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Sample records for ba ce sm

  1. Investigation of GdBaCo2-xFexO6-δ (x = 0, 0.2) - Ce0.8Sm0.2O2 composite cathodes for intermediate temperature solid oxide fuel cells

    Science.gov (United States)

    Tsvetkova, N. S.; Zuev, A. Yu.; Tsvetkov, D. S.

    2013-12-01

    The double perovskites GdBaCo2-xFexO6-δ (x = 0, 0.2) and composites (100 - y) GdBaCo2-xFexO6-δ (x = 0, 0.2) - y Ce0.8Sm0.2O2 (y = 10-50 wt.%) were investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). Chemical compatibility of GdBaCo2-xFexO6-δ (x = 0, 0.2) with solid electrolyte Ce0.8Sm0.2O2, thermal expansion, DC conductivity and electrochemical performance of (100 - y) GdBaCo2-xFexO6-δ (x = 0, 0.2) - y Ce0.8Sm0.2O2 (y = 10-50 wt.%) were studied. Partial substitution of Fe for Co was shown to lead to decrease of double perovskite GdBaCo2-xFexO6-δ reactivity with the solid electrolyte Ce0.8Sm0.2O2. Polarization resistance of cathodes studied was found to depend significantly on firing temperature. Variation of solid electrolyte content in (100 - y) GdBaCo2-xFexO6-δ (x = 0, 0.2) - y Ce0.8Sm0.2O2 (y = 10-50 wt.%) composites was shown to allow to optimize their electrochemical performance. Cathode materials of 80 wt.% GdBaCo2O6-δ - 20 wt.% Ce0.8Sm0.2O2 and 65 wt.% GdBaCo1.8Fe0.2O6-δ - 35 wt.% Ce0.8Sm0.2O2 were found to have the lowest polarization resistances and reasonable values of thermal expansion coefficient (TEC) and, therefore, can be considered as promising cathode materials for IT-SOFCs.

  2. Preparation and electrochemical performances of LaBaCo2O5 +δ-Ce0.8Sm0.2O1.9 graded composite cathode%梯度复合阴极LaBaCo2O5+δ-Ce0.8Sm0.2O1.9的制备及电化学性能

    Institute of Scientific and Technical Information of China (English)

    李瑞锋; 陈涵; 郭露村

    2012-01-01

    采用机械混合法制备中温固体氧化物燃料电池梯度复合阴极材料LaBaCo2O5+δ-Ce0.8Sm0.2O1.9(LBCO - SDC).通过X线衍射(XRD)分析、扫描电镜(SEM)分析、热膨胀法、交流阻抗谱法和循环伏安法分别对晶体结构、界面微观结构、热膨胀性及电化学性能进行表征.结果表明:LBCO阴极与SDC电解质之间具有良好的化学相容性;电解质SDC的添加有效地降低了阴极材料LBCO的热膨胀系数;双层梯度复合阴极比单层阴极表现出更小的比表面电阻以及极化过电位,显示出更好的电化学性能;在700℃时,双层梯度复合阴极的比表面电阻与LBCO阴极相比下降了约13.2%,极化过电位(电流密度为0.20 A/cm2)从51.0 mV下降到46.4 mV.%The LaBaCo205+δ-Ce0.8Sm0201. 9(LBC0-SDC) graded composite cathode for intermediate temperature solid oxide fuel cells was prepared by a mechanical mixing method. The crystal structure, interfacial microstructure,thermal expansion, and electrochemical performances were investigated by X-ray diffraction (XRD) ,scanning electron microscopy(SEM) ,dilatometry, AC impedance, and cyclic voltamme-try techniques. Results showed that the LBCO cathode had good chemical compatibility with the SDC electrolyte. The addition of SDC electrolyte to LBCO cathode could effectively reduce its thermal expansion coefficient. The double-layer graded composite cathode exhibited smaller area-specific resistance and polarization overpotential than the monolayer cathode, thus showing the better electrochemical performance. For graded composite cathode,the area-specific resistance value was about 13. 2% lower than that of LBCO at 700 t ,and the cathodic overpotential was decreased from 51.0 mV to 46. 4 mV at a current density of0. 20 A/cm2.

