; Mahata, K.; Parkar, V. V.; Palit, R.; Keeley, N.; Rout, P. C.; Kumar, A.; Ramachandran, K.; Bhattacharyya, S.; Nanal, V.; Palshetkar, C. S.; Nag, T. N.; Gupta, Shilpi; Biswas, S.; Saha, S.; Sethi, J.; Singh, P.; Chatterjee, A.; Kailas, S.

2017-10-01

The origin of the large α -particle production cross sections in systems involving weakly bound 7Li projectiles has been investigated by measuring the cross sections of all possible fragment-capture as well as complete fusion using the particle-γ coincidence, in-beam, and off-beam γ -ray counting techniques for the 7Li+93Nb system at near Coulomb barrier energies. Almost all of the inclusive α -particle yield has been accounted for. While the t -capture mechanism is found to be dominant (˜70 % ), compound nuclear evaporation and breakup processes contribute ˜15 % each to the inclusive α -particle production in the measured energy range. Systematic behavior of the t capture and inclusive α cross sections for reactions involving 7Li over a wide mass range is also reported.

Unified description of ^{6}Li structure and deuterium-^{4}He dynamics with chiral two- and three-nucleon forces.

Science.gov (United States)

Hupin, Guillaume; Quaglioni, Sofia; Navrátil, Petr

2015-05-29

We provide a unified ab initio description of the ^{6}Li ground state and elastic scattering of deuterium (d) on ^{4}He (α) using two- and three-nucleon forces from chiral effective field theory. We analyze the influence of the three-nucleon force and reveal the role of continuum degrees of freedom in shaping the low-lying spectrum of ^{6}Li. The calculation reproduces the empirical binding energy of ^{6}Li, yielding an asymptotic D- to S-state ratio of the ^{6}Li wave function in the d+α configuration of -0.027, in agreement with a determination from ^{6}Li-^{4}He elastic scattering, but overestimates the excitation energy of the 3^{+} state by 350 keV. The bulk of the computed differential cross section is in good agreement with data. These results endorse the application of the present approach to the evaluation of the ^{2}H(α,γ)^{6}Li radiative capture, responsible for the big-bang nucleosynthesis of ^{6}Li.

Data for the neutron interactions with 6Li and 10B

International Nuclear Information System (INIS)

Poenitz, W.P.

1984-01-01

The 10 B(n,α), 10 B(n,α 1 ) and, increasingly in more recent measurement, the 6 Li(n,α) cross sections are the major references used in low energy experiments. Many data from modern measurements are available for the neutron interaction with 6 Li, including total, scattering, and absolute and relative (n,α) cross sections. A consensus has been reached with these new 6 Li + n data. In contrast, the data base for the 10 B neutron interaction cross sections is unfortunately poor. This is even the case for the total cross section which is supposed to be the easiest quantity to be measured. The most serious deficiency is the absence of data from absolute measurements of the 10 B(n,α) and 10 B(n,α 1 ) cross sections in the last 10 to 15 years. The available cross section data which were used for the ENDF/B-VI evaluation will be discussed. 43 references

Investigation of the reaction 6Li + 40Ca at 156 MeV in a coincidence experiment

International Nuclear Information System (INIS)

Freindl, L.; Grotowski, K.; Uniwersytet Jagiellonski, Krakow; Planeta, R.; Klewe-Nebenius, H.; Neumann, B.; Buschmann, J.; Gils, H.J.; Rebel, H.; Zagromski, S.

1983-12-01

The cross sections for inelastic break up have been studied for the 6 Li + 40 Ca reaction at Esub(Li) = 156 MeV. For this, gamma ray spectra from the heavy residual nuclei were measured in coincidence with beam velocity projectile fragments. The cross sections were found to be: 34 +- 9 14 mb for protons, 30 +- 7 12 mb for deuterons, and 78 +- 41 142 mb for α-particles, respectively. These values are small when compared to total break up cross sections. A comparison of the cross section sum of all known reaction paths induced by 6 Li + 40 Ca at 156 MeV with total reaction cross section indicates a missing cross section of the order of a few hundred millibarns. It is discussed whether this cross section may be attributed to pick up reactions. (orig.) [de

Role of dopants in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P detectors

International Nuclear Information System (INIS)

Mohammadi, Kh.; Moussavi Zarandi, A.; Afarideh, H.; Shahmaleki, S.

2013-01-01

In this study, electronic structure of LiF crystal doped with Mg,Cu,P impurities was studied with WIEN2k code on the basis of FPLAPW+lo method. Results show that in Mg-doped LiF composition, an electronic trap was created with impurity concentration of 1.56% and 3.125%. In this condition, the electronic trap with increasing the percentage of the impurities up to 4.687% is annihilated. It was found, that by doping of Mg and Cu or P simultaneously, a hole-trap is created in valence band. It was realized that in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P, Cu impurity and Li atom, have a key role in creation of levels which lead to create electronic and hole traps. Mg impurity and F atom, only have a role in creation of electronic traps. In addition, P impurity has a main role in creation of the electronic and hole traps in LiF:Mg,Cu,P. The activation energy of electronic and hole trap in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P crystalline lattice were obtained as 0.3 and 5.5 eV, 0.92 and 3.4 eV and 0.75 and 3.1 eV, respectively. - Graphical abstract: Figure (a) and (b) shows changes in electronic structure and band gap energy of LiF crystal due to presence of Mg and Cu, Mg and P ions respectively. - Highlights: • Electronic structure of LiF, LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P materials were studied with WIEN2K code. • In LiF:Mg,Cu and LiF:Mg,Cu,P, Li atom and Cu impurity have a key role in creation of levels. • F atom and Mg impurity only have a role in creation of electronic traps. • In LiF:Mg,Cu,P, P impurity has a main role in creation of electronic and hole traps

Properties of the LiCl-KCl-Li2O system as operating medium for pyro-chemical reprocessing of spent nuclear fuel

Science.gov (United States)

Mullabaev, Albert; Tkacheva, Olga; Shishkin, Vladimir; Kovrov, Vadim; Zaikov, Yuriy; Sukhanov, Leonid; Mochalov, Yuriy

2018-03-01

Crystallization temperatures (liquidus and solidus) in the LiCl-Li2O and (LiCl-KCl)-Li2O systems with the KCl content of 10 and 20 mol.% were obtained with independent methods of thermal analysis using cooling curves, isothermal saturation, and differential scanning calorimetry. The linear sweep voltammetry was applied to control the time of the equilibrium establishment in the molten system after the Li2O addition, which depended on the composition of the base melt and the concentration of Li2O. The fragments of the binary LiCl-Li2O and quazi-binary [LiCl-KCl(10 mol.%)]-Li2O and [LiCl-KCl(20 mol.%)]-Li2O phase diagrams in the Li2O concentration range from 0 to 12 mol.% were obtained. The KCl presence in the LiCl-KCl-Li2O molten mixture in the amount of 10 and 20 mol.% reduces the liquidus temperature by 30 and 80°, respectively, but the region of the homogeneous molten state of the system is considerably narrowed, which complicates its practical application. The Li2O solubility in the molten LiCl, LiCl-KCl(10 mol.%) and LiCl-KCl(20 mol.%) decreases with increasing the KCl content and is equal to 11.5, 7.7 and 3.9 mol.% at 650°С, respectively. The LiCl-KCl melt with 10 mol.% KCl can be recommended for practical use as a medium for the SNF pyro-chemical reprocessing at temperature below 700 °C.

Development of antireflection coatings with a sup 6 LiF/ sup 6 sup 2 Ni multilayer converter for ultracold neutron detectors

CERN Document Server

Maier-Komor, P; Bergmaier, A; Dollinger, G; Paul, S; Schott, W

2002-01-01

High efficiency detectors for ultracold neutrons (UCN) are needed at the new high flux neutron source, Forschungsreaktor Muenchen II. In the development described, silicon PIN diodes were chosen to detect the alpha-particles or the tritons created in the reaction sup 6 Li(n,alpha)t. The high reflectance of UCN on sup 6 Li with its positive optical potential must be compensated by a material with negative optical potential. The isotope sup 6 sup 2 Ni was chosen for this. To avoid problems due to chemical reactions of Li with humidity, the compound sup 6 LiF was chosen. One hundred and fifty double layers of sup 6 LiF/ sup 6 sup 2 Ni had to be deposited by physical vapor deposition on silicon PIN diodes which had already been coated with 88 nm approx 77 mu g/cm sup 2 of sup 5 sup 8 Ni for reflection of the UCN. The theoretical optimal thickness of the sup 6 sup 2 Ni layers is 3 nm, and that of sup 6 LiF is 6 nm. Since expensive isotopes were involved, a small source-to-substrate distance had to be used, but wit...

cap alpha. -transfer reactions /sup 27/Al(/sup 6/Li, d)/sup 31/P, /sup 29/Si(/sup 6/Li, d)/sup 33/S and /sup 31/P(/sup 6/Li, d)/sup 35/Cl at 36 MeV. [Angular distributions, EFR DWBA, spectroscopic strengths

Energy Technology Data Exchange (ETDEWEB)

Eswaran, M A; Gove, H E; Cook, R; Sikora, B [Rochester Univ., NY (USA). Nuclear Structure Research Lab.

1979-08-13

The ..cap alpha..-transfer reactions /sup 27/Al(/sup 6/Li,d)/sup 31/P,/sup 29/Si(/sup 6/Li,d) /sup 33/S and /sup 31/P(Li,d)/sup 35/Cl have been studied at a /sup 6/Li energy of 36 MeV. Absolute cross sections and angular distributions have been measured and an exact finite-range distorted-wave Born approximation analysis assuming a direct cluster transfer has been used to extract from the data ..cap alpha..-particle spectroscopic strengths for levels populated in /sup 31/P, /sup 33/S and /sup 35/Cl in three reactions respectively. The results show that in the case of most of the low-lying excited states of /sup 31/P a single value of L of the transferred ..cap alpha..-particle contributes, though a multiplicity of L-values are allowed by angular momentum selection rules. It is also found that the ..cap alpha..-particle spectroscopic strength of the ground state of /sup 31/P is a factor of 2 more than the strengths of the ground states of /sup 33/S and /sup 35/Cl. The ..cap alpha..-spectroscopic strengths of ground states of these, as well as other odd-A s-d shell nuclei, are compared with the presently available shell model calculations.

Towards 6Li-40K ground state molecules

International Nuclear Information System (INIS)

Brachmann, Johannes Felix Simon

2013-01-01

, thereby establishing the first observation of a many body effect in the crossover regime of a narrow Feshbach resonance. Further, mass dependent factors, with which the equilibration of an induced anisotropic temperature of the trapped particle samples can be described, are experimentally determined for the first time. The type of resonance as well as the measured molecular lifetimes are found to be very well suited for STIRAP transfer. A Raman laser system is designed based on the transition wavelengths and durations of state transfer which are predicted. As the wavelengths of the Raman lasers differ widely but coherence of the light fields is needed, the technical realization of a laser system is challenging. As a part of the laser system, the construction and characterization of a reference optical resonator are presented. Laser frequency stabilization with a linewidth of approximately 500 Hz and an Allan deviation below 10-12 for timespans up to several ten seconds are demonstrated. Further, the stabilization of a frequency comb to this reference laser is demonstrated. For the laser spectroscopy of electronically excited Li - K states an interferometric laser frequency stabilization will be used. The device is a commercial design, for which a calibration procedure that enhances the precision by several orders of magnitude is worked out within this thesis. The calibration scheme includes the precise measurement of the stabilization's wavelength dependent frequency deviations by means of a frequency comb. By the implementation of several calibration steps a remaining frequency deviation of less than 5.7 MHz (rms 1.6 MHz) in the whole relevant wavelength range 750-795 nm is achieved. Only the exceptional precision of the fully calibrated device permits the usage for the Li-K spectroscopy, while the demonstrated wide tuning capability facilitates the completion of the latter in a fast and convenient manner.

Mass of 11Li from the 1H(11Li,9Li)3H reaction

International Nuclear Information System (INIS)

Roger, T.; Savajols, H.; Mittig, W.; Caamano, M.; Roussel-Chomaz, P.; Tanihata, I.; Alcorta, M.; Bandyopadhyay, D.; Bieri, R.; Buchmann, L.; Davids, B.; Galinski, N.; Howell, D.; Mills, W.; Mythili, S.; Openshaw, R.; Padilla-Rodal, E.; Ruprecht, G.; Sheffer, G.; Shotter, A. C.

2009-01-01

The mass of 11 Li has been determined from Q-value measurements of the 1 H( 11 Li, 9 Li) 3 H reaction. The experiment was performed at TRIUMF laboratory with the GANIL active target MAYA. Energy-energy and angle-angle kinematics reconstruction give a Q value of 8.119(22) MeV for the reaction. The derived 11 Li two-neutron separation energy is S 2n =363(22) keV

Knock-on tail formation due to nuclear elastic scattering and its observation method using γ-ray-generating "6Li+d reaction in tokamak deuterium plasmas

International Nuclear Information System (INIS)

Matsuura, Hideaki; Sugiyama, Shota; Kajimoto, Shogo; Sawada, Daisuke; Nishimura, Yosuke; Kawamoto, Yasuko

2016-01-01

A knock-on tail formation in deuteron velocity distribution function due to nuclear elastic scattering (NES) by energetic protons and its observation method using γ-ray-generating "6Li(d,pγ)"7Li reaction are examined for proton-beam-injected deuterium plasmas. The proton velocity distribution function is obtained by means of the ion trajectory analysis in a Tokamak magnetic configuration. The knock-on tail in two-dimensional (2D) deuteron velocity distribution function due to NES by energetic protons is evaluated via Boltzmann collision integral and 2D Fokker-Planck simulation. From the 2D deuteron velocity distribution function obtained, enhancement of the emission rate of 0.48-MeV γ-rays by "6Li(d,p)"7Li*, "7Li*→"7Li+γ reaction due to NES is evaluated. It is shown that the γ-ray emission rate is significantly influenced by the magnitude of the knock-on tail, and the γ-ray-generating reaction can be a useful tool for the knock-on tail observation. (author)

Charge carrier density in Li-intercalated graphene

KAUST Repository

Kaloni, Thaneshwor P.; Cheng, Yingchun; Kahaly, M. Upadhyay; Schwingenschlö gl, Udo

2012-01-01

The electronic structures of bulk C 6Li, Li-intercalated free-standing bilayer graphene, and Li-intercalated bilayer and trilayer graphene on SiC(0 0 0 1) are studied using density functional theory. Our estimate of Young's modulus suggests that Li

Synthesis of Li(x)Na(2-x)Mn2S3 and LiNaMnS2 through redox-induced ion exchange reactions

International Nuclear Information System (INIS)

Luthy, Joshua A.; Goodman, Phillip L.; Martin, Benjamin R.

2009-01-01

Na 2 Mn 2 S 3 was oxidatively deintercalated using iodine in acetonitrile to yield Na 1.3 Mn 2 S 3 , with lattice constants nearly identical to that of the reactant. Lithium was then reductively intercalated into the oxidized product to yield Li 0.7 Na 1.3 Mn 2 S 3 . When heated, this metastable compound decomposed to form a new crystalline compound, LiNaMnS 2 , along with MnS and residual Na 2 Mn 2 S 3 . Single crystal X-ray diffraction structural analysis of LiNaMnS 2 revealed that this compound crystallizes in P-3m1 with cell parameters a=4.0479(6) A, c=6.7759(14) A, V=96.15(3) A 3 (Z=1, wR2=0.0367) in the NaLiCdS 2 structure-type. - Graphical abstract: Structure of LiNaMnS 2 . Li and Mn are statistically distributed in edge-shared tetrahedral environments linked into infinite planes. Sodium ions occupy interlayer sites

Effect of Heat Treatment on the Lithium Ion Conduction of the LiBH4–LiI Solid Solution

DEFF Research Database (Denmark)

Sveinbjörnsson, Dadi Þorsteinn; Mýrdal, Jón Steinar Garðarsson; Blanchard, Didier

2013-01-01

The LiBH4–LiI solid solution is a good Li+ conductor and a promising crystalline electrolyte for all-solid-state lithium based batteries. The focus of the present work is on the effect of heat treatment on the Li+ conduction. Solid solutions with a LiI content of 6.25–50% were synthesized by high...

Magnetism and structural chemistry of the n=2 Ruddlesden-Popper phase La3LiMnO7

International Nuclear Information System (INIS)

Battle, Peter D.; Burley, Jonathan C.; Gallon, Daniel J.; Grey, Clare P.; Sloan, Jeremy

2004-01-01

Polycrystalline samples of the n=2 Ruddlesden-Popper phase La 3 LiMnO 7 have been prepared and characterized. X-ray and neutron diffraction suggest that the structure is tetragonal with a disordered distribution of Li and Mn cations over the octahedral sites, but 6 Li MAS NMR shows that the Li and Mn are 1:1 ordered locally. Electron microscopy shows that the stacking of the cation-ordered, perovskite-like bilayers along the crystallographic z-axis is disordered on the distance scale sampled by X-ray and neutron diffraction. Magnetometry data and neutron diffraction data collected at 2 K together suggest that the Mn cations within each structural domain order antiferromagnetically at 14 K, but that the disorder along z prevents the establishment of long-range magnetic order

Study of the 6Li+16O light heavy-ion system around the Coulomb barrier

International Nuclear Information System (INIS)

Glasner, K.; Ricken, L.; Kuhlmann, E.

1986-01-01

Total cross sections of the light heavy-ion reactions 16 O( 6 Li,p) 21 Ne, i=0-10, have been measured for beam energies Esub(Li)=4.5-8.0 MeV in steps of 100 keV. Additional excitation functions of the inclusive reactions 16 O( 6 Li,xy), x=p, n and α, were taken for Esub(li)=4.1-12.5 MeV. The 6 Li+ 16 O reaction can be understood as a predominant compound-nucleus process as extensive Hauser-Feshbach calculations show. A comprehensive statistical analysis yields a coherence width GAMMA=130+-20 keV for Esub(x)( 22 Na)approx.=19 MeV. Statistically significant deviations from pure fluctuation phenomena are found in most excitation functions at Esub(x)( 22 Na)=17.9, 18.4, 19.2 and 20.2 MeV. Interpreting these structures with widths 400<=GAMMAsub(tot)<=800 keV as intermediate-width resonances in terms of rotational band, tentative spin assignments can be given. (orig.)

Application of the three-body model to the reactions 6Li(3He,t 3He)3He and 6Li(3He,3He3He)3H

International Nuclear Information System (INIS)

Haftel, M.I.; Allas, R.G.; Beach, L.A.; Bondelid, R.O.; Petersen, E.L.; Slaus, I.; Lambert, J.M.; Treado, P.A.

1977-01-01

Experimental and theoretical cross sections are presented for the 6 Li( 3 He, 3 He 3 He) 3 H and 6 Li( 3 He,t 3 He) 3 He reactions for the symmetric angle pairs 20 0 -20 0 , 28.3 0 -28.3 0 , and 35 0 -35 0 . The theoretical cross sections are calculated in a three-body model where the trions (i.e., mass-3 nuclei) are treated as elementary particles with 6 Li being a 3 He- 3 H bound state. The trion-trion interaction is represented by S wave separable potentials with the breakup cross sections calculated with the tree-body Haftel-Ebenhoeh code. the Coulomb interaction is taken into account by fitting the separable potential parameters to the trion-trion scattering data and is included approximately in the breakup code. The experimental cross sections are compared with both the plane-wave impulse approximation and the three-body model predictions. The plane-wave impulse approximation predicts both the shapes and magnitudes poorly (10 to 20 times experiment). Without Coulomb corrections the three-body model gives good agreement with experiment for the shapes of the spectra with the magnitudes generally being about 40% of experiment for 6 Li( 3 He, 3 He 3 He) 3 H and about 80% for 6 Li( 3 He,t 3 He) 3 He. The Coulomb corrections improve the magnitudes predicted by the three-body model but not the shapes. It is observed that for these reactions S wave separable potentials describe the breakup data much better than they do the two-body trion-trion scattering data. This result should encourage further three-body treatment of these and similar reactions

Energy dependence of the 3He(3He,π+)6Li reaction

International Nuclear Information System (INIS)

Le Bornec, Y.; Hibou, F.; Bimbot, L.; Hennino, T.; Jourdain, J.C.; Reide, F.; Tatischeff, B.; Willis, N.; Aslanides, E.; Bergdolt, G.; Fassnacht, P.; Racca, C.; Boudard, A.; Bruge, G.; Lugol, J.C.

1983-01-01

The 3 He( 3 He, π + ) 6 Li reaction has been studied as a function of energy using the 3 He beam at SATURNE. Cross sections for the 6 Li ground state (1 + ) and 2.18 MeV (3 + ) levels have been obtained at 350, 420, 500 and 600 MeV incident energies at angles THETAsub(π)(lab)=15 0 and 40 0 . These results are compared with two theoretical predictions. (orig.)

An update on the big bang nucleosynthesis prediction for 7Li: the problem worsens

International Nuclear Information System (INIS)

Cyburt, Richard H; Fields, Brian D; Olive, Keith A

2008-01-01

The lithium problem arises from the significant discrepancy between the primordial 7 Li abundance as predicted by big bang nucleosynthesis (BBN) theory and the Wilkinson Microwave Anisotropy Probe (WMAP) baryon density, and the pre-Galactic lithium abundance inferred from observations of metal-poor (Population II) stars. This problem has loomed for the past decade, with a persistent discrepancy of a factor of 2–3 in 7 Li/H. Recent developments have sharpened all aspects of the Li problem. Namely: (1) BBN theory predictions have sharpened due to new nuclear data; in particular, the uncertainty on the reaction rate for 3 He(α,γ) 7 Be has reduced to 7.4%, nearly a factor of 2 tighter than previous determinations. (2) The WMAP five-year data set now yields a cosmic baryon density with an uncertainty reduced to 2.7%. (3) Observations of metal-poor stars have tested for systematic effects. With these, we now find that the BBN+WMAP predicts 7 Li/H = (5.24 −0.67 +0.71 ) × 10 −10 . The central value represents an increase by 23%, most of which is due to the upward shift in the 3 He(α,γ) 7 Be rate. More significant is the reduction in the 7 Li/H uncertainty by almost a factor of 2, tracking the reduction in the 3 He(α,γ) 7 Be error bar. These changes exacerbate the Li problem; the discrepancy is now a factor 2.4 or 4.2σ (from globular cluster stars) to 4.3 or 5.3σ (from halo field stars). Possible resolutions to the lithium problem are briefly reviewed, and key experimental and astronomical measurements highlighted

Dosimetric characteristics of Li2B4O7:Cu,Ag,P solid TL detectors

International Nuclear Information System (INIS)

Proki, M.

2002-01-01

The main dosimetric characteristics are presented of newly prepared tissue-equivalent, highly sensitive thermoluminescent detector, Li 2 B 4 O 7 :Cu,Ag,P in the form of sintered pellets, developed at the Institute of Nuclear Sciences, Vin a . As a result of an advancement in the preparation procedure by the sensitising of basic copper activated lithium borate TL material, significant improvement in the TL sensitivity of Li 2 B 4 O 7 :Cu,Ag,P was gained. The glow curve of Li 2 B 4 O 7 :Cu,Ag,P consists of well defined main dosimetric peak situated at about 185-190 deg. C with the TL sensitivity which is about four to five times higher than that of LiF:Mg,Ti (TLD-100). From the experimental results a very wide linear dose response range, up to 10 3 Gy is evident. Dosimetric characteristics make sintered solid Li 2 B 4 O 7 :Cu,Ag,P TL detectors very promising for different dosimetry applications particularly in medical dosimetry and also for individual monitoring. (author)

7Li neutron-induced elastic scattering cross section measurement using a slowing-down spectrometer

Directory of Open Access Journals (Sweden)

Heusch M.

2010-10-01

Full Text Available A new integral measurement of the 7Li neutron induced elastic scattering cross section was determined in a wide neutron energy range. The measurement was performed on the LPSC-PEREN experimental facility using a heterogeneous graphite-LiF slowing-down time spectrometer coupled with an intense pulsed neutron generator (GENEPI-2. This method allows the measurement of the integral elastic scattering cross section in a slowing-down neutron spectrum. A Bayesian approach coupled to Monte Carlo calculations was applied to extract naturalC, 19F and 7Li elastic scattering cross sections.

Study on Stability and Electrochemical Properties of Nano-LiMn1.9Ni0.1O3.99S0.01-Based Li-Ion Batteries with Liquid Electrolyte Containing LiPF6

Directory of Open Access Journals (Sweden)

Monika Bakierska

2016-01-01

Full Text Available Herein, we report on the stability and electrochemical properties of nanosized Ni and S doped lithium manganese oxide spinel (LiMn1.9Ni0.1O3.99S0.01, LMN1OS in relation to the most commonly used electrolyte solution containing LiPF6 salt. The influence of electrochemical reaction in the presence of selected electrolyte on the LMN1OS electrode chemistry was examined. The changes in the structure, surface morphology, and composition of the LMN1OS cathode after 30 cycles of galvanostatic charging/discharging were determined. In addition, thermal stability and reactivity of the LMN1OS material towards the electrolyte system were verified. Performed studies revealed that no degradative effects, resulting from the interaction between the spinel electrode and liquid electrolyte, occur during electrochemical cycling. The LMN1OS electrode versus LiPF6-based electrolyte has been indicated as an efficient and electrochemically stable system, exhibiting high capacity, good rate capability, and excellent coulombic efficiency. The improved stability and electrochemical performance of the LMN1OS cathode material originate from the synergetic substitution of LiMn2O4 spinel with Ni and S.

Prospective conceptual qualification of hybrid centrifugation/distillator for 6LI nuclear fusion technology scaled supply demands

International Nuclear Information System (INIS)

Sedano, L.; Herranz, J. L.; Casado, J. L.; Castro, P.; Xiberta, J.

2013-01-01

The change in the demand for exploitation of lithium as a resource appears during the last decade, related to the development of the ion-Li batteries market and with the requirements of Nuclear Fusion fuels (deuterium and lithium) as coming energy option. A prospective analysis of synergistic demands of both markets, in its technical and in its economic aspects appears of prospective interest. The civil market 6 Li/ 7 Li enrichment demand is analyzed. Specific technological developments permitting on-line production according to demand is discussed. A [centrifugation /thermal diffusion / combined distillation] technique is selected and qualified as technologically viable option for scaled production of litiated-forms. A conceptual design of a production plant is finally proposed according to the new technical capability.

Lithium intercalation in the LiLaNb{sub 2}O{sub 7} perovskite structure; Intercalation du lithium dans la structure perovskite LiLaNb{sub 2}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Bohnke, C.; Bohnke, O.; Fourquet, J.L. [Universite du Maine, 72 - Le Mans (France). Laboratoire des Fluorures

1996-12-31

ABO{sub 3} perovskite-type oxides having vacancies in the A-sites of their structure are interesting candidates for solid electrolytes when their A-sites are occupied by Li{sup +} ions having a high mobility. This is the case with the [Li{sub 3x}La{sub 2/3-x}]TiO{sub 3} solid solution compound which has a 10{sup -3} S cm{sup -1} ionic conductivity at ambient temperature. Electrochemical intercalation in this material is possible thanks to the presence of Ti{sup 4+} but the small amount of vacancies (0.33 maximum) leads to a low intercalation rate. In order to solve this problem, the LiLaNb{sub 2}O{sub 7} material which has a greater amount of vacancies has been studied and the results relative to the electrochemical intercalation of lithium in this perovskite are presented. The thermodynamical and kinetics properties of the lithium intercalation reaction have been studied by intermittent galvano-static discharges and impedance spectroscopy in LiClO{sub 4}-propylene carbonate medium. (J.S.) 7 refs.

Lithium intercalation in the LiLaNb{sub 2}O{sub 7} perovskite structure; Intercalation du lithium dans la structure perovskite LiLaNb{sub 2}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Bohnke, C; Bohnke, O; Fourquet, J L [Universite du Maine, 72 - Le Mans (France). Laboratoire des Fluorures

1997-12-31

ABO{sub 3} perovskite-type oxides having vacancies in the A-sites of their structure are interesting candidates for solid electrolytes when their A-sites are occupied by Li{sup +} ions having a high mobility. This is the case with the [Li{sub 3x}La{sub 2/3-x}]TiO{sub 3} solid solution compound which has a 10{sup -3} S cm{sup -1} ionic conductivity at ambient temperature. Electrochemical intercalation in this material is possible thanks to the presence of Ti{sup 4+} but the small amount of vacancies (0.33 maximum) leads to a low intercalation rate. In order to solve this problem, the LiLaNb{sub 2}O{sub 7} material which has a greater amount of vacancies has been studied and the results relative to the electrochemical intercalation of lithium in this perovskite are presented. The thermodynamical and kinetics properties of the lithium intercalation reaction have been studied by intermittent galvano-static discharges and impedance spectroscopy in LiClO{sub 4}-propylene carbonate medium. (J.S.) 7 refs.

Nuclear charge radii of 8,9Li determined by laser spectroscopy

International Nuclear Information System (INIS)

Ewald, G.; Dax, A.; Goette, S.; Kirchner, R.; Kluge, H.J.; Kuehl, T.; Sanchez, R.; Wojtaszek, A.; Noertershaeuser, W.; Drake, G.W.F.; Yan, Z.C.; Zimmermann, C.

2004-06-01

The 2S → 3S transition of 6,7,8,9 Li was studied by high-resolution laser spectroscopy using two-photon Doppler-free excitation and resonance-ionization detection. The hyperfine structure splitting and the isotope shift were determined with precision at the 100 kHz level. Combined with recent theoretical work, the changes in nuclear charge radii of 8,9 Li were determined. These are now the lightest short-lived isotopes for which the charge radii have been measured. It is found that the charge radii monotonically decrease with increasing neutron number from 6 Li to 9 Li. (orig.)

Study of the unbound nuclei 7,9He and 10Li

International Nuclear Information System (INIS)

Al Falou, H.

2007-07-01

The unbound nuclei 7,9 He and 10 Li have been investigated via the high-energy breakup of beams of neutron-rich nuclei ( 8 He, 11 Be and 14 B). The decay-energy spectra were reconstructed from coincident measurements of the charged fragments ( 6,8 He and 9 Li) with a ΔE-E telescope (CHARISSA) and the neutrons with the DEMON array. A theoretical approach based on the sudden approximation was used to model the reactions populating the unbound final states. The calculated decay-energy spectra were convoluted with the response function of the experimental setup using a simulation developed specifically for the present study and compared with the experimental results. The 10 Li system was produced using an 11 Be beam and the results confirm the continuation of the inversion of the ν1s1/2 and ν0p1/2 levels in the N = 7 isotopic chain. The 9 He system was produced in two different ways with the breakup of 11 Be and 14 B, and was the most exotic system studied here. In this case, a structure was observed at very low decay energy which very probably corresponds to a virtual s state (a s ≅ -2 - 0 fm). This result suggests that the level inversion also occurs in 9 He, but with a much weaker core-neutron interaction than for 10 Li (a s equals -14 ± 2 fm). For the data acquired from the breakup of the 14 B beam, the decay energy spectrum exhibits a resonance around E r equals 1.2 MeV, which most probably corresponds to an excited 1/2 - state in 9 He. The 7 He system was investigated with three different beams ( 8 He, 11 Be and 14 B). No evidence for the existence of the proposed low-lying (E r ∼ 1 MeV) spin-orbit partner (1/2 - ) of the ground state (3/2 - ) could be found. (author)

A method for investigation of the D({sup 4}He, γ){sup 6}Li reaction in the Ultralow energy region under a high background

Energy Technology Data Exchange (ETDEWEB)

Bystritsky, V.M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Dudkin, G.N. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Krylov, A.R. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Gazi, S.; Huran, J. [Institute of Electrical Engineering, Slovak Academy of Sciences, Bratislava (Slovakia); Nechaev, B.A.; Padalko, V.N. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Sadovsky, A.B. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Tuleushev, Yu.Zh. [Institute of Nuclear Physics, Ministry of Power Engineering, Almaty (Kazakhstan); Filipowicz, M. [Faculty of Energy and Fuels, University of Science and Technologies, Krakow (Poland); Philippov, A.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2016-07-21

The cosmological lithium problem, that is, a noticeable discrepancy between the predicted and observed abundances of lithium, is in conflict with the Standard Big Bang Nucleosynthesis model. For example, the abundance of {sup 7}Li is 2–4 times smaller than predicted by the Standard Big Bang Nucleosynthesis. As to the abundance of {sup 6}Li, recent more accurate optical investigations have yielded only the upper limit on the {sup 6}Li/{sup 7}Li ratio, which makes the problem of {sup 6}Li abundance and accordingly of disagreement with the Standard Big Bang Nucleosynthesis predictions less acute. However, experimental study of the D({sup 4}He, γ){sup 6}Li reaction cross section is still of current importance because there is a theoretical approach predicting its anomalously large value in the region of energies below the Standard Big Bang Nucleosynthesis energy. The work is dedicated to the measurement of the cross section for the D({sup 4}He, γ){sup 6}Li reaction proceeding in zirconium deuteride at the incident {sup 4}He{sup +}ion energy of 36 keV. The experiment is performed at a pulsed Hall plasma accelerator with an energy spread of 20% FWHM. A method for direct measurement of the background from the reaction chain D({sup 4}He, {sup 4}He)D→D(D, n){sup 3}He→(n, γ) and/or (n, n′γ) ending with activation of the surrounding material by neutrons is proposed and implemented in the work. An upper limit on the D({sup 4}He, γ){sup 6}Li reaction cross section σ≤7·10{sup −36} cm{sup 2} at the 90% confidence level is obtained.