  3. Synthesis and characterization of BaCeO3 nanocrystals viasolvothermal-based method

    Institute of Scientific and Technical Information of China (English)

    XU Chao; ZHU Junwu; YANG Xujie; LU Lude; WANG Xin

    2008-01-01

    A facile approach to preparing well-dispersed nanocrystals of BaCeO3 was developed by a combination of solvothermal and annealing processes. The precursor consisted of amorphous BaCO3 and CeO2, and the conversion of the precursor to crystalline BaCeO3 nanocrystals occurred upon heat treatment at a relatively low temperature. The as-processed BaCeO3 had an orthorhombic structure and the average size of such crystals was approximately 80 nm. The obtained products were characterized by Fourier Transform Infrared (FT-IR), X-Ray Diffraction (XRD), Laser Raman Spectroscopy (LRS), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectrometry (EDS), and Transmission Electron Microscopy (TEM). This preparation process could also be used to synthesize doped barium cerate complex oxides BaCe0.95M0.05O3-d (M=Y, Nd, Gd, and Sm).

  4. 中温固体氧化物燃料电池SmBaCo_2O_(5+δ)–Sm_(0.2)Ce_(0.8)O_(1.9)复合阴极材料的电化学性能%Electrochemical Performance of SmBaCo2O5+δ-Sm0.2Ce0.8O1.9 Composite-Cathode for Intermediate Temperature Solid Oxide Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    王小连; 丁岩芝; 林彬; 卢肖永; 陈永红

    2012-01-01

    The cathode powder of double perovskites-type SmBaCo 2 O 5+δ(SBCO) and electrolyte powder of fluorite-structure Sm 0.2 Ce 0.8 O 1.9(SDC) were synthesized by a citric acid-nitrates self-propagating combustion method.The composite-cathode was obtained by mixing and grinding the SBCO and SDC powders at a mass ratio of 3:2.The chemical compatibility,electrical conductivity and thermal expansion coefficient(TEC) of the composite-cathode(SBCO-SDC) were characterized by X-ray diffraction,direct current four-terminal method and thermal dilatometry,respectively.An anode-supporting fuel cell of Ni-SDC|SDC|SBCO-SDC was fabricated and the performance of the cell was analyzed.The cross-section microstructure and polarization of the cell were investigated using a scanning electron microscope(SEM) and AC impedance spectroscopy.The results indicate that there are no interactions between SBCO and SDC at 1 000 ℃.The electrical conductivity of the SBCO-SDC composite-cathode reached to 369–234 S/cm at 450–800 ℃.The addition of SDC decreased the TEC of the composite-cathode.The single cell has an ideal microstructure and a good interface among anode,electrolyte and cathode.The polarization resistance of the electrodes was 0.031.cm 2 at 650 ℃.The cell with an open-circuit potential of 0.77 V and a maximum output power density of 640 mW/cm 2 was obtained when the humidified(about 3% H 2 O) hydrogen as a fuel and air as oxidant were used at 650 ℃.It was demonstrated that the SBCO-SDC composite-cathode could be used as a potential candidate cathode for intermediate temperature solid oxide fuel cell.%采用柠檬酸–硝酸盐自蔓延燃烧法分别合成了双钙钛矿结构的SmBaCo2O5+δ(SBCO)阴极粉体和萤石型Sm0.2Ce0.8O1.9(SDC)电解质粉体,按3:2的质量比混合上述粉体研磨后得到复合阴极。利用X射线衍射仪研究化学相容性,直流四端子法测量电导率,热膨胀仪测量热膨胀系数;构建阳极支撑型单电池(Ni

  5. Electrochemical impedance spectroscopy of BaCeO{sub 3} modified by Ti and Y

    Energy Technology Data Exchange (ETDEWEB)

    Pasierb, P.; Wierzbicka, M.; Komornicki, S.; Rekas, M. [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Al. Mickiewicza 30, 30-059 Krakow (Poland)

    2009-10-20

    Barium cerate exhibits high protonic conductivity, especially when modified by trivalent dopant such as Y, Yb, Nd, Sm or Dy. Unfortunately, the poor chemical stability in the presence of CO{sub 2} is the main disadvantage of this material. One of the possible approach to get the stable protonic conductor is the preparation of solid solutions. For example, doping of BaCeO{sub 3} with Zr leads to the improvement of the chemical stability, but the electrical properties are simultaneously corrupted. In the present work the influence of Ti, per analogy to Zr, and Y dopants on electrical properties of BaCeO{sub 3} was investigated using the electrochemical impedance spectroscopy (EIS) technique. BaCe{sub 1-x}Ti{sub x}O{sub 3-{delta}} (0 {<=} x {<=} 0.3) and Ba(Ce{sub 0.95}Ti{sub 0.05}){sub 0.95}Y{sub 0.05}O{sub 3-{delta}} solid electrolytes were prepared by solid-state reaction method. It was found that the changes of electrical properties due to the introduction of Ti into the BaCeO{sub 3} lattice is caused predominantly by the modification of the grain boundary properties. The Ti doping leads to the substantial decrease of grain boundary electrical conductivity, comparing to undoped material. The introduction of yttrium dopant to the BaCe{sub 0.95}Ti{sub 0.05}O{sub 3} lattice has the opposite effect. The total electrical conductivity increases, due to significant modification of grain boundary electrical properties. (author)

  6. Cobalt-free Composite Ba0.5Sr0.5Fe0.9Ni0.1O3-δ-Ce0.8Sm0.2O2-δ as Cathode for Intermediate-Temperature Solid Oxide Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    Xiangfeng Chu; Feng Liu; Weichang Zhu; Yongping Dong; Mingfu Ye; Wenqi Sun

    2012-01-01

    New cobalt-free composites consisting of Ba0.5Sr0.5Fe0.9Ni0.1O3-δ (BSFN) and Ce0.8Sm0.2O2-δ (SDC) were investigated as possible cathode materials for intermediate-temperature solid oxide fuel cell (IT-SOFC). BSFN, which was synthesized by auto ignition process, was chemically compatible with SDC up to 1100 ℃ as indicated by X-ray diffraction analysis. The electrical conductivity of BSFN reached the maximum value of 57 S.cm-1 at 450 ℃. The thermal expansion coefficient (TEC) value of BSFN was 30.9×10-6 K-1, much higher than that of typical electrolytes. The electrochemical behavior of the composites was analyzed via electrochemical impedance spectroscopy with symmetrical cells BSFN-SDC/SDC/BSFN-SDC. The area specific interracial polarization resistance (ASR) decreased with increasing SDC content of the composite. The area specific interracial polarization resistance (ASR) at 700 ℃ is only 0.49, 0.34 and 0.31 Ω.cm2 when 30, 40, and 50 wt% SDC was cooperated to BSFN, respectively. These results suggest that BSFN-SDC is a possible candidate for IT-SOFC cathode.

  7. Fluorite Ce0.8Sm0.2O2δ porous layer coating to enhance the oxygen permeation behavior of a BaCo0.7Fe0.2Nb0.1O3δ mixed conductor

    Institute of Scientific and Technical Information of China (English)

    Tai-he Wang; Wei-jia Song; Rong Li; Qiang Zhen

    2016-01-01

    Fluorite Ce0.8Sm0.2O2-δ (SDC) nanopowder with a crystallite size of 15 nm was synthesized by a co-precipitation method. An SDC porous layer was coated onto a BaCo0.7Fe0.2Nb0.1O3-d (BCFN) mixed conductor to improve its oxygen transport behavior. The results show that the SDC-coated BCFN membrane exhibits a remarkably higher oxygen permeation flux (JO2) than the uncoated BCFN in the partial oxidation of coke oven gas (COG). The maximumJO2 value of the SDC-coated BCFN is 18.28 mL·min-1·cm-2 under a COG/air flux of 177 mL·min-1/353 mL·min-1 at 875°C when the thickness of the BCFN membrane is 1 mm; thisJO2 value is 23% higher than that of the uncoated BCFN membrane. This enhancement is likely because of the higher oxygen ionic conductivity of SDC, which supplies oxygen va-cancies and accelerates oxygen exchange on the membrane/coating layer/gas three-phase boundary.