Population of Nuclei Via 7Li-Induced Binary Reactions

International Nuclear Information System (INIS)

Clark, Rodney M.; Phair, Larry W.; Descovich, M.; Cromaz, Mario; Deleplanque, M.A.; Fall on, Paul; Lee, I-Yang; Macchiavelli, A.O.; McMahan, Margaret A.; Moretto, Luciano G.; Rodriguez-Vieitez, E.; Sinha, Shrabani; Stephens, Frank S.; Ward, David; Wiedeking, Mathis

2005-01-01

The authors have investigated the population of nuclei formed in binary reactions involving 7 Li beams on targets of 160 Gd and 184 W. The 7 Li + 184 W data were taken in the first experiment using the LIBERACE Ge-array in combination with the STARS Si ΔE-E telescope system at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. By using the Wilczynski binary transfer model, in combination with a standard evaporation model, they are able to reproduce the experimental results. This is a useful method for predicting the population of neutron-rich heavy nuclei formed in binary reactions involving beams of weakly bound nuclei formed in binary reactions involving beams of weakly bound nuclei and will be of use in future spectroscopic studies

Complex Diffusion Mechanisms for Li in Feldspar: Re-thinking Li-in-Plag Geospeedometry

Science.gov (United States)

Holycross, M.; Watson, E. B.

2017-12-01

In recent years, the lithium isotope system has been applied to model processes in a wide variety of terrestrial environments. In igneous settings, Li diffusion gradients have been frequently used to time heating episodes. Lithium partitioning behavior during decompression or cooling events drives Li transfer between phases, but the extent of Li exchange may be limited by its diffusion rate in geologic materials. Lithium is an exceptionally fast diffuser in silicate media, making it uniquely suited to record short-lived volcanic phenomena. The Li-in-plagioclase geospeedometer is often used to time explosive eruptions by applying laboratory-calibrated Li diffusion coefficients to model concentration profiles in magmatic feldspar samples. To quantify Li transport in natural scenarios, experimental measurements are needed that account for changing temperature and oxygen fugacity as well as different feldspar compositions and crystallographic orientation. Ambient pressure experiments were run at RPI to diffuse Li from a powdered spodumene source into polished sanidine, albite, oligoclase or anorthite crystals over the temperature range 500-950 ºC. The resulting 7Li concentration gradients developed in the mineral specimens were evaluated using laser ablation ICP-MS. The new data show that Li diffusion in all feldspar compositions simultaneously operates by both a "fast" and "slow" diffusion mechanism. Fast path diffusivities are similar to those found by Giletti and Shanahan [1997] for Li diffusion in plagioclase and are typically 10 to 20 times greater than slow path diffusivities. Lithium concentration gradients in the feldspar experiments plot in the shape of two superimposed error function curves with the slow diffusion regime in the near-surface of the crystal. Lithium diffusion is most sluggish in sanidine and is significantly faster in the plagioclase feldspars. It is still unclear what diffusion mechanism operates in nature, but the new measurements may impact

Prospective conceptual qualification of hybrid centrifugation/distillatory for {sup 6}LI nuclear fusion technology scaled supply demands; Calificacion conceptual prospectiva de centrifugador/destilador hibrido para produccion de {sup 6}Li a demanda de la tecnologia Nuclear Fusion

Energy Technology Data Exchange (ETDEWEB)

Sedano, L.; Herranz, J. L.; Casado, J. L.; Castro, P.; Xiberta, J.

2013-07-01

The change in the demand for exploitation of lithium as a resource appears during the last decade, related to the development of the ion-Li batteries market and with the requirements of Nuclear Fusion fuels (deuterium and lithium) as coming energy option. A prospective analysis of synergistic demands of both markets, in its technical and in its economic aspects appears of prospective interest. The civil market {sup 6}Li/{sup 7}Li enrichment demand is analyzed. Specific technological developments permitting on-line production according to demand is discussed. A [centrifugation /thermal diffusion / combined distillation] technique is selected and qualified as technologically viable option for scaled production of litiated-forms. A conceptual design of a production plant is finally proposed according to the new technical capability.

Dynamic polarizabilities and Van der Waals coefficients for alkali atoms Li, Na and alkali dimer molecules Li2, Na2 and NaLi

Science.gov (United States)

Mérawa, M.; Dargelos, A.

1998-07-01

The present paper gives an account of investigations of the polarizability of the alkali atoms Li, Na, diatomics homonuclear and heteronuclear Li2, Na2 and NaLi at SCF (Self Consistent Field) level of approximation and at correlated level, using a time Time-Dependent Gauge Invariant method (TDGI). Our static polarizability values agree with the best experimental and theoretical determinations. The Van der Waals C6 coefficients for the atom-atom, atom-dimer and dimer-dimer interactions have been evaluated. Les polarisabilités des atomes alcalins Li, Na, et des molécules diatomiques homonucléaires et hétéronucléaire Li2, Na2 et NaLi, ont été calculées au niveau SCF (Self Consistent Field) et au niveau corrélé à partir d'une méthode invariante de jauge dépendante du temps(TDGI). Nos valeurs des polarisabilités statiques sont en accord avec les meilleurs déterminations expérimentales et théoriques. Les coefficients C6 de Van de Waals pour les interactions atome-atome, atome-dimère et dimère-dimère ont également été évalués.

Kinetic Monte Carlo Study of Li Intercalation in LiFePO4.

Science.gov (United States)

Xiao, Penghao; Henkelman, Graeme

2018-01-23

Even as a commercial cathode material, LiFePO 4 remains of tremendous research interest for understanding Li intercalation dynamics. The partially lithiated material spontaneously separates into Li-poor and Li-rich phases at equilibrium. Phase segregation is a surprising property of LiFePO 4 given its high measured rate capability. Previous theoretical studies, aiming to describe Li intercalation in LiFePO 4 , include both atomic-scale density functional theory (DFT) calculations of static Li distributions and entire-particle-scale phase field models, based upon empirical parameters, studying the dynamics of the phase separation. Little effort has been made to bridge the gap between these two scales. In this work, DFT calculations are used to fit a cluster expansion for the basis of kinetic Monte Carlo calculations, which enables long time scale simulations with accurate atomic interactions. This atomistic model shows how the phases evolve in Li x FePO 4 without parameters from experiments. Our simulations reveal that an ordered Li 0.5 FePO4 phase with alternating Li-rich and Li-poor planes along the ac direction forms between the LiFePO 4 and FePO 4 phases, which is consistent with recent X-ray diffraction experiments showing peaks associated with an intermediate-Li phase. The calculations also help to explain a recent puzzling experiment showing that LiFePO 4 particles with high aspect ratios that are narrower along the [100] direction, perpendicular to the [010] Li diffusion channels, actually have better rate capabilities. Our calculations show that lateral surfaces parallel to the Li diffusion channels, as well as other preexisting sites that bind Li weakly, are important for phase nucleation and rapid cycling performance.

Li4SiO4-Based Artificial Passivation Thin Film for Improving Interfacial Stability of Li Metal Anodes.

Science.gov (United States)

Kim, Ji Young; Kim, A-Young; Liu, Guicheng; Woo, Jae-Young; Kim, Hansung; Lee, Joong Kee

2018-03-14

An amorphous SiO 2 (a-SiO 2 ) thin film was developed as an artificial passivation layer to stabilize Li metal anodes during electrochemical reactions. The thin film was prepared using an electron cyclotron resonance-chemical vapor deposition apparatus. The obtained passivation layer has a hierarchical structure, which is composed of lithium silicide, lithiated silicon oxide, and a-SiO 2 . The thickness of the a-SiO 2 passivation layer could be varied by changing the processing time, whereas that of the lithium silicide and lithiated silicon oxide layers was almost constant. During cycling, the surface of the a-SiO 2 passivation layer is converted into lithium silicate (Li 4 SiO 4 ), and the portion of Li 4 SiO 4 depends on the thickness of a-SiO 2 . A minimum overpotential of 21.7 mV was observed at the Li metal electrode at a current density of 3 mA cm -2 with flat voltage profiles, when an a-SiO 2 passivation layer of 92.5 nm was used. The Li metal with this optimized thin passivation layer also showed the lowest charge-transfer resistance (3.948 Ω cm) and the highest Li ion diffusivity (7.06 × 10 -14 cm 2 s -1 ) after cycling in a Li-S battery. The existence of the Li 4 SiO 4 artificial passivation layer prevents the corrosion of Li metal by suppressing Li dendritic growth and improving the ionic conductivity, which contribute to the low charge-transfer resistance and high Li ion diffusivity of the electrode.

Eu and Rb co-doped LiCaAlF6 scintillators for neutron detection

International Nuclear Information System (INIS)

Yamaji, Akihiro; Yanagida, Takayuki; Kawaguchi, Noriaki; Yokota, Yuui; Fujimoto, Yutaka; Kurosawa, Shunsuke; Pejchal, Jan; Watanabe, Kenichi; Yamazaki, Atsushi; Yoshikawa, Akira

2013-01-01

Eu and Rb co-doped LiCaAlF 6 (LiCAF) single crystals with different dopant concentrations were grown by the micro-pulling-down method for neutron detection. Their transmittance spectra showed strong absorption bands at 200–220 and 290–350 nm, and under 241 Am alpha-ray excitation, their radioluminescence spectra exhibited an intense emission peak at 373 nm that was attributed to the Eu 2+ 5d–4f transition. These results were consistent with those for the Rb-free Eu:LiCAF. The highest light yield among the grown crystals was 36,000 ph/n, which was 20% greater than that of the Rb-free crystal. In addition, the neutron-excited scintillation decay times were 650–750 ns slower than that of the Rb-free Eu:LiCAF. -- Highlights: •Eu and Rb co-doped LiCaAlF 6 crystals were grown by the micro-pulling down method. •Transmittance, photoluminescence and radioluminescence spectra were measured. •The light yields and scintillation decays were evaluated under 252 Cf neutron irradiation

Water vapor concentration dependence and temperature dependence of Li mass loss from Li{sub 2}TiO{sub 3} with excess Li and Li{sub 4}SiO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Shimozori, Motoki [Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan); Katayama, Kazunari, E-mail: kadzu@nucl.kyushu-u.ac.jp [Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan); Hoshino, Tsuyoshi [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuch, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Ushida, Hiroki; Yamamoto, Ryotaro; Fukada, Satoshi [Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan)

2015-10-15

Highlights: • Li mass loss from Li{sub 2.11}TiO{sub 3} increased proportionally to water vapor pressure. • Li mass loss from Li{sub 2.11}TiO{sub 3} at 600 °C was significantly smaller than expected. • Differences of Li mass loss behavior from Li{sub 2.11}TiO{sub 3} and Li{sub 4}SiO{sub 4} were shown. - Abstract: In this study, weight reduction of Li{sub 2}TiO{sub 3} with excess Li and Li{sub 4}SiO{sub 4} at elevated temperatures under hydrogen atmosphere or water vapor atmosphere was investigated. The Li mass loss for the Li{sub 2}TiO{sub 3} at 900 °C was 0.4 wt% under 1000 Pa H{sub 2} atmosphere and 1.5 wt% under 50 Pa H{sub 2}O atmosphere. The Li mass loss for the Li{sub 2}TiO{sub 3} increased proportionally to the water vapor pressure in the range from 50 to 200 Pa at 900 °C and increased with increasing temperature from 700 to 900 °C although Li mass loss at 600 °C was significantly smaller than expected. It was found that water vapor concentration dependence and temperature dependence of Li mass loss for the Li{sub 2}TiO{sub 3} and the Li{sub 4}SiO{sub 4} used in this work were quite different. Water vapor is released from the ceramic breeder materials into the purge gas due to desorption of adsorbed water and water formation reaction. The released water vapor possibly promotes Li mass loss with the formation of LiOH on the surface.

Li2 NH-LiBH4 : a Complex Hydride with Near Ambient Hydrogen Adsorption and Fast Lithium Ion Conduction.

Science.gov (United States)

Wang, Han; Cao, Hujun; Zhang, Weijin; Chen, Jian; Wu, Hui; Pistidda, Claudio; Ju, Xiaohua; Zhou, Wei; Wu, Guotao; Etter, Martin; Klassen, Thomas; Dornheim, Martin; Chen, Ping

2018-01-26

Complex hydrides have played important roles in energy storage area. Here a complex hydride made of Li 2 NH and LiBH 4 was synthesized, which has a structure tentatively indexed using an orthorhombic cell with a space group of Pna2 1 and lattice parameters of a=10.121, b=6.997, and c=11.457 Å. The Li 2 NH-LiBH 4 sample (in a molar ratio of 1:1) shows excellent hydrogenation kinetics, starting to absorb H 2 at 310 K, which is more than 100 K lower than that of pristine Li 2 NH. Furthermore, the Li + ion conductivity of the Li 2 NH-LiBH 4 sample is about 1.0×10 -5  S cm -1 at room temperature, and is higher than that of either Li 2 NH or LiBH 4 at 373 K. Those unique properties of the Li 2 NH-LiBH 4 complex render it a promising candidate for hydrogen storage and Li ion conduction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Much improved capacity and cycling performance of LiVMoO6 cathode for lithium ion batteries

International Nuclear Information System (INIS)

Zhou Liqun; Liang Yongguang; Hu Ling; Han Xiaoyan; Yi Zonghui; Sun Jutang; Yang Shuijin

2008-01-01

Spherical LiVMoO 6 nanocrystals as cathode for lithium ion batteries were synthesized using a solvothermal reaction method. Powder XRD data indicate that a single phase LiVMoO 6 with brannerite-type structure is obtained at 550 deg. C by the thermal treatment of the precursor for 6 h. SEM image shows that the particles are composed of loosely stacked spheres with a uniform particle size about 40 nm. The electrode properties of LiVMoO 6 have also been studied by galvanostatic cycling and ac impedance spectroscopy. LiVMoO 6 nanospheres delivered 172 mAh g -1 capacity in the initial discharge process with a reversible capacity retention of 94.4% after 100 cycles in the range of 3.6-1.80 V versus metallic Li at a current density of 100 mA g -1 . The microstructure developed in the electrodes give evidence that the particle size and morphological properties play an important role in the much improved capacity and cycling stability at large currents than ordinary samples

Recovery of Li from alloys of Al- Li and Li- Al using engineered scavenger compounds

Science.gov (United States)

Riley, W. D.; Jong, B. W.; Collins, W. K.; Gerdemann, S. J.