  8. Fluorite Ce0.8Sm0.2O2- δ porous layer coating to enhance the oxygen permeation behavior of a BaCo0.7Fe0.2Nb0.1O3- δ mixed conductor

    Science.gov (United States)

    Wang, Tai-he; Song, Wei-jia; Li, Rong; Zhen, Qiang

    2016-06-01

    Fluorite Ce0.8Sm0.2O2- δ (SDC) nanopowder with a crystallite size of 15 nm was synthesized by a co-precipitation method. An SDC porous layer was coated onto a BaCo0.7Fe0.2Nb0.1O3- δ (BCFN) mixed conductor to improve its oxygen transport behavior. The results show that the SDC-coated BCFN membrane exhibits a remarkably higher oxygen permeation flux ({J_{{O_2}}}) than the uncoated BCFN in the partial oxidation of coke oven gas (COG). The maximum {J_{{O_2}}} value of the SDC-coated BCFN is 18.28 mL·min-1·cm-2 under a COG/air flux of 177 mL·min-1/353 mL·min-1 at 875°C when the thickness of the BCFN membrane is 1 mm; this {J_{{O_2}}} value is 23% higher than that of the uncoated BCFN membrane. This enhancement is likely because of the higher oxygen ionic conductivity of SDC, which supplies oxygen vacancies and accelerates oxygen exchange on the membrane/coating layer/gas three-phase boundary.

  9. Assessment of microseeds biodegradability of Sm and Sm:Ba splenic implants in rabbits

    International Nuclear Information System (INIS)

    The radioactive interstitial implants have applications in controlling neoplasm in several regions of the human body. Currently the permanent brachytherapy seeds implanted in the spleen and other organs are made of I-125 seeds. After the total emission of radiation, the metal encapsulated seed remains inert in the implanted area. Seeds of bioactive ceramics have been prepared with Sm-152 incorporation to be activated in Sm-153. This study aimed to develop surgical technique for implanting biodegradable micro-seeds in the spleen of the rabbit. Three micro-seeds were introduced by hypodermic needle in the spleen in eight rabbits by median laparotomy. Subsequently, there were clinical and functional reactions of the animal to the implanted foreign body. The other objective was to perform the animal monitoring by radiography, produced in time sequence, and pathological studies of a fragment of the spleens of rabbits. The results show the effectiveness of surgery, the identification of the implanted material by radiography in vivo, and the biocompatibility of micro-seeds most of Sm and Sm:Ba. These seeds of reduced volume, 0.3x 1.6 mm, could be monitored for radiological studies in 2 periods: early and later implant. On the later studies, radiography was taken at 60d post-implant. Biopsies were taken and radiographs of the samples were also performed for evidencing the degradation state of the seeds. The results of the two groups of four rabbits are presented. They show partial degradation of the seed verified by radiographic contrast which is related to the atomic number of the elements and mass density in the seed. The biopsy showed that the ceramic is clearly absorbed by the spleen tissue and form tissue-implant interface. The histological slides showed an inflammatory reaction with presence of fibrosis of the giant cell foreign body. In conclusion, the radiograph shows a suitable noninvasive technique for monitoring the degradation of micro-seed ceramics in vivo

  10. Irradiation-induced reduction and luminescence properties of Sm2+ doped in BaBPO5

    International Nuclear Information System (INIS)