1994-01-01

A method of producing lithium of high purity from lithium aluminum alloys using an engineered scavenger compound, comprising: I) preparing an engineered scavenger compound by: a) mixing and heating compounds of TiO2 and Li2CO3 at a temperature sufficient to dry the compounds and convert Li.sub.2 CO.sub.3 to Li.sub.2 O; and b) mixing and heating the compounds at a temperature sufficient to produce a scavenger Li.sub.2 O.3TiO.sub.2 compound; II) loading the scavenger into one of two electrode baskets in a three electrode cell reactor and placing an Al-Li alloy in a second electrode basket of the three electrode cell reactor; III) heating the cell to a temperature sufficient to enable a mixture of KCl-LiCl contained in a crucible in the cell to reach its melting point and become a molten bath; IV) immersing the baskets in the bath until an electrical connection is made between the baskets to charge the scavenger compound with Li until there is an initial current and voltage followed by a fall off ending current and voltage; and V) making a connection between the basket electrode containing engineered scavenger compound and a steel rod electrode disposed between the basket electrodes and applying a current to cause Li to leave the scavenger compound and become electrodeposited on the steel rod electrode.

Electrochemical Properties of the LiNi0.6Co0.2Mn0.2O2 Cathode Material Modified by Lithium Tungstate under High Voltage.

Science.gov (United States)

Fu, Jiale; Mu, Daobin; Wu, Borong; Bi, Jiaying; Cui, Hui; Yang, Hao; Wu, Hanfeng; Wu, Feng

2018-05-31

An amount (5 wt %) of lithium tungstate (Li 2 WO 4 ) as an additive significantly improves the cycle and rate performances of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode at the cutoff voltage of 4.6 V. The 5 wt % Li 2 WO 4 -mixed LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode delivers a reversible capacity of 199.2 mA h g -1 and keeps 73.1% capacity for 200 cycles at 1 C. It retains 67.4% capacity after 200 cycles at 2 C and delivers a discharge capacity of 167.3 mA h g -1 at 10 C, while those of the pristine electrode are only 44.7% and 87.5 mA h g -1 , respectively. It is shown that the structure of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode material is not affected by mixing Li 2 WO 4 . The introduced Li 2 WO 4 effectively restrains the LiPF 6 and carbonate solvent decomposition by consuming PF 5 at high cutoff voltage, forming a stable cathode/electrolyte interface film with low resistance.

Formation and control of zinc nitride in a molten LiCl-KCl-Li3N system

International Nuclear Information System (INIS)

Goto, Takuya; Toyoura, Kazuaki; Tsujimura, Hiroyuki; Ito, Yasuhiko

2004-01-01

We investigated a possibility of electrochemical formation and control of zinc nitride in a molten LiCl-KCl-Li 3 N system at 673 K. Zinc nitride films were obtained by means of potentiostatic electrolysis of zinc electrodes in the melt. From XRD analysis, it was confirmed that obtained films consisted of Zn 3 N 2 and LiZnN and that the composition of each film was effected by the applied potential value. In the potential range from 0.75 to 1.6 V (versus Li + /Li), the ratio of Zn 3 N 2 increased as the applied potential was more positive. Based on the result, we achieved the formation of Zn 3 N 2 film (3-5 μm) in anti-scandium oxide structure (a = 0.977 nm) by means of potentiostatic electrolysis at 1.6 V for 3 h

Nuclear reactions of the system 6 Li on 58 Ni near the Coulomb barrier

International Nuclear Information System (INIS)

Lizcano, D.; Aguilera, E.F.; Garcia M, H.; Martinez Q, E.

2004-01-01

Protons, alpha particles and deuterons coming from the reactions 6 Li + 58 Ni are detected to three different energy around the Coulomb barrier. The possible effects of the weakly bound character of the projectile are studied and the results are compared with previous data for the system 6 Li + 59 Co. (Author)

EPR experiments in LiTbF4, LiHoF4, and LiErF4 at submillimeter frequencies

DEFF Research Database (Denmark)

Magariño, J.; Tuchendler, J.; Beauvillain, P.

1980-01-01

Electron-paramagnetic-resonance experiments in LiTbF4, LiHoF4, and LiErF4 have been performed at frequencies between 70 and 600 GHz, in magnetic fields up to 60 kG and in the temperature range 1.4......Electron-paramagnetic-resonance experiments in LiTbF4, LiHoF4, and LiErF4 have been performed at frequencies between 70 and 600 GHz, in magnetic fields up to 60 kG and in the temperature range 1.4...

Absorption of water vapour in the falling film of water-(LiBr + LiI + LiNO{sub 3} + LiCl) in a vertical tube at air-cooling thermal conditions

Energy Technology Data Exchange (ETDEWEB)

Bourouis, Mahmoud; Valles, Manel; Medrano, Marc; Coronas, Alberto [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, CREVER, Universitat Rovira i Virgili, Autovia de Salou, s/n, 43006, Tarragona (Spain)

2005-05-01

In air-cooled water-LiBr absorption chillers the working conditions in the absorber and condenser are shifted to higher temperatures and concentrations, thereby increasing the risk of crystallisation. To develop this technology, two main problems are to be addressed: the availability of new salt mixtures with wider range of solubility than water-LiBr, and advanced absorber configurations that enable to carry out simultaneously an appropriate absorption process and an effective air-cooling. One way of improving the solubility of LiBr aqueous solutions is to add other salts to create multicomponent salt solutions. The aqueous solution of the quaternary salt system (LiBr + LiI + LiNO{sub 3} + LiCl) presents favourable properties required for air-cooled absorption systems: less corrosive and crystallisation temperature about 35 K lower than that of water-LiBr.This paper presents an experimental study on the absorption of water vapour over a wavy laminar falling film of an aqueous solution of (LiBr + LiI + LiNO{sub 3} + LiCl) on the inner wall of a water-cooled smooth vertical tube. Cooling water temperatures in the range 30-45 C were selected to simulate air-cooling thermal conditions. The results are compared with those obtained in the same experimental set-up with water-LiBr solutions.The control variables for the experimental study were: absorber pressure, solution Reynolds number, solution concentration and cooling water temperature. The parameters considered to assess the absorber performance were: absorber thermal load, mass absorption flux, degree of subcooling of the solution leaving the absorber, and the falling film heat transfer coefficient.The higher solubility of the multicomponent salt solution makes possible the operation of the absorber at higher salt concentration than with the conventional working fluid water-LiBr. The absorption fluxes achieved with water-(LiBr + LiI + LiNO{sub 3} + LiCl) at a concentration of 64.2 wt% are around 60 % higher than

LiCaAlF sub 6 :Ce crystal: a new scintillator

CERN Document Server

Gektin, A V; Neicheva, S; Gavrilyuk, V; Bensalah, A; Fukuda, T; Shimamura, K

2002-01-01

Scintillation properties of LiCaAlF sub 6 :Ce crystal, well known as the effective UV laser material, is reported. Ce sup 3 sup + emission at 286-305 nm with a single exponential decay time of 35 ns provides a scintillation pulse. Radiation damage in pure and Ce-doped crystals is studied. In contrast to the majority of fluoride crystals, cerium is responsible for the ultradeep traps formation revealing thermostimulated luminescence. Overlapping of color center absorption and Ce sup 3 sup + ion emission bands limits the scintillation efficiency of LiCaAlF sub 6 :Ce at high radiation doses.

Hydrogen storage properties of rare earth (RE) borohydrides (RE = La, Er) in composite mixtures with LiBH{sub 4} and LiH

Energy Technology Data Exchange (ETDEWEB)

Frommen, Christoph; Heere, Michael [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Riktor, Marit D. [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); SINTEF Materials and Chemistry, Forskningsveien 1, NO-0314 Oslo (Norway); Sørby, Magnus H. [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Hauback, Bjørn C., E-mail: bjorn.hauback@ife.no [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway)

2015-10-05

Highlights: • 6LiBH{sub 4}–RECl{sub 3}–3LiH composites (RE = La, Er) studied for the first time. • Drastically reduced decomposition temperature (300 {sup o}C) compared to LiBH{sub 4} (>400 °C). • Partial reversibility for 6LiBH{sub 4}–LaCl{sub 3}–3LiH: (19% at 340 °C, 10 MPa). • Excellent reversibility for 6LiBH{sub 4}–ErCl{sub 3}–3LiH: (80% at 340 °C, 10 MPa). • Reversibility comparable to that obtained for pure LiBH{sub 4} (76% at 600 °C and 15.5 MPa). - Abstract: Mixtures of 6LiBH{sub 4}–RECl{sub 3}–3LiH (RE = La, Er) have been produced by mechanochemical milling and their structure, thermal decomposition and reversibility have been studied. Hydrogen desorption starts around 300 °C in both composites. Heating to 400 °C yields LaB{sub 6}, ErB{sub 4} and REH{sub 2+δ} as major decomposition products. LiBH{sub 4} is destabilized by REH{sub 2+δ} formed through decomposition of the parent borohydrides LiLa(BH{sub 4}){sub 3}Cl and Er(BH{sub 4}){sub 3}, respectively, and its hydrogen release temperature is reduced by 100 °C as compared to pure ball-milled LiBH{sub 4}. The lanthanum-containing composite releases 4.2 wt.% H between 300 and 350 °C and shows a limited reversibility of ∼20% (340 °C, 10 MPa) probably due to hydrogen uptake by some amorphous boron-containing phases. For 6LiBH{sub 4}–ErCl{sub 3}–3LiH about 3 wt.% H is evolved up to 400 °C. Desorption against 0.5 MPa backpressure results in an increased reversibility (∼80%) as compared to vacuum (∼66%). Rehydrogenation (340 °C, 10 MPa) shows the formation of ErH{sub 3} and LiBH{sub 4} at drastically reduced conditions compared to pure LiBH{sub 4} (>400 °C, >10 MPa)

Large-Area Neutron Detector based on Li-6 Pulse Mode Ionization Chamber

International Nuclear Information System (INIS)

Chung, K.; Ianakiev, K.D.; Swinhoe, M.T.; Makela, M.F.

2005-01-01

Prototypes of a Li-6 Pulse Mode Ionization Chamber (LiPMIC) have been in development for the past two years for the purpose of providing large-area neutron detector. this system would be suitable for remote deployment for homeland security and counterterrorism needs at borders, ports, and nuclear facilities. A prototype of LiPMIC is expected to provide a similar level of performance to the current industry-standard, He-3 proportional counters, while keeping the initial cost of procurement down by an order of magnitude, especially where large numbers of detectors are required. The overall design aspect and the efficiency optimization process is discussed. Specifically, the MCNP simulations of a single-cell prototype were performed and benchmarked with the experimental results. MCNP simulations of a three dimensional array design show intrinsic efficiency comparable to that of an array of He-3 proportional counters. LiPMIC has shown steady progress toward fulfilling the design expectations and future design modification and optimization are discussed.

Low energy 7Li(p,n)7Be neutron source (CANUTRON)

International Nuclear Information System (INIS)

Lone, M.A.; Ross, A.M.; Fraser, J.S.; Schriber, S.O.; Kushneriuk, S.A.; Selander, W.N.

1982-04-01

Characteristics of a neutron source based on the 7 Li(p,n) reaction at 2.5 MeV are investigated. It is shosn that with a 10-50 mA beam current this reaction provides a useful source for neutron radiography and other industrial applications

Study of the nuclear continuum of 28Si after excitation by inelastic 6Li scattering

International Nuclear Information System (INIS)

Seegert, G.

1985-01-01

For the study of the direct reaction mechanisms which contribute in the inelastic 6 Li scattering to the nuclear continuum of 28 Si at the Karlsruhe Isochronous Cyclotron particle-particle coincidence experiments were performed at an incident 6 Li energy of 156 MeV. Thereby the inelastically scattered 6 Li ions were measured in Si semiconductor telescopes under an angle of THETA=11 0 respectively 10 0 , while the coincident charged particles, mainly α particles with an energy of 70 MeV and protons with an energy up to 50 MeV could be detected in an angular range of -85 0 0 and three angles beyond the reaction plane. For a limited angular range simultaneously the α and 3 He fragments produced by the breakup of the 6 Li particle were taken up in coincidence with all light charged particles. (orig./HSI) [de

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

Directory of Open Access Journals (Sweden)

Luong D.H.

2013-12-01

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

Ultralong Lifespan and Ultrafast Li Storage: Single-Crystal LiFePO4 Nanomeshes.

Science.gov (United States)

Zhang, Yan; Zhang, Hui Juan; Feng, Yang Yang; Fang, Ling; Wang, Yu

2016-01-27

A novel LiFePO4 material, in the shape of a nanomesh, has been rationally designed and synthesized based on the low crystal-mismatch strategy. The LiFePO4 nanomesh possesses several advantages in morphology and crystal structure, including a mesoporous structure, its crystal orientation that is along the [010] direction, and a shortened Li-ion diffusion path. These properties are favorable for their application as cathode in Li-ion batteries, as these will accelerate the Li-ion diffusion rate, improve the Li-ion exchange between the LiFePO4 nanomesh and the electrolyte, and reduce the Li-ion capacitive behavior during Li intercalation. So the LiFePO4 nanomesh exhibits a high specific capacity, enhanced rate capability, and strengthened cyclability. The method developed here can also be extended to other similar systems, for instance, LiMnPO4 , LiCoPO4 , and LiNiPO4 , and may find more applications in the designed synthesis of functional materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous measurement of angular distribution of elastic scattering for 6Li, 7Be, and 8B in 58Ni

International Nuclear Information System (INIS)

Ruiz S, A.; Martinez Q, E.; Aguilera R, E.F.; Murillo O, G.; Lizcano C, D.; Gomez C, A.

2007-01-01

The experimental angular distributions of elastic scattering for the projectiles 6 Li, 7 Be, 8 B in 58 Ni were obtained. Using the Optical model with a Woods-Saxon potential form, as much for the real part as for the imaginary one, an adjustment to the experimental data varying only the depth of the imaginary part of the potential is made. A comparison of the results obtained for each projectile is made. (Author)

Synthesis and structure of Li{sub 4}GeS{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Matsushita, Y [National Inst. of Materials and Chemical Research, Tsukuba (Japan). High Pressure Lab.; Kanatzidis, M G [Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry

1998-01-01

The compound Li{sub 4}GeS{sub 4} has been prepared as transparent, light yellow moisture-sensitive crystals. Li{sub 4}GeS{sub 4} belongs to the space group Pnma with a = 14.107(6) A, b = 7.770(3) A and c = 6.162(2) A. The crystal structure was solved by direct-methods. The final R and R{sub w}-values are 1.85 and 1.65% for 866 observed reflections. The Li{sub 4}GeS{sub 4} structure has three crystallographically independent lithium sites and one germanium site. The lithium atoms adopt two different coordination types. The Li1 atom is coordinated to five sulfur atoms in a square pyramidal geometry, while the Li2 and Li3 atoms have distorted tetrahedral coordination. The Ge atom is tetrahedrally coordinated by four sulfur atoms and is found as [GeS{sub 4}]{sup 4-} units. The anisotropic three-dimensional crystal structure of Li{sub 4}GeS{sub 4} is described. (orig.) 57 refs.

Continuous flame aerosol synthesis of carbon-coated nano-LiFePO4 for Li-ion batteries

Science.gov (United States)

Waser, Oliver; Büchel, Robert; Hintennach, Andreas; Novák, Petr; Pratsinis, Sotiris E.