    Usually, Sm2+ ions could be reduced by heating the materials in reducing atmospheres. Exposure to ionizing radiations is also known to cause Sm3+→Sm2+ conversion. In this work, BaBPO5 doped with the samarium ion was prepared by high temperature solid-state reaction. Sm2+ ions were obtained by two different reduction methods, i.e., heating in H2 reduced atmosphere and X-ray irradiation. The measurements of X-ray diffraction (XRD), and scanning electron microscope (SEM) were investigated. It is found that the conversion of Sm3+→Sm2+ is very efficient in BaBPO5 hosts after X-ray irradiation. Sm2+ ions under these two reduction methods exhibit different characteristics that were studied by measurements of luminescence and decay. The results showed that the luminescence properties of Sm2+ ions in BaBPO5 were highly dependent on the sample preparation conditions. - Graphical abstract: The Sm doped in BaBPO5 as-prepared in air contains only Sm3+ ions and shows its fluorescence bands due to the 4G5/2 to 6H5/2, 6H7/2, 6H9/2, and 6H11/2 transitions (a) under the excitation of 488 nm Ar+-ion laser. The emission spectra of the samples after X-ray subsequentially irradiations are characteristic of Sm2+ transitions between the energy levels of 4f6 electronic configurations (b). It is found that the conversion of Sm3+→Sm2+ is very efficient in BaBPO5 hosts after X-ray irradiation

  11. Spectroscopy and luminescence dynamics of Ce3+ and Sm3+ in LiYSiO4

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Rui; Xu, Jinzhong; Liu, Guokui; Zhang, Xuejie; Zhou, Weihie; Pan, Fengjuan; Huang, Yan; Tao, Ye; Liang, Hongbin

    2016-03-03

    The lithium yttrium silicate series of LiY1-xLnxSiO4 exhibits superb chemical and optical properties, and with Ln = Ce3+, Sm3+, its spectroscopic characteristics and luminescence dynamics are investigated in the present work. Energy transfer and non-radiative relaxation dramatically influence the Ln3+ luminescence spectra and decay dynamics, especially in the Ce3+-Sm3+ co-doped phosphors. It is shown that thermal-quenching of the blue Ce3+ luminescence is primarily due to thermal ionization in the 5d excited states rather than multi-phonon relaxation, whereas cross-relaxation arising from electric dipole-dipole interaction between adjacent Sm3+ ions is the leading mechanism that quenches the red Sm3+ luminescence. In the co-doped systems, Ce3+-Sm3+ energy transfer in competing with the thermal quenching enhance the emission from Sm3+. The combined influences of concentration quenching, thermal ionization, energy transfer including cross-relaxation on the luminescence intensity of single-center and co-doped phosphors are analyzed based on the theories of ion-ion and ion-lattice interactions.

  12. Hydrothermal synthesis and luminescent properties of BaMoO4:Sm3+ red phosphor

    Institute of Scientific and Technical Information of China (English)

    李兆; 王永锋; 曹静; 江元汝; 赵西成; 孟志新

    2016-01-01

    Trivalent samarium doped barium molybdate (BaMoO4:Sm3+) red phosphor was successfully synthesized by hydrothermal method. The crystal structure, morphology and photoluminescent property were characterized by X-ray diffraction, field environ-mental scanning electron microscopy and photoluminescence spectroscopy. The results indicated that the synthesized BaMoO4:Sm3+ phosphor consisted of a pure phase with an octahedral structure. The main excitation peaks were located at 362, 404, 445 and 477 nm, respectively, and were obviously observed. The main emission peaks were located at 533, 566, 602 and 646 nm, respectively. The phosphors exhibited a red performance at 646 nm, which was appropriate for the ultraviolet-light emitting diode (UV-LED) and blue LED. The luminescent intensity of BaMoO4:Sm3+ increased with an increase in the doping amount of Sm3+. The luminescent intensity had the optimal value forx=0.03. When the doping amount of Sm3+ was further increased, the concentration quenching phenomenon was observed. Monovalent lithium (Li+) cation was used as a charge compensator. The luminescence intensity first increased with in-creasing Li+ doping concentration, and then decreased. The optimal content of Li+ was about 2%. The BaMoO4:Sm3+ phosphor pre-pared in this study could act as superior red phosphor for white LEDs.