2013-01-01

Core-shell, nanosized LiFePO4-carbon particles were made in one step by scalable flame aerosol technology at 7 g/h. Core LiFePO4 particles were made in an enclosed flame spray pyrolysis (FSP) unit and were coated in-situ downstream by auto thermal carbonization (pyrolysis) of swirl-fed C2H2 in an O2-controlled atmosphere. The formation of acetylene carbon black (ACB) shell was investigated as a function of the process fuel-oxidant equivalence ratio (EQR). The core-shell morphology was obtained at slightly fuel-rich conditions (1.0 < EQR < 1.07) whereas segregated ACB and LiFePO4 particles were formed at fuel-lean conditions (0.8 < EQR < 1). Post-annealing of core-shell particles in reducing environment (5 vol% H2 in argon) at 700 °C for up to 4 hours established phase pure, monocrystalline LiFePO4 with a crystal size of 65 nm and 30 wt% ACB content. Uncoated LiFePO4 or segregated LiFePO4-ACB grew to 250 nm at these conditions. Annealing at 800 °C induced carbothermal reduction of LiFePO4 to Fe2P by ACB shell consumption that resulted in cavities between carbon shell and core LiFePO4 and even slight LiFePO4 crystal growth but better electrochemical performance. The present carbon-coated LiFePO4 showed superior cycle stability and higher rate capability than the benchmark, commercially available LiFePO4. PMID:23407817

Ion exchange and electrochemical evaluation of the microporous phosphate Li9Fe7(PO4)10

International Nuclear Information System (INIS)

Becht, Gregory A.; Vaughey, John T.; Britt, Robin L.; Eagle, Cassandra T.; Hwu, Shiou-Jyh

2008-01-01

A new lithium iron(III) phosphate, Li 9 Fe 7 (PO 4 ) 10 , has been synthesized and is currently under electrochemical evaluation as an anode material for rechargeable lithium-ion battery applications. The sample was prepared via the ion exchange reaction of Cs 5 K 4 Fe 7 (PO 4 ) 10 1 in the 1 M LiNO 3 solution under hydrothermal conditions at 200 deg. C. The fully Li + -exchanged sample Li 9 Fe 7 (PO 4 ) 10 2 cannot yet be synthesized by conventional high-temperature, solid-state methods. The parent compound 1 is a member of the Cs 9-x K x Fe 7 (PO 4 ) 10 series that was previously isolated from a high-temperature (750 deg. C) reaction employing the eutectic CsCl/KCl molten salt. The polycrystalline solid 1 was first prepared in a stoichiometric reaction via conventional solid-state method then followed by ion exchange giving rise to 2. Both compounds adopt three-dimensional structures that consist of orthogonally interconnected channels where electropositive ions reside. It has been demonstrated that the Cs 9-x K x Fe 7 (PO 4 ) 10 series possesses versatile ion exchange capabilities with all the monovalent alkali metal and silver cations due to its facile pathways for ion transport. 1 and 2 were subject to electrochemical analysis and preliminary results suggest that the latter can be considered as an anode material. Electrochemical results indicate that Li 9 Fe 7 (PO 4 ) 10 is reduced below 1 V (vs. Li) to most likely form a Fe(0)/Li 3 PO 4 composite material, which can subsequently be cycled reversibly at relatively low potential. An initial capacity of 250 mAh/g was measured, which is equivalent to the insertion of thirteen Li atoms per Li 9+x Fe 7 (PO 4 ) 10 (x = 13) during the charge/discharge process (Fe 2+ + 2e → Fe 0 ). Furthermore, 2 shows a lower reduction potential (0.9 V), by approximately 200 mV, and much better electrochemical reversibility than iron(III) phosphate, FePO 4 , highlighting the value of improving the ionic conductivity of the sample

6Li real potential volume integrals in elastic scattering and distorted-waveBorn approximation analyses

International Nuclear Information System (INIS)

Lezoch, P.; Trost, H.; Strohbusch, U.

1981-01-01

The magnitudes of volume integrals per interacting nucleon pair J/sub R/' calculated from a compilation of 6 Li potentials vary between 100 and 500 MeV fm 3 . They are grouped in discrete branches with J/sub R/(A) smoothly increasing with decreasing target mass. Comparison with the results for lighter projectiles restricts the ''physically meaningful'' branches to those characterized by J/sub R/ (A> or =48) 3 . ( 6 Li,d) reaction analyses yield the same fit qualities for 6 Li potentials of the different discrete families, but deduced spectroscopic factors jump (by factors of approx.3) when changing between successive families

Coulomb sums for 7Li nucleus at 3-momentum transfers q=1,250...1,625 fm-1

International Nuclear Information System (INIS)

Buki, A.Yu.; Shevchenko, N.G.; Timchenko, I.S.

2009-01-01

The experimental response functions of 7 Li nucleus at effective 3-momentum transfers q = 1.250; 1.375; 1.500 and 1.625 fm -1 are presented. The longitudinal response functions were used to evaluate the Coulomb sum values. The Coulomb sums for 6 Li obtained by us earlier were applied to analyze these data. The Coulomb sums of lithium isotopes were compared with the well-known Coulomb sums values of the other nuclei

Experimental research of plastic scintillation detector loaded 6Li neutron energy response

International Nuclear Information System (INIS)

Wang Lizong; Zhang Chuanfei; Peng Taiping; Guo Cun; Yang Hongqiong; Zhang Jianhua

2005-01-01

A new plastic scintillator, plastic scintillator loaded 6 Li, is brought forward and developed in this paper in order to increase low energy neutron sensitivity. Neutron sensitivity of several plastic scintillation detectors loaded 6 Li new developed in neutron energy range 0.2 MeV-5.0 MeV are calibrated by direct current at serial accelerator. Energy response curves of the detectors are obtained in this experiment. It is shown that this new plastic scintillation detector can increase low energy neutron sensitivity in experimental results. (authors)

Re-entrant lithium local environments and defect driven electrochemistry of Li- and Mn-rich Li-ion battery cathodes.

Science.gov (United States)

Dogan, Fulya; Long, Brandon R; Croy, Jason R; Gallagher, Kevin G; Iddir, Hakim; Russell, John T; Balasubramanian, Mahalingam; Key, Baris

2015-02-18

Direct observations of structure-electrochemical activity relationships continue to be a key challenge in secondary battery research. (6)Li magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is the only structural probe currently available that can quantitatively characterize local lithium environments on the subnanometer scale that dominates the free energy for site occupation in lithium-ion (Li-ion) intercalation materials. In the present study, we use this local probe to gain new insights into the complex electrochemical behavior of activated 0.5(6)Li2MnO3·0.5(6)LiMn(0.5)Ni(0.5)O2, lithium- and manganese-rich transition-metal (TM) oxide intercalation electrodes. We show direct evidence of path-dependent lithium site occupation, correlated to structural reorganization of the metal oxide and the electrochemical hysteresis, during lithium insertion and extraction. We report new (6)Li resonances centered at ∼1600 ppm that are assigned to LiMn6-TM(tet) sites, specifically, a hyperfine shift related to a small fraction of re-entrant tetrahedral TMs (Mn(tet)), located above or below lithium layers, coordinated to LiMn6 units. The intensity of the TM layer lithium sites correlated with tetrahedral TMs loses intensity after cycling, indicating limited reversibility of TM migrations upon cycling. These findings reveal that defect sites, even in dilute concentrations, can have a profound effect on the overall electrochemical behavior.

Revisiting the 7Li(p,n)7Be reaction near threshold

International Nuclear Information System (INIS)

Herrera, María S.; Moreno, Gustavo A.; Kreiner, Andrés J.

2014-01-01

In this work we review all the available experimental neutron data for the 7 Li(p,n) reaction near threshold which is necessary to obtain an accurate source model for Monte Carlo simulations in Boron Neutron Capture Therapy. Scattered published experimental results such as cross sections, differential neutron yields and total yields were collected and analyzed, exploring the sensitivity of the fitting parameters to the different possible variables and deriving a consistent working set of parameters to evaluate the neutron source near threshold. - Highlights: • We review neutron experimental data for the 7 Li(p,n) reaction near threshold. • A new computational method was used to study all the available published data. • A consistent description of the neutron source was derived fitting the available data. • We found that the neutron yield at 0° studied by Kononov is the most sensitive curve. • A consistent set of parameters to parametrize the Breit–Wigner formula is presented

Production of 232,233Pa in 6Li+232Th Collisions in the Classical Trajectory Approach

International Nuclear Information System (INIS)

Aleshin, V.P.

2000-01-01

The semiclassical model of nuclear reactions with loosely bound projectiles (V.P. Aleshin, B.I. Sidorenko, Acta Phys. Pol. B29, 325 (1998)) is refined and compared with experimental data of Rama Rao et al. on the excitation function for the production of 232,233 Pa in 6 Li+ 232 Th collisions at E = 30-50 MeV. The main contribution to the production of 232 Pa is the 2 neutron emission from excited states of 234 Pa formed in the ( 6 Li,α) reaction. The main source of 233 Pa is the ( 6 Li,αp) reaction followed by γ transitions from excited states of 233 Th to 233 Th (g.s.) which transforms to 233 Pa through β - decay. The ground state of 6 Li regarded as a combination of n+p+α is modeled with the K=2, l x =l y =0 hyperspherical function. The calculation underpredicts the excitation function of 232 Pa by a factor of 0.6 and overpredicts the excitation function of 233 Pa by a factor of 2.3, on the average. With the more realistic wave function of 6 Li both factors are expected to be closer to 1. (author)

Study of the structural and thermal stability of Li0.3Co2/3Ni1/6Mn1/6O2

International Nuclear Information System (INIS)

Mahmoud, Abdelfattah; Saadoune, Ismael; Difi, Siham; Sougrati, Moulay Tahar; Lippens, Pierre-Emmanuel; Amarilla, José Manuel

2014-01-01

Thermal and structural stabilities of the delithiated positive electrode material Li x Co 2/3 Ni 1/6 Mn 1/6 O 2 were studied by X-ray diffraction, magnetic and thermogravimetric analysis. In the opposite to the classical electrode materials LiNiO 2 and LiCoO 2 , the structural symmetry (S.G. R-3 m) of the starting material LiCo 2/3 Ni 1/6 Mn 1/6 O 2 is preserved during the electrochemical cycling with a small variation of the unit cell parameters. Squid measurements evidenced that practically no Ni 2+ ions were present in the lithium slab even after the lithium extraction process. For the thermal stability, the highly oxidized phase Li 0.3 Co 2/3 Ni 1/6 Mn 1/6 O 2 was tested. This delithiated phase undergoes only 5.16% weight loss after heating up to 600 °C. This weight loss has no effect on the structure symmetry as the starting α-NaFeO 2 type structure was preserved during the thermal treatment. The obtained results coupled to the excellent electrochemical features of LiCo 2/3 Ni 1/6 Mn 1/6 O 2 clearly showits ability to compete with the commercialized cathode materials

Deciphering the Precision of Stereo IKONOS Canopy Height Models for US Forests with G-LiHT Airborne LiDAR

Directory of Open Access Journals (Sweden)

Christopher S. R. Neigh

2014-02-01

Full Text Available Few studies have evaluated the precision of IKONOS stereo data for measuring forest canopy height. The high cost of airborne light detection and ranging (LiDAR data collection for large area studies and the present lack of a spaceborne instrument lead to the need to explore other low cost options. The US Government currently has access to a large archive of commercial high-resolution imagery, which could be quite valuable to forest structure studies. At 1 m resolution, we here compared canopy height models (CHMs and height data derived from Goddard’s airborne LiDAR Hyper-spectral and Thermal Imager (G-LiHT with three types of IKONOS stereo derived digital surface models (DSMs that estimate CHMs by subtracting National Elevation Data (NED digital terrain models (DTMs. We found the following in three different forested regions of the US after excluding heterogeneous and disturbed forest samples: (1 G-LiHT DTMs were highly correlated with NED DTMs with R2 > 0.98 and root mean square errors (RMSEs < 2.96 m; (2 when using one visually identifiable ground control point (GCP from NED, G-LiHT DSMs and IKONOS DSMs had R2 > 0.84 and RMSEs of 2.7 to 4.1 m; and (3 one GCP CHMs for two study sites had R2 > 0.7 and RMSEs of 2.6 to 3 m where data were collected less than four years apart. Our results suggest that IKONOS stereo data are a useful LiDAR alternative where high-quality DTMs are available.

Study of the Threshold Anomaly in the Scattering of Li Isotopes on 27Al

International Nuclear Information System (INIS)

Fernandez Niello, J.O.; Figueira, J.M.; Abriola, D.; Arazi, A.; Capurro, O.A.; Marti, G.V.; Martinez Heinmann, D.; Pacheco, A.J.; Barbara, E. de; Padron, I.; Gomes, P.R.S.; Lubian, J.

2007-01-01

Angular distributions of 6,7 Li scattered by 27 Al have been measured at different bombarding energies between 6 and 18 MeV. The results obtained from an optical model analysis using several potentials indicate that there is an isotopic dependence in the energy variation of the real and imaginary strengths. Whereas the 7 Li + 27 Al system shows no indication of any threshold anomaly, the 6 Li + 27 Al reaction suggests the presence of the so-called breakup threshold anomaly

Search for a resonant enhancement of the 7Be + d reaction and primordial 7Li abundances

International Nuclear Information System (INIS)

O'Malley, Patrick; Adekola, A.S.; Cizewski, J.A.; Howard, M.E.; Strauss, S.; Bardayan, Daniel W.; Chae, Kyung Yuk; Nesaraja, Caroline D.; Pain, Steven D.; Smith, Michael Scott; Ahn, S.H.; Jones, K.L.; Pittman, S.T.; Schmitt, Kyle; Graves, S.; Kozub, R.L.; Shriner, J.F. Jr.; Wheeler, J.L.; Linhardt, Laura; Matos, M.; Moazen, B.M.; Peters, W.A.; Spassova, I.

2011-01-01

Big Bang nucleosynthesis calculations, constrained by the Wilkinson Microwave Anisotropy Probe results, produce 7 Li abundances almost a factor of four larger than those extrapolated from observations. Since primordial 7 Li is believed to be mostly produced by the beta decay of 7 Be, one proposed solution to this discrepancy is a resonant enhancement of the 7 Be(d,p)2α reaction rate through the 5/2 + 16.7-MeV state in 9 B. The 2 H( 7 Be,d) 7 Be reaction was used to search for such a resonance; none was observed. An upper limit on the width of the proposed resonance was deduced.

Thermoluminescence and radioluminescence properties of tissue equivalent Cu-doped Li2B4O7 for radiation dosimetry

International Nuclear Information System (INIS)

Cruz Z, E.; Furetta, C.; Marcazzo, J.; Santiago, M.; Guarneros, C.; Pacio, M.; Palomino, R.

2015-10-01

Thermoluminescence (Tl) and radioluminescence (Rl) properties of lithium tetraborate (Li 2 B 4 O 7 ) doped with different concentration of copper (0.25, 0.5, 1 wt %) under gamma and beta irradiation has been investigated. The feasibility of using this borate in radiation dosimetry at low doses has been evaluated. Tissue equivalent Li 2 B 4 O 7 was prepared by solid state reaction using mixing stoichiometric compositions of lithium carbonate (Li 2 CO 3 ) and boric acid (H 3 BO 3 ) and a solution of CuCl 2 as dopant. The glow curve, of the most efficient copper doped borate (Li 2 B 4 O 7 :Cu 0.5 wt %), shows a main stable peak centered at 225 degrees C and a second low temperature peak centered at 80 degrees C. The low temperature peak disappears completely after 24 hours of storage in darkness and at room temperature or after an annealing at 120 degrees C for 10 seconds. The main peak of the Li 2 B 4 O 7 :Cu remains constant. The Tl response of Li 2 B 4 O 7 :Cu shows good linearity in the analyzed dose range. The stability and repeatability of Rl signals of the borate have been studied and the Li 2 B 4 O 7 :Cu (0.5 wt %) shown the higher Rl emission and a stable and repetitive response. Results show that Li 2 B 4 O 7 :Cu has prospects to be used in gamma and beta radiation dosimetry. (Author)

Electrochemical properties and lithium ion diffusion in Li4FeSbO6 studied by first principle

Science.gov (United States)

Jia, Mingzhen; Wang, Hongyan; Wang, Hui; Chen, Yuanzheng; Guo, Chunsheng; Gan, Liyong

2017-10-01

Due to the high capacity, Li-rich materials Li2MO3 (M = transition metal) have attracted considerable attention as the next generation of Li-ion batteries. Li4FeSbO6 is a new Li-rich layered oxide material with antiferromagnet honeycomb structure. In this work, the electrochemical behavior, charging process and oxygen stability of LixFeSbO6 (0 ≤ xextracted, the charge compensation is mainly contributed by the oxygen atoms through analyzing the Bader charges of each element. In addition, oxygen evolution reactions will occur in LixFeSbO6 (x ≤ 1.5), which will decay the capacities during cycling process. Finally, we calculated that the lithium ion can diffuse in a three-dimensional pathway with the activation barriers from 0.36 eV to 0.67 eV.