  13. Relaxation kinetics of Sm: Ce-doped CaS phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Paulose, P.I. [Research Centre, Department of Physics, Maharajas College, Ernakulam 682011 (India); Joseph, James [St. Pauls College, Kalamassery, Ernakulam (India); Rudra Warrier, M.K. [Research Centre, Department of Physics, Maharajas College, Ernakulam 682011 (India); Jose, Gijo [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India); Unnikrishnan, N.V. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India)], E-mail: nvu50@yahoo.co.in

    2007-12-15

    Different samples of calcium sulphide (CaS):CaS(Sm) and CaS(Sm,Ce) phosphors have been prepared. To study the phosphorescence decay systematically, the samples were excited to a saturation using 259 nm line of xenon lamp and phosphorescence emission was monitored for a wavelength 569 nm of samarium. The trap depth has been evaluated by analyzing the decay curves. The observed decay could be explained satisfactorily by assuming a superposition scheme. The thermoluminescence properties of the doped CaS phosphors are also investigated in detail by computerized deconvolution technique of the glow curves obtained by UV irradiation.

  14. Preparation of double-doped BaCeO3 and its application in the synthesis of ammonia at atmospheric pressure

    Directory of Open Access Journals (Sweden)

    ZhiJie Li et al

    2007-01-01

    Full Text Available Perovskite-type oxides BaCe0.90Sm0.10O3−δ (BCS and BaCe0.80Gd0.10Sm0.10O3−δ (BCGS were synthesized by the sol–gel method and characterized by thermal analysis (TG-DTA, X-ray diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. Using the sintered samples as solid electrolytes and silver–palladium alloy as electrodes, ammonia was synthesized from nitrogen and hydrogen at atmospheric pressure in a solid-state proton-conducting cell reactor. The maximum rate of production of ammonia was 5.82×10−9 mol s−1 cm−2.

  15. On the PL, TSL and OSL properties of SrS:Ce,Sm phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Lapraz, Dominique; Angellier, Gaelle [Laboratoire de Physique Electronique des Solides (LPES), Centre de Recherches sur les Solides et leurs Applications (CRESA), EA 1174, Faculte des Sciences, Universite de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2 (France); Prevost, Hildegarde; Idri, Katia; Dusseau, Laurent [CEM2-CNRS UMR 5507, Universite de Montpellier II, Montpellier, Cedex 5 (France)

    2006-12-15

    The photoluminescence (PL), thermostimulated luminescence (TSL) and optical stimulated luminescence (OSL) properties of a cerium and samarium codoped strontium sulfide (SrS:Ce,Sm) used in OSL imaging devices are studied after UV or X-ray irradiation. A correlation is made between TSL and OSL results, showing a strong thermal and optical fading at room temperature, implying a significant instability of the OSL signal. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Synthesis and Electrical Conductivities of Sm2O3-CeO2 Systems

    Institute of Scientific and Technical Information of China (English)

    Song Xiwen; Peng Jun; Zhao Yongwang; Zhao Wenguang; An Shengli

    2005-01-01

    Doped Ceria nano-powders were synthesized via a Pechini-type gel rout. The specific surface area of Ce0.8Sm0.2O1.9 powder measured by the multilayer BET method is 41 m2.g-1. The electrical conductivities of Sm2O3-CeO2 systems were measured by the ac impedance technique in air at temperatures ranging from 513 to 900 ℃. Typical impedance spectra consist of two depressed semicircles at reduced measuring temperature and one depressed semicircle at elevated measuring temperature respectively, from which the grain interior and grain boundary conductivities were calculated. The relationship between the conductivities of Sm2O3 doped CeO2 (SDC) electrolyte and measuring temperature obeys Arrhenius equation. The grain interior conductivity of SDC varies slightly with improving sintering temperature, while the total conductivity increases with enhancing sintering temperature. The effective index has a significant effect on the ionic conductivity of ceria doped based electrolyte. When the effective index improves, the ionic conductivity increases and the apparent conductance activation energy decreases.

  17. Luminescence and scintillation properties of BaF2sbnd Ce transparent ceramic

    Science.gov (United States)

    Luo, Junming; Sahi, Sunil; Groza, Michael; Wang, Zhiqiang; Ma, Lun; Chen, Wei; Burger, Arnold; Kenarangui, Rasool; Sham, Tsun-Kong; Selim, Farida A.