Evaluation of Ce3+ and alkali metal ions Co-doped LiSrAlF6 crystalline scintillators

International Nuclear Information System (INIS)

Wakahara, Shingo; Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Pejchal, Jan; Kurosawa, Shunsuke; Suzuki, Shotaro; Kawaguchi, Noriaki; Fukuda, Kentaro; Yoshikawa, Akira

2013-01-01

High scintillation efficiency of Eu-doped LiSrAlF 6 (LiSAF) and LiCaAlF 6 (LiCAF) codoped with alkali metal ions has been reported in our recent studies. Thus in this paper, we demonstrated the scintillation properties of 1% Ce-doped LiSAF crystals with 1% alkali metal ions co-doping to increase the light yield and understand the scintillation mechanism. The crystals showed intense emission band corresponding to the 5d-4f transition of Ce 3+ , and their light yields under thermal neutron excitation were higher than that of the Ce only doped crystal. Especially, the light yield of Ce–Na co-doped crystal exceeded about two times that of Ce only doped one. -- Highlights: ► Ce-doped and alkali metal co-doped LiSAF crystals were grown by μ-PD method. ► Alkali metal co-doped crystals showed higher light yield than Ce only doped crystal. ► Decay time of alkali metal co-doped LiSAF were longer than that of Ce only doped one

Revision of the Li13Si4 structure.

Science.gov (United States)

Zeilinger, Michael; Fässler, Thomas F

2013-11-06

Besides Li17Si4, Li16.42Si4, and Li15Si4, another lithium-rich representative in the Li-Si system is the phase Li13Si4 (trideca-lithium tetra-silicide), the structure of which has been determined previously [Frank et al. (1975 ▶). Z. Naturforsch. Teil B, 30, 10-13]. A careful analysis of X-ray diffraction patterns of Li13Si4 revealed discrepancies between experimentally observed and calculated Bragg positions. Therefore, we redetermined the structure of Li13Si4 on the basis of single-crystal X-ray diffraction data. Compared to the previous structure report, decisive differences are (i) the introduction of a split position for one Li site [occupancy ratio 0.838 (7):0.162 (7)], (ii) the anisotropic refinement of atomic displacement parameters for all atoms, and (iii) a high accuracy of atom positions and unit-cell parameters. The asymmetric unit of Li13Si4 contains two Si and seven Li atoms. Except for one Li atom situated on a site with symmetry 2/m, all other atoms are on mirror planes. The structure consists of isolated Si atoms as well as Si-Si dumbbells surrounded by Li atoms. Each Si atom is either 12- or 13-coordinated. The isolated Si atoms are situated in the ab plane at z = 0 and are strictly separated from the Si-Si dumbbells at z = 0.5.

7Li(18O, 17N8Be reaction and the 17N + 8Be-potential

Directory of Open Access Journals (Sweden)

A. T. Rudchik

2010-12-01

Full Text Available Angular distributions of the 7Li(18O, 17N8Be reaction were measured for the transitions to the ground states of 8Be and 17N and excited states of 17N at the energy Elab(18O = 114 MeV. The data were analyzed with coupled-reaction-channels method for one- and two-step transfers of nucleons and clusters. In the analysis, the 7Li + 18O potential de-duced in the analysis of the elastic 7Li + 18O-scattering data as well as shell-model spectroscopic amplitudes of trans-ferred nucleons and clusters were used. Parameters of the 8Be + 17N potential were deduced using the reaction data. Contributions of different one- and two-step transfers in the 7Li(18O, 17N8Be reaction cross-section was studied.

Passivation behavior of Type 304 stainless steel in a non-aqueous alkyl carbonate solution containing LiPF6 salt

International Nuclear Information System (INIS)

Myung, Seung-Taek; Sasaki, Yusuke; Saito, Takamitsu; Sun, Yang-Kook; Yashiro, Hitoshi

2009-01-01

Passivation behavior of type 304 stainless steel in a non-aqueous alkyl carbonate solution containing LiPF 6 salt was studied using electrochemical polarization, X-ray photoelectron spectroscopy (XPS) and time of flight-secondary ion mass spectroscopy (ToF-SIMS). Cathodic polarization to 0 V vs. Li/Li + resulted in most but not complete reduction of the air-formed film from oxides to metal on the stainless steel, as confirmed by XPS. For complete elimination of the air-formed film, the surface of the stainless steel was scratched under anodic polarization conditions. At 3 V vs. Li/Li + where an anodic current peak appeared, only an indistinct layer was recognized on the newly scratched surface, according to ToF-SIMS analysis. Above 4 V vs. Li/Li + , substantial passive films were formed, which were composed of oxides and fluorides of iron and chromium. The origin of oxide was due to water contained in the non-aqueous alkyl carbonate solution, and that of fluorides were the result of the decomposition of electrolytic salt, LiPF 6 , especially at higher potential. The resultant passive films were stable in the non-aqueous alkyl carbonate solution containing LiPF 6 salt.

The solubility and site preference of Fe3+ in Li7−3xFexLa3Zr2O12 garnets

International Nuclear Information System (INIS)

Rettenwander, D.; Geiger, C.A.; Tribus, M.; Tropper, P.; Wagner, R.; Tippelt, G.; Lottermoser, W.; Amthauer, G.

2015-01-01

A series of Fe 3+ -bearing Li 7 La 3 Zr 2 O 12 (LLZO) garnets was synthesized using solid-state synthesis methods. The synthetic products were characterized compositionally using electron microprobe analysis and inductively coupled plasma optical emission spectroscopy (ICP-OES) and structurally using X-ray powder diffraction and 57 Fe Mössbauer spectroscopy. A maximum of about 0.25 Fe 3+ pfu could be incorporated in Li 7−3x Fe x La 3 Zr 2 O 12 garnet solid solutions. At Fe 3+ concentrations lower than about 0.16 pfu, both tetragonal and cubic garnets were obtained in the synthesis experiments. X-ray powder diffraction analysis showed only a garnet phase for syntheses with starting materials having intended Fe 3+ contents lower than 0.52 Fe 3+ pfu. Back-scattered electron images made with an electron microprobe also showed no phase other than garnet for these compositions. The lattice parameter, a 0 , for all solid-solution garnets is similar with a value of a 0 ≈12.98 Å regardless of the amount of Fe 3+ . 57 Fe Mössbauer spectroscopic measurements indicate the presence of poorly- or nano-crystalline FeLaO 3 in syntheses with Fe 3+ contents greater than 0.16 Fe 3+ pfu. The composition of different phase pure Li 7−3x Fe x La 3 Zr 2 O 12 garnets, as determined by electron microprobe (Fe, La, Zr) and ICP-OES (Li) measurements, give Li 6.89 Fe 0.03 La 3.05 Zr 2.01 O 12 , Li 6.66 Fe 0.06 La 3.06 Zr 2.01 O 12 , Li 6.54 Fe 0.12 La 3.01 Zr 1.98 O 12 , and Li 6.19 Fe 0.19 La 3.02 Zr 2.04 O 12 . The 57 Fe Mössbauer spectrum of cubic Li 6.54 Fe 0.12 La 3.01 Zr 1.98 O 12 garnet indicates that most Fe 3+ occurs at the special crystallographic 24d position, which is the standard tetrahedrally coordinated site in garnet. Fe 3+ in smaller amounts occurs at a general 96h site, which is only present for certain Li-oxide garnets, and in Li 6.54 Fe 0.12 La 3.01 Zr 1.98 O 12 this Fe 3+ has a distorted 4-fold coordination. - Graphical abstract: Cubic nominally Li 7 La 3 Zr 2 O

Charge carrier density in Li-intercalated graphene

KAUST Repository

Kaloni, Thaneshwor P.

2012-05-01

The electronic structures of bulk C 6Li, Li-intercalated free-standing bilayer graphene, and Li-intercalated bilayer and trilayer graphene on SiC(0 0 0 1) are studied using density functional theory. Our estimate of Young\\'s modulus suggests that Li-intercalation increases the intrinsic stiffness. For decreasing Li-C interaction, the Dirac point shifts to the Fermi level and the associated band splitting vanishes. For Li-intercalated bilayer graphene on SiC(0 0 0 1) the splitting at the Dirac point is tiny. It is also very small at the two Dirac points of Li-intercalated trilayer graphene on SiC(0 0 0 1). For all the systems under study, a large enhancement of the charge carrier density is achieved by Li intercalation. © 2012 Elsevier B.V. All rights reserved.

Mechanochemical transformations in Li(Na)AlH4-Li(Na)NH2 systems

International Nuclear Information System (INIS)

Dolotko, Oleksandr; Zhang Haiqiao; Ugurlu, Ozan; Wiench, Jerzy W.; Pruski, Marek; Scott Chumbley, L.; Pecharsky, Vitalij

2007-01-01

Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH 4 and LiNH 2 taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH 4 -NaNH 2 system after 60 min ball milling; and 5.2 wt.% H 2 is released when LiAlH 4 and NaNH 2 or NaAlH 4 and LiNH 2 are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH 4 (s) + MNH 2 (s) → 2MH(s) + AlN(s) + 2H 2 (g) was identified based on detailed spectroscopic analysis of the intermediate (M 3 AlH 6 ) and final products of the ball milling process

Microstructure and Mechanical Properties of Mg-11Li-6Zn-0.6Zr-0.4Ag-0.2Ca-x Y Alloys.

Science.gov (United States)

Kim, Yong-Ho; Yoo, Hyo-Sang; Son, Hyeon-Taek

2018-09-01

Magnesium and its alloys are potential candidates for many automotive and aerospace applications due to their low density and high specific strength. However, the use of magnesium as wrought products is limited because of its poor workability at ambient temperatures. Mg-Li alloys containing 5-11 wt.% Li exhibit a two-phase structure consisting of a α (hcp) Mg-rich phase and a β (bcc) Li-rich phase. Mg-Li alloys with Li content greater than 11 wt.% exhibit a single-phase structure consisting of only the β phase. In the present study, we studied the effects of Y addition on the microstructure and mechanical properties of Mg-11Li-6Zn-0.6Zr-0.4Ag-0.2Ca based alloys. The melt was maintained at 720 °C for 20 min and poured into a mold. Then, the as-cast Mg alloys were homogenized at 350 °C for 4 h and were hot-extruded onto a 4-mm-thick plate with a reduction ratio of 14:1. The as-cast Mg-11Li-6Zn-0.6Zr-0.4Ag-0.2Ca-xY (x 0, 1, 3, and 5 wt.%) alloys were composed of α-Mg, β-Li, γ-Mg2Zn3Li, I-Mg3YZn6, W-Mg3Y2Zn3, and X-Mg12YZn phases. By increasing the Y content from 0 to 5 wt.%, the composition of the W-Mg3Y2Zn3 phase increased. With increasing Y content, from 0 to 1, 3, and 5 wt.%, the average grain size and ultimate tensile of the as-extruded Mg alloys decreased slightly, from 8.4, to 3.62, 3.56, and 3.44 μm and from 228.92 to 215.57, 187.47, and 161.04 MPa, respectively, at room temperature.

Crystal structure of lithium disulfate, Li{sub 2}[S{sub 2}O{sub 7}], Li{sub 2}O{sub 7}S{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Logemann, Christian; Witt, Julia; Wickleder, Mathias S. [Oldenburg Univ. (Germany). Inst. of Pure and Applied Chemistry

2013-07-01

Li{sub 2}O{sub 7}S{sub 2}, orthorhombic, Pnma (no. 62), a = 13.177(2) Aa, b = 8.2516(7) Aa, c = 4.8547(4) Aa, V = 527.8 Aa{sup 3}, Z = 4, R{sub gt}(F) = 0.0338, wR{sub ref}(F{sup 2}) = 0.1054, T = 153 K.

Properties of LiBF[sub 4] and LiAsF[sub 6] solutions in mixtures of tetrahydrofuran and 2-methyltetrahydrofuran. Svojstva rastvorov LiBF[sub 4] i LiAsF[sub 6] v smesyakh tetragidrofurana i 2-metiltetragidrofurana

Energy Technology Data Exchange (ETDEWEB)

Plakhotnik, A V; Tovmash, N F; Mishustin, A I; Kokunov, Yu V [AN SSSR, Moscow (Russian Federation). Inst. Obshchej i Neorganicheskoj Khimii

1993-01-01

Solutions of lithium tetrafluoroborate and hexafluoroarsenate in mixtures of tetrahydrofuran and 2-methyltetrahydrofuran were studies by the methods of conductometry, densimetry, viscosimetry and measurement of spin-lattice relaxation rate on [sup 7]Li nuclei. Considerable ifluence of anion nature was ascertained. Assumptions are made on the presence of cooperative interaction involving formation of the structures from solvent molecules and salt ions.

First assessment of Li2O-Bi2O3 ceramic oxides for high temperature carbon dioxide capture

Institute of Scientific and Technical Information of China (English)

E.M.Briz-López; M.J.Ramírez-Moreno; I.C.Romero-Ibarra; C.Gómez-Yá(n)ez; H.Pfeiffer; J.Ortiz-Landeros

2016-01-01

The capacity to capture CO2 was determined in several stoichiometric compositions in the Li2O-Bi2O3 system.The compounds (Li7BiO6,Li5BiOs,Li3BiO4 and LiBiO2 phases) were synthesized via solid-state reaction and characterized by X-ray diffraction,scanning electron microscopy and N2 adsorption techniques.The samples were heat-treated at temperatures from 40 to 750 ℃ under the CO2 atmosphere to evaluate the carbonate formation,which is indicative of the capacity of CO2 capture.Moreover,Li7BiO6 shows an excellent CO2 capture capacity of 7.1 mmol/g,which is considerably higher than those of other previously reported ceramics.Li7BiO6 is able to react with CO2 from 240 ℃ to approximately 660 ℃ showing a high kinetic reaction even at CO2 partial pressure values as low as 0.05.

First assessment of Li2O–Bi2O3 ceramic oxides for high temperature carbon dioxide capture简

Institute of Scientific and Technical Information of China (English)

E.M.Briz-López; M.J.Ramírez-Moreno; I.C.Romero-Ibarra; C.Gómez-Yá?ez; H.Pfeiffer; J.Ortiz-Landeros

2016-01-01

The capacity to capture CO2 was determined in several stoichiometric compositions in the Li2O–Bi2O3 system. The compounds（Li7BiO6, Li5BiO5, Li3BiO4 and LiBiO2 phases） were synthesized via solid-state reaction and characterized by X-ray diffraction, scanning electron microscopy and N2 adsorption techniques.The samples were heat-treated at temperatures from 40 to 750 °C under the CO2 atmosphere to evaluate the carbonate formation, which is indicative of the capacity of CO2 capture. Moreover, Li7BiO6 shows an excellent CO2 capture capacity of 7.1 mmol/g, which is considerably higher than those of other previously reported ceramics. Li7BiO6 is able to react with CO2 from 240 °C to approximately 660 °C showing a high kinetic reaction even at CO2 partial pressure values as low as 0.05.

The preparation and properties of a novel electrolyte of electrochemical double layer capacitors based on LiPF6 and acetamide

International Nuclear Information System (INIS)

Li Qi; Zuo Xiaoxi; Liu Jiansheng; Xiao Xin; Shu Dong; Nan Junmin

2011-01-01

A novel electrolyte applied in electrochemical double-layer capacitors (EDLCs) has been prepared based on lithium hexafluorophosphate (LiPF 6 ) and acetamide and subsequently characterized by differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), electrochemical techniques and so on. The mixtures of LiPF 6 and acetamide at the molar ratios of 1:4 to 1:6 exist as liquids below 25 °C, which is attributed to the melting point depression of mixture and the coordination of the polar groups (C=O and NH groups) of acetamide with Li + and PF 6 − ions. The strong interaction between LiPF 6 and acetamide results in the rupture of the electrovalent bond of LiPF 6 and the breakage of hydrogen bonds among the acetamide molecules, leading to the formation of a liquid electrolyte. The LiPF 6 /acetamide electrolyte with a molar ratio of 1:5.5 exhibits a 5.2 V electrochemical window and suitable ionic conductivity at room temperature. In particular, the coin-type cells with carbon electrodes and LiPF 6 /acetamide electrolyte possess high thermal stability and electrochemical properties, showing that the as-prepared LiPF 6 /acetamide electrolyte is a promising candidate for EDLCs.