    2016-08-01

    Cerium doped Barium Fluoride (BaF2sbnd Ce) transparent ceramic was fabricated and its luminescence and scintillation properties were studied. The photoluminescence shows the emission peaks at 310 nm and 323 nm and is related to the 5d-4f transitions in Ce3+ ion. Photo peak at 511 keV and 1274 keV were obtained with BaF2sbnd Ce transparent ceramic for Na-22 radioisotopes. Energy resolution of 13.5% at 662 keV is calculated for the BaF2sbnd Ce transparent ceramic. Light yield of 5100 photons/MeV was recorded for BaF2sbnd Ce(0.2%) ceramic and is comparable to its single crystal counterpart. Scintillation decay time measurements shows fast component of 58 ns and a relatively slow component of 434 ns under 662 keV gamma excitation. The slower component in BaF2sbnd Ce(0.2%) ceramic is about 200 ns faster than the STE emission in BaF2 host and is associated with the dipole-dipole energy transfer from the host matrix to Ce3+ luminescence center.

  18. Synthesis and characterization of Sm3+-doped CeO2 powders

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-cong; CHEN Li-miao; DUAN Xue-chen; LIANG Da-wen

    2008-01-01

    Sm3+-doped CeO2 (denoted as Ce1-xSmxO2) powders with different morphologies were successfully synthesized via a precursor-growth-calcination approach, in which precursor was first synthesized by a hydrothermal method and Ce1-xSmxO2 powders were finally obtained through a calcination process. The products were characterized with X-ray diffractometry(XRD), field emission scanning electron microscopy(FE-SEM) and fluorescence spectroscopy. The results reveal that the Ce1-xSmxO2 powders obtained by calcining the precursors prepared in the absence and presence of poly(vinyl pyrrolidone) (PVP) exhibit bundle- and sphere-like morphology, respectively. The possible growth process was proposed by preparing a series of intermediate morphologies during the shape evolution of CeO2 based on the SEM image observation. It is also found that the luminescence intensity of bundle-like Ce1-xSmxO2 is enhanced in comparison with that of sphere-like one due to its special morphology.

  19. Effects of Ti4+ Ions on Fluorescence Properties of Sr2CeO4:Sm3+ Phosphors.

    Science.gov (United States)

    Jiao, Haiyan; Wang, Peiyu; Liu, Liwei; Wang, Yuhua

    2016-04-01

    Ti4+-doped Sr2CeO4:Sm3+ phosphors were synthesized with the solid-state reaction method and the effects of doping Ti4+ on the photoluminescence properties were investigated in detail. A broad excitation band ascribed to the O2- -Ce4+ transition was observed in the range of 200 to 400 nm and with doping Ti4+ nto Ce4+ sites, the intensity of charge transfer band of O2- --> Ce4+ (300-370 nm) was significantly broaden and enhanced. As a result, the emission intensity of Sr2Ce1-xTixO4 has improved about 85% by doping 0.01 mol Ti4+. White emission of Sr2-yCe0.99Ti0.01O4:ySm3+ at y O2- CT emission and 4G5/2-6HJ Sm3+ transitions whereas only the Sm3+ red emission prevails for 0.03 phosphor exhibited excellent color purity. Its chromaticity coordinate is measured to be (0.326, 0.322), which is close to the pure white (0.33, 0.33). The results showed that Sr1.99Ce0.99Ti0.01O4: 0.01 Sm3+ phosphors could be considered as a potential single-phase white-emitting phosphor for white light-emitting diodes. PMID:27451755

  20. MgO:Li,Ce,Sm as a high-sensitivity material for Optically Stimulated Luminescence dosimetry

    Science.gov (United States)