Low-temperature synthesis of Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} with cubic garnet-type structure

Energy Technology Data Exchange (ETDEWEB)

Xie, Hui [Texas Materials Institute, ETC 9.184, University of Texas at Austin, Austin, TX 78712 (United States); Li, Yutao [Texas Materials Institute, ETC 9.184, University of Texas at Austin, Austin, TX 78712 (United States); State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Goodenough, John B., E-mail: jgoodenough@mail.utexas.edu [Texas Materials Institute, ETC 9.184, University of Texas at Austin, Austin, TX 78712 (United States)

2012-05-15

Highlights: Black-Right-Pointing-Pointer One-step synthesis and its optimization of cubic garnet Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} at 750 Degree-Sign C. Black-Right-Pointing-Pointer Instability above 800 Degree-Sign C of the Al-free cubic Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12}. Black-Right-Pointing-Pointer Li{sup +}-ion conductivity without adventitious Al{sup 3+}. -- Abstract: In this paper, we report the direct synthesis of Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} with the cubic garnet-type structure at low temperature with a lattice constant of 13.0035 Angstrom-Sign . The synthesis condition is optimized to be at 750 Degree-Sign C for 8 h with 30 wt% excess lithium salt. No intermediate grinding was involved in this straightforward route. Without the adventitious of Al{sup 3+}, the cubic Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} is unstable above 800 Degree-Sign C and has an ionic conductivity of the order of 10{sup -6} S cm{sup -1}.

Peculiar Li-storage mechanism at graphene edges in turbostratic carbon black and their application in high energy Li-ion capacitor

Science.gov (United States)

Anothumakkool, Bihag; Dupré, Nicolas; Moreau, Philippe; Guyomard, Dominique; Brousse, Thierry; Gaubicher, Joel

2018-02-01

We report experimental evidence for the specific Li-storage at turbostratic graphene edges of a well-known and cheap Super P® carbon black (Csp) material, which is usually used as a conductive additive in composite electrodes. Indeed, operando XRD and HR-TEM consistently demonstrate Li insertion occurs with zero expansion of graphene layer up to a composition of Li0.4C6 (150 mA h/g) that is reached at 0.01 V vs. Li+/Li. 7Li NMR substantiates these results and suggests that the weak electronic transfer from the carbon host to the intercalant could help local reorganization of the layer order as suggested by the unexpected reversible changes of the (002) Bragg peak intensity during the charge-discharge process. Our observations also indicate this insertion mechanism is kinetically favored resulting in remarkable cycling stability over 1000 cycles and power capability allowing to sustain 110 mA h/g at 8 A/g (21 C) in half cell. The capability of Csp as an efficient anode is ultimately demonstrated in a lithium hybrid capacitor against a positive electrode of activated carbon. The full cell delivers a maximum energy of 120 Wh/kg (4.3-2 V) and remarkable capacity retention over 1800 cycles.

Importance of $1n$-stripping process in the $^{6}$Li+$^{159}$Tb reaction

OpenAIRE

Pradhan, M. K.; Mukherjee, A.; Roy, Subinit; Basu, P.; Goswami, A.; Kshetri, R.; Palit, R.; Parkar, V. V.; Ray, M.; Sarkar, M. Saha; Santra, S.

2013-01-01

The inclusive cross sections of the $\\alpha$-particles produced in the reaction $^{6}$Li+$^{159}$Tb have been measured at energies around the Coulomb barrier. The measured cross sections are found to be orders of magnitude larger than the calculated cross sections of $^{6}$Li breaking into $\\alpha$ and $d$ fragments, thus indicating contributions from other processes. The experimental cross sections of $1n$-stripping and $1n$-pickup processes have been determined from an entirely different me...

Role of the cluster structure of {sup 7}Li in the dynamics of fragment capture

Energy Technology Data Exchange (ETDEWEB)

Shrivastava, A., E-mail: aradhana@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Navin, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Diaz-Torres, A. [ECT, Villa Tambosi, I-38123 Villazzano, Trento (Italy); Nanal, V. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Ramachandran, K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Rejmund, M. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Bhattacharyya, S. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Chatterjee, A.; Kailas, S. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Lemasson, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Palit, R. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Parkar, V.V. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pillay, R.G. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Rout, P.C. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sawant, Y. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India)

2013-01-08

Exclusive measurements of prompt {gamma}-rays from the heavy-residues with various light charged particles in the {sup 7}Li + {sup 198}Pt system, at an energy near the Coulomb barrier (E/V{sub b}{approx}1.6) are reported. Recent dynamic classical trajectory calculations, constrained by the measured fusion, {alpha}- and t-capture cross-sections have been used to explain the excitation energy dependence of the residue cross-sections. These calculations distinctly illustrate a two-step process, breakup followed by fusion, in case of the capture of t and {alpha} clusters; whereas for {sup 6}He+p and {sup 5}He+d configurations, massive transfer is inferred to be the dominant mechanism. The present work clearly demonstrates the role played by the cluster structures of {sup 7}Li in understanding the reaction dynamics at energies around the Coulomb barrier.

Formation and control of zinc nitride in a molten LiCl-KCl-Li{sub 3}N system

Energy Technology Data Exchange (ETDEWEB)

Goto, Takuya; Toyoura, Kazuaki; Tsujimura, Hiroyuki; Ito, Yasuhiko

2004-08-25

We investigated a possibility of electrochemical formation and control of zinc nitride in a molten LiCl-KCl-Li{sub 3}N system at 673 K. Zinc nitride films were obtained by means of potentiostatic electrolysis of zinc electrodes in the melt. From XRD analysis, it was confirmed that obtained films consisted of Zn{sub 3}N{sub 2} and LiZnN and that the composition of each film was effected by the applied potential value. In the potential range from 0.75 to 1.6 V (versus Li{sup +}/Li), the ratio of Zn{sub 3}N{sub 2} increased as the applied potential was more positive. Based on the result, we achieved the formation of Zn{sub 3}N{sub 2} film (3-5 {mu}m) in anti-scandium oxide structure (a = 0.977 nm) by means of potentiostatic electrolysis at 1.6 V for 3 h.

Uniform second Li ion intercalation in solid state ϵ-LiVOPO4

International Nuclear Information System (INIS)

Wangoh, Linda W.; Quackenbush, Nicholas F.; Sallis, Shawn; Wiaderek, Kamila M.; Ma, Lu; Wu, Tianpin; Chapman, Karena W.; Lin, Yuh-Chieh; Ong, Shyue Ping; Wen, Bohua; Chernova, Natasha A.; Whittingham, M. Stanley; Guo, Jinghua; Lee, Tien-Lin; Schlueter, Christoph; Piper, Louis F. J.

2016-01-01

Full, reversible intercalation of two Li + has not yet been achieved in promising VOPO 4 electrodes. A pronounced Li + gradient has been reported in the low voltage window (i.e., second lithium reaction) that is thought to originate from disrupted kinetics in the high voltage regime (i.e., first lithium reaction). Here, we employ a combination of hard and soft x–ray photoelectron and absorption spectroscopy techniques to depth profile solid state synthesized LiVOPO 4 cycled within the low voltage window only. Analysis of the vanadium environment revealed no evidence of a Li + gradient, which combined with almost full theoretical capacity confirms that disrupted kinetics in the high voltage window are responsible for hindering full two lithium insertion. Furthermore, we argue that the uniform Li + intercalation is a prerequisite for the formation of intermediate phases Li 1.50 VOPO 4 and Li 1.75 VOPO 4 . The evolution from LiVOPO 4 to Li 2 VOPO 4 via the intermediate phases is confirmed by direct comparison between O K–edge absorption spectroscopy and density functional theory.

Measurement of the cross section of the 8Li(d,α)6He reaction of possible relevance to big bang nucleosynthesis

International Nuclear Information System (INIS)

Sahin, L.; Boyd, R.N.; Cole, A.L.; Famiano, M.; Gueray, R.T.; Murphy, A. St.J.; Oezkan, N.; Kolata, J.J.; Guimaraes, V.; Hencheck, M.

2002-01-01

We report measurements of the cross section of the 8 Li(d,α) 6 He reaction in the energy range E c.m. =2.3-3.5 MeV using a 8 Li-radioactive beam on a CD 2 foil. The astrophysical S factor and reaction rate were calculated from the measured cross section. The 6 He nuclei produced in the reaction were detected in solid-state detector telescopes. This reaction might have affected the primordial abundance of 6 Li in big bang nucleosynthesis, since 6 He beta decays to 6 Li. However, several big bang nucleosynthesis network calculations were found to be insensitive to this reaction, suggesting that the 8 Li(d,α) 6 He reaction does not affect 6 Li primordial production

Revision of the Li13Si4 structure

Directory of Open Access Journals (Sweden)

Thomas F. Fässler

2013-12-01

Full Text Available Besides Li17Si4, Li16.42Si4, and Li15Si4, another lithium-rich representative in the Li–Si system is the phase Li13Si4 (tridecalithium tetrasilicide, the structure of which has been determined previously [Frank et al. (1975. Z. Naturforsch. Teil B, 30, 10–13]. A careful analysis of X-ray diffraction patterns of Li13Si4 revealed discrepancies between experimentally observed and calculated Bragg positions. Therefore, we redetermined the structure of Li13Si4 on the basis of single-crystal X-ray diffraction data. Compared to the previous structure report, decisive differences are (i the introduction of a split position for one Li site [occupancy ratio 0.838 (7:0.162 (7], (ii the anisotropic refinement of atomic displacement parameters for all atoms, and (iii a high accuracy of atom positions and unit-cell parameters. The asymmetric unit of Li13Si4 contains two Si and seven Li atoms. Except for one Li atom situated on a site with symmetry 2/m, all other atoms are on mirror planes. The structure consists of isolated Si atoms as well as Si–Si dumbbells surrounded by Li atoms. Each Si atom is either 12- or 13-coordinated. The isolated Si atoms are situated in the ab plane at z = 0 and are strictly separated from the Si–Si dumbbells at z = 0.5.

Performance of LiAlloy/Ag(2)CrO(4) Couples in Molten CsBr-LiBr-KBr Eutectic

International Nuclear Information System (INIS)

GUIDOTTI, RONALD A.; REINHARDT, FREDERICK W.

1999-01-01

The performance of Li-alloy/CsBr-LiBr-KBr/Ag(sub 2)CrO(sub 4) systems was studied over a temperature range of 250 C to 300 C, for possible use as a power source for geothermal borehole applications. Single cells were discharged at current densities of 15.8 and 32.6 mA/cm(sup 2) using Li-Si and Li-Al anodes. When tested in 5-cell batteries, the Li-Si/CsBr-LiBr-KBr/Ag(sub 2)CrO(sub 4) system exhibited thermal runaway. Thermal analytical tests showed that the Ag(sub 2)CrO(sub 4) cathode reacted exothermically with the electrolyte on activation. Consequently, this system would not be practical for the envisioned geothermal borehole applications

VUV spectroscopy of Tm3+ and Mn2+ doped LiSrAlF6

International Nuclear Information System (INIS)

True, M.; Kirm, M.; Negodine, E.; Vielhauer, S.; Zimmerer, G.

2004-01-01

LiSrAlF 6 (LiSAF) crystals doped with either Tm 3+ or Mn 2+ were obtained by solid-state reaction and investigated spectroscopically using synchrotron radiation in the vacuum-ultra-violet and ultra-violet spectral regions. In the Tm 3+ doped LiSAF crystals, the slow spin-forbidden 5d-4f emission peaking at 166 nm with a lifetime of at least 1 μs was observed. The respective excitation spectrum consists of several bands in the range of 160-110 nm arising due to the 4f-5d absorption. The f-f emissions of Tm 3+ are well excited in the range of 135-110 nm, but not under excitation into the lower lying d-bands. The excitation mechanisms of different emissions will be discussed including the F - to Tm 3+ charge transfer excitation peaking at 127 nm in LiSAF. The characteristic broad 4 T 1 → 6 A 1 emission band of Mn 2+ peaking at 508 (504) nm was observed in LiSAF:Mn 2+ crystal at 10 (300) K. Three intense excitation bands, tentatively ascribed to the 3d-4s transitions of Mn 2+ , were revealed in the range of 170-110 nm

Electrochemical behavior of Li/LiV3O8 secondary cells

Science.gov (United States)

Bak, Hyo Rim; Lee, Jae Ha; Kim, Bok Ki; Yoon, Woo Young

2013-03-01

Li/LiV3O8 secondary cells with Li-foil and Li-powder anodes were fabricated, and their electrical properties were compared. Using the powder anode, a cell with an initial discharge capacity of 260 mAh g-1 that could be operated for over 100 cycles was obtained. The porous Li-powder electrode was safely synthesized by pressing an emulsion droplet onto an SUS mesh. A threefold increase in the electrical conductivity of the LiV3O8 cathode was achieved by the addition of carbon using a vibration pot mill. Using the powder anode resulted in 80% capacity retention at the 100th cycle, while that using the foil electrode was 46%; the 1.0 Crate/ 0.1 C-rate capacity ratio also increased from 44% to 60%. A cell employing the LiV3O8-carbon composite cathode showed better electrical performance, a capacity retention of 90% after 50 cycles, and an increase in rate capacity ratio. The crystal structure and morphology of the LiV3O8-C composite were investigated by x-ray diffraction and scanning electron microscopy.

Synthesis, crystal structure, and photocatalytic activity of a new two-layer Ruddlesden-Popper phase, Li2CaTa2O7

International Nuclear Information System (INIS)

Liang Zhenhua; Tang Kaibin; Shao Qian; Li Guocan; Zeng Suyuan; Zheng Huagui

2008-01-01

A new two-layer Ruddlesden-Popper phase Li 2 CaTa 2 O 7 has been synthesized for the first time. The detailed structure determination of Li 2 CaTa 2 O 7 performed by powder X-ray diffraction (XRD) and electron microscopy (ED) shows that it crystallizes in the space group Fmmm [a∼5.5153(1), b∼5.4646(1), c∼18.2375(3)A]. UV-visible diffuse reflection spectrum of the prepared Li 2 CaTa 2 O 7 indicates that it had absorption in the UV region. The photocatalytic activity of the Li 2 CaTa 2 O 7 powders was evaluated by degradation of RhB molecules in water under ultra visible light irradiation. The results showed that Li 2 CaTa 2 O 7 has high photocatalytic activity at room temperature. Therefore, the preparation and properties studies of Li 2 CaTa 2 O 7 with a two-layer Ruddlesden-Popper structure suggest potential future applications in photocatalysis. - Graphical abstract: Crystal structure of a two-layer Ruddlesden-Popper phase Li 2 CaTa 2 O 7 A new two-layer Ruddlesden-Popper phase Li 2 CaTa 2 O 7 has been synthesized for the first time. Li 2 CaTa 2 O 7 crystallizes in the space group Fmmm determined by powder X-ray and electron diffraction. UV-visible diffuse reflection spectra and the photocatalytic degradation of RhB molecules in water under ultra visible light irradiation show that Li 2 CaTa 2 O 7 is a potential material in photocatalysis

Search for resonant states in 10C and 11C and their impact on the primordial 7Li abundance

Science.gov (United States)

Hammache, F.; Coc, A.; de Séréville, N.; Stefan, I.; Roussel, P.; Assié, M.; Audouin, L.; Beaumel, D.; Franchoo, S.; Fernandez-Dominguez, B.; Fox, S.; Hamadache, C.; Kiener, J.; Laird, A.; Le Crom, B.; Lefebvre-Schuhl, A.; Lefebvre, L.; Matea, I.; Matta, A.; Mavilla, G.; Mrazek, J.; Morfouace, P.; de Oliveira Santos, F.; Parikh, A.; Perrot, L.; Sanchez-Benitez, A. M.; Suzuki, D.; Tatischeff, V.; Ujic, P.; Vandebrouck, Marine

2018-01-01

The cosmological 7Li problem arises from the significant discrepancy of about a factor 3 between the predicted primordial 7Li abundance and the observed one. The main process for the production of 7Li during Big-Bang nucleosynthesis is the decay of 7Be. Many key nuclear reactions involved in the production and destruction of 7Be were investigated in attempt to explain the 7Li deficit but none of them led to successful conclusions. However, some authors suggested recently the possibility that the destruction of 7Be by 3He and 4He may reconcile the predictions and observations if missing resonant states in the compound nuclei 10C and 11C exist. Hence, a search of these missing resonant states in 10C and 11C was investigated at the Orsay Tandem-Alto facility through 10B(3He,t)10C and 11B(3He,t)11C charge-exchange reactions respectively. After a short overview of the cosmological 7Li problem from a nuclear physics point of view, a description of the Orsay experiment will be given as well as the obtained results and their impact on the 7Li problem.

Role of LiNO3 in rechargeable lithium/sulfur battery

International Nuclear Information System (INIS)

Zhang, Sheng S.

2012-01-01

Highlights: ► Effect of LiNO 3 on the Li anode and cathode of Li/S battery is studied, respectively. ► LiNO 3 participates in the formation of a stable passivation film on the Li anode surface. ► LiNO 3 may be reduced irreversibly on the cathode, affecting Li/S battery performance. ► Discharge mechanism of Li/S battery is explained from the viewpoint of phase transition. - Abstract: In this work we study the effect of LiNO 3 on the Li anode and sulfur cathode, respectively, of Li/S battery by using a Li/Li symmetric cell and a liquid Li/Li 2 S 9 cell. On the Li anode, LiNO 3 participates in the formation of a stable passivation film, and the resulting passivation film grows infinitely with the consumption of LiNO 3 . The passivation film formed with LiNO 3 is known to effectively suppress the redox shuttle of the dissolved lithium polysulfides on Li anode. On the cathode, LiNO 3 undergoes a large and irreversible reduction starting at 1.6 V in the first discharge, and the irreversible reduction disappears in the subsequent cycles. Moreover, the insoluble reduction products of LiNO 3 on the cathode adversely affect the redox reversibility of sulfur cathode. These results indicate that both the Li anode and sulfur cathode consume LiNO 3 , and that the best benefit of LiNO 3 to Li/S battery occurs at the potentials higher than 1.6 V. By limiting the irreversible reduction of LiNO 3 on the cathode, we have shown that the Li/S cell with a 0.2 m LiNO 3 as the co-salt can provide a stable capacity of ∼500 mAh g −1 .

New insight on Li and B isotope fractionation during serpentinization derived from batch reaction investigations

Science.gov (United States)

Hansen, Christian T.; Meixner, Anette; Kasemann, Simone A.; Bach, Wolfgang

2017-11-01

Multiple batch experiments (100 °C, 200 °C; 40 MPa) were conducted, using Dickson-type reactors, to investigate Li and B partitioning and isotope fractionation between rock and water during serpentinization. We reacted fresh olivine (5 g; Fo90; [B] = anti-correlated with temperature, we argue for an overall attenuation of the isotopic effect through changes in B speciation in saline solutions (NaB(OH)4(aq) and B(OH)3Cl-) as well as variable B fixation and fractionation for different serpentinization product minerals (brucite, chrysotile). Breakdown of the Li-rich olivine and limited Li incorporation into product mineral phases resulted in an overall lower Li content of the final solid phase assemblage at 200 °C ([Li]final_200 °C = 0.77 μg/g; DS/FLi200 °C = 1.58). First order changes in Li isotopic compositions were defined by mixing of two isotopically distinct sources i.e. the fresh olivine and the fluid rather than by equilibrium isotope fraction. At 200 °C primary olivine is dissolved, releasing its Li budget into the fluid which shifts towards a lower δ7LiF of +38.62‰. Newly formed serpentine minerals (δ7LiS = +30.58‰) incorporate fluid derived Li with a minor preference of the 6Li isotope. At 100 °C Li enrichment of secondary phases exceeded Li release by olivine breakdown ([Li]final_100 °C = 2.10 μg/g; DS/FLi100 °C = 11.3) and it was accompanied by preferential incorporation of heavier 7Li isotope that might be due to incorporation of a 7Li enriched fluid fraction into chrysotile nanotubes.

α +d →6Li+γ astrophysical S factor and its implications for Big Bang nucleosynthesis

Science.gov (United States)

Grassi, A.; Mangano, G.; Marcucci, L. E.; Pisanti, O.

2017-10-01

The α +d →6Li +γ radiative capture is studied in order to predict the 6Li primordial abundance. Within a two-body framework, the α particle and the deuteron are considered the structureless constituents of 6Li. Five α +d potentials are used to solve the two-body problem: four of them are taken from the literature, only one having also a tensor component. A fifth model is here constructed in order to reproduce, besides the 6Li static properties as binding energy, magnetic dipole, and electric quadrupole moments, also the S -state asymptotic normalization coefficient (ANC). The two-body bound and scattering problem is solved with different techniques, in order to minimize the numerical uncertainty of the present results. The long-wavelength approximation is used, and therefore only the electric dipole and quadrupole operators are retained. The astrophysical S factor is found to be significantly sensitive to the ANC, but in all the cases in good agreement with the available experimental data. The theoretical uncertainty has been estimated of the order of few percent when the potentials which reproduce the ANC are considered, but increases up to ≃20 % when all five potential models are retained. The effect of this S -factor prediction on the 6Li primordial abundance is studied, using the public code PArthENoPE. For the five models considered here we find 6Li/H=(0.9 -1.8 ) ×10-14 , with the baryon density parameter in the 3-σ range of Planck 2015 analysis, Ωbh2=0.022 26 ±0.000 23 .

Resistivity switching properties of Li-doped ZnO films deposited on LaB_6 electrode

International Nuclear Information System (INIS)

Igityan, A.; Kafadaryan, Y.; Aghamalyan, N.; Petrosyan, S.; Badalyan, G.; Vardanyan, V.; Nersisyan, M.; Hovsepyan, R.; Palagushkin, A.; Kryzhanovsky, B.

2015-01-01

Current–voltage (I–V) characteristics of Al/p-ZnO:Li/LaB_6 device, measured in voltage sweep mode, show unipolar resistive switching and monostable threshold switching (URS and MTS) for different bias voltage polarities. URS could be transformed to MTS by application of reverse bias voltage. With increasing number of cycles, URS is converted to bipolar resistive switching mode which is lost after certain number of cycles, and device turns into an ordinary resistor. Analysis of linear fitting I–V curves suggests that ohmic and space charge limited current laws are responsible for conductivity mechanism of Al/p-ZnO:Li/LaB_6 device. - Highlights: • Al/p-ZnO:Li/LaB_6 memristive device is fabricated using an e-beam evaporation technique. • Current–voltage (I–V) characteristics are studied. • Type of resistive switching mode depends on the bias voltage polarity and number of switching cycles. • Resistive switching in Al/ZnO:Li/LaB_6 has an interfacial effect. • Ohmic and SCLC laws are responsible for conductivity mechanism of resistive states.

Wavelength-shifting fiber signal readout from Transparent RUbber SheeT (TRUST) type LiCaAlF6 neutron scintillator

International Nuclear Information System (INIS)

Watanabe, Kenichi; Yamazaki, Takuya; Sugimoto, Dai; Yamazaki, Atsushi; Uritani, Akira; Iguchi, Tetsuo; Fukuda, Kentaro; Ishidu, Sumito; Yanagida, Takayuki; Fujimoto, Yutaka

2015-01-01

As an alternative to the standard 3 He neutron detector, we are developing the Transparent RUbber SheeT type (TRUST) Eu doped LiCaAlF 6 (Eu:LiCAF) scintillator. This type of neutron scintillator can easily be fabricated as a large area sheet. In order to take advantage of a large area detector, we try to readout scintillation photons using a wavelength-shifting fiber (WLSF) from a TRUST Eu:LiCAF scintillator. The TRUST Eu:LiCAF scintillator with the size of 50×50×5 mm 3 was mounted on the WLSF plate and the end of the WLSFs was connected with a PMT. In order to reject high pulse height events induced in the WLSFs, we applied the pulse shape discrimination technique. The gamma-ray intrinsic and neutron absolute detection efficiency is evaluated to be 8.8×10 −7 and 9×10 −3 cps/ng Cf (2 m) for the TRUST Eu:LiCAF scintillator with the size of 50×50×5 mm 3

Quantum-Chemical Approach to NMR Chemical Shifts in Paramagnetic Solids Applied to LiFePO4 and LiCoPO4.

Science.gov (United States)

Mondal, Arobendo; Kaupp, Martin

2018-04-05

A novel protocol to compute and analyze NMR chemical shifts for extended paramagnetic solids, accounting comprehensively for Fermi-contact (FC), pseudocontact (PC), and orbital shifts, is reported and applied to the important lithium ion battery cathode materials LiFePO 4 and LiCoPO 4 . Using an EPR-parameter-based ansatz, the approach combines periodic (hybrid) DFT computation of hyperfine and orbital-shielding tensors with an incremental cluster model for g- and zero-field-splitting (ZFS) D-tensors. The cluster model allows the use of advanced multireference wave function methods (such as CASSCF or NEVPT2). Application of this protocol shows that the 7 Li shifts in the high-voltage cathode material LiCoPO 4 are dominated by spin-orbit-induced PC contributions, in contrast with previous assumptions, fundamentally changing interpretations of the shifts in terms of covalency. PC contributions are smaller for the 7 Li shifts of the related LiFePO 4 , where FC and orbital shifts dominate. The 31 P shifts of both materials finally are almost pure FC shifts. Nevertheless, large ZFS contributions can give rise to non-Curie temperature dependences for both 7 Li and 31 P shifts.

Pressure-composition isotherms and thermodynamic properties of TiF3-enhanced Na2LiAlH6

International Nuclear Information System (INIS)

Fossdal, A.; Brinks, H.W.; Fonnelop, J.E.; Hauback, B.C.

2005-01-01

The mixed alanate Na 2 LiAlH 6 was prepared by ball-milling and subsequent heat-treatment under H 2 pressure. After the synthesis, 2 mol% TiF 3 was added by ball-milling. Pressure-composition isotherms were measured for the Ti-enhanced material in the temperature range of 170-250 deg C. A van't Hoff plot was constructed using the equilibrium desorption plateau pressures. From this plot, a dissociation enthalpy of 56.4 ± 0.4 kJ/mol H 2 and a corresponding entropy of 137.9 ± 0.7 J/K mol H 2 was found for Na 2 LiAlH 6

Trinucleon cluster knockout from 6Li

International Nuclear Information System (INIS)

Connelly, J.P.; Berman, B.L.; Briscoe, W.J.; Dhuga, K.S.; Mokhtari, A.; Zubanov, D.; Blok, H.P.; Ent, R.; Mitchell, J.H.; Lapikas, L.

1998-01-01

The momentum-transfer dependence of the 3 H and 3 He knockout reactions from 6 Li via exclusive electron scattering has been measured, and the two reactions are compared. In the absence of two-step processes, the ratio of the fivefold cross sections for these mirror reactions should simply scale by the ratio of the 3 H and 3 He electron-scattering cross sections. A significant deviation from this simple expectation is seen at low momentum transfer. Possible explanations for this dramatic difference in cross sections for these mirror reactions are discussed. copyright 1998 The American Physical Society

Guided Lithium Metal Deposition and Improved Lithium Coulombic Efficiency through Synergistic Effects of LiAsF ₆ and Cyclic Carbonate Additives

Energy Technology Data Exchange (ETDEWEB)

Ren, Xiaodi [Energy; Zhang, Yaohui [Energy; Engelhard, Mark H. [Environmental; Li, Qiuyan [Energy; Zhang, Ji-Guang [Energy; Xu, Wu [Energy

2017-11-20

Spatial and morphology control over lithium (Li) metal nucleation/growth, as well as improving Li Coulombic efficiency (CE) are of the most challenging issues for rechargeable Li metal batteries. Here, we report that LiAsF6 and vinylene carbonate (VC) can work synergistically to address these challenges. It is revealed that AsF6- can be reduced to Li3As and LiF, which can act as seeds for Li growth and form a robust solid electrolyte interphase (SEI) layer, respectively. The addition of VC is critical because it not only enables uniform AsF6- reduction by passivating the defect sites on Cu substrate, but also improves the SEI layer flexibility during the reductive polymerization process. As a result, highly compact, uniform and dendrite-free Li film with vertically aligned columns structure can be obtained with greatly increased Li CE, and the Li metal batteries using the electrolyte with both LiAsF6 and VC additives can have much improved cycle life.

7Li breakup polarization potential at near barrier energies

International Nuclear Information System (INIS)

Lubian, J. . E-mail lubian@if.uff.br; Correa, T.; Paes, B.; Figueira, J.M.; Abriola, D.; Fernandez Niello, J.O.; Arazi, A.; Capurro, O.A.; de Barbara, E.; Marti, G.V.; Martinez Heinmann, D.; Negri, A.E.; Pacheco, A.J.; Padron, I.; Gomes, P.R.S.

2007-01-01

Inelastic and one neutron transfer cross sections at energies around the Coulomb barrier were used to derive dynamic polarization potential (DPP) for the 7 Li + 27 Al system. The DPP due to breakup, obtained in a simple way, indicates that its real part is repulsive at near barrier energies

Characteristics of new LiF preparations and sensitised LiF

Energy Technology Data Exchange (ETDEWEB)

Driscoll, C M.H.; O' Hagan, J B; Mundy, S J; Todd, C D; McWhan, A F; Dodson, J

1986-01-01

The patent governing the preparation and production of lithium fluoride (LiF) awarded to the Harshaw Chemical Co. has expired. Other companies have become interested in developing additional preparations of this material. Two of these preparations include LiF:Mg,Ti manufactured by Vinten Instruments plc and high sensitivity LiF:Mg, Cu,P distributed by them. The properties of these materials, including sensitivity, dose threshold, photon energy response, reusability and storage characteristics, are presented in this paper and compared with those of Harshaw TLD-100 and with those of sensitised LiF.

Neutron Energy Spectra and Yields from the 7Li(p,n) Reaction for Nuclear Astrophysics

Science.gov (United States)

Tessler, M.; Friedman, M.; Schmidt, S.; Shor, A.; Berkovits, D.; Cohen, D.; Feinberg, G.; Fiebiger, S.; Krása, A.; Paul, M.; Plag, R.; Plompen, A.; Reifarth, R.

2016-01-01

Neutrons produced by the 7Li(p, n)7Be reaction close to threshold are widely used to measure the cross section of s-process nucleosynthesis reactions. While experiments have been performed so far with Van de Graaff accelerators, the use of RF accelerators with higher intensities is planned to enable investigations on radioactive isotopes. In parallel, high-power Li targets for the production of high-intensity neutrons at stellar energies are developed at Goethe University (Frankfurt, Germany) and SARAF (Soreq NRC, Israel). However, such setups pose severe challenges for the measurement of the proton beam intensity or the neutron fluence. In order to develop appropriate methods, we studied in detail the neutron energy distribution and intensity produced by the thick-target 7Li(p,n)7Be reaction and compared them to state-of- the-art simulation codes. Measurements were performed with the bunched and chopped proton beam at the Van de Graaff facility of the Institute for Reference Materials and Measurements (IRMM) using the time-of-flight (TOF) technique with thin (1/8") and thick (1") detectors. The importance of detailed simulations of the detector structure and geometry for the conversion of TOF to a neutron energy is stressed. The measured neutron spectra are consistent with those previously reported and agree well with Monte Carlo simulations that include experimentally determined 7Li(p,n) cross sections, two-body kinematics and proton energy loss in the Li-target.

Developing New Electrolytes for Advanced Li-ion Batteries