    Oliveira, Luiz C.; Yukihara, Eduardo G.; Baffa, Oswaldo

    2016-04-01

    The goal of this work was to investigate the relevant dosimetric and luminescent properties of MgO:Li3%,Ce0.03%,Sm0.03%, a newly-developed, high sensitivity Optically Stimulated Luminescence (OSL) material of low effective atomic number (Zeff = 10.8) and potential interest for medical and personal dosimetry. We characterized the thermoluminescence (TL), OSL, radioluminescence (RL), and OSL emission spectrum of this new material and carried out a preliminary investigation on the OSL signal stability. MgO:Li,Ce,Sm has a main TL peak at ~180 °C (at a heating rate of 5 °C/s) associated with Ce3+ and Sm3+ emission. The results indicate that the infrared (870 nm) stimulated OSL from MgO:Li,Ce,Sm has suitable properties for dosimetry, including high sensitivity to ionizing radiation (20 times that of Al2O3:C, under the measurement conditions) and wide dynamic range (7 μGy–30 Gy). The OSL associated with Ce3+ emission is correlated with a dominant, practically isolated peak at 180 °C. Fading of ~15% was observed in the first hour, probably due to shallow traps, followed by subsequent fading of 6–7% over the next 35 days. These properties, together with the characteristically fast luminescence from Ce3+, make this material also a strong candidate for 2D OSL dose mapping.

  1. Improvement of critical current densities in SmBa2Cu3Oy, films with BaHfO3 nano-rods using low temperature growth technique

    International Nuclear Information System (INIS)

    We studied growth substrate temperature dependent morphologies of BaHfO3 (BHO) nano-rods for SmBa2Cu3Oy, (SmBCO) films with BHO fabricated by pulsed laser deposition (PLD) method. The morphology of BHO nano-rods within the SmBCO matrix could be controlled by changing substrate temperatures adoping a Low Temperature Growth (LTG) technique. Using the LTG technique, we could fabricate SmBCO films showed c-axis orientation even at low substrate temperature during deposition without a degradation of superconducting properties, which is one of the most advantages of the LTG technique. In this study, we found an optimal morphology of the BHO nano-rods and the morphology was fine, straight and various growth directions. The BHO nano-rods were more effective to improve the Jc in a magnetic field than other morphologies of the BHO nano-rods.

  2. Photoluminescence and thermally stimulated luminescence properties of CaSO{sub 4}:Sm{sup 3+} and CaSO{sub 4}:Ce{sup 3+},Sm{sup 3+}; Sm{sup 3+} {yields} Sm{sup 2+} conversion and high temperature dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Prevost, Hildegarde; Dusseau, Laurent [Institut d' Electronique du Sud (IES), UMR UM2-CNRS 5214, Universite de Montpellier II, Place Eugene Bataillon - CC 083, 34095 Montpellier Cedex 5 (France); Angellier, Gaelle; Mady, Franck; Benabdesselam, Mourad [Laboratoire de Physique Electronique des Solides (LPES), Centre de Recherches sur les Solides et leurs Applications (CRESA), EA 1174, Faculte des Sciences, Universite de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2 (France); Lapraz, Dominique

    2007-12-15

    The photoluminescence (PL) and thermally stimulated luminescence (TSL) properties of CaSO{sub 4}:Sm and CaSO{sub 4}:Ce,Sm are studied. After X irradiation of CaSO{sub 4}:Sm, an obvious Sm{sup 3+}/Sm{sup 2+} redox process is observed. The Ce co-doping is responsible for the presence of an intense TSL peak at about 485/500 C, showing an interesting application in high temperature radiation dosimetry. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Elastic and Piezoelectric Properties of Ce:BaTiO3 Single Crystals

    Institute of Scientific and Technical Information of China (English)

    DING Shuo; ZHU Yong; LIU Yu-Long; SIU G. G.; LEE C. M.; JIANG Yi-Jian

    2005-01-01

    @@ Laser Brillouin scattering is applied to measure the sound velocity and the sound anisotropic velocity in highquality single-domain tetragonal Ce:BaTiO3 single crystals at room temperature. The elastic and piezoelectric constants are thus determined. Based on the sound propagation equations and these results, the directional dependence of the compressional and shear modulus of Ce:BaTiO3 in the (010) and (001) planes are investigated.Some properties of sound propagation and electromechanical coupling in the crystal are discussed.

  4. Effects of Nd, Sm, Gd, Dy, Er Dopant on Electrical Properties of BaTiO3 Ceramics

    Institute of Scientific and Technical Information of China (English)

    Hao Sue; Wei Yongde; Xing Xiaoxu

    2004-01-01

    BaTiO3 ceramics doped with various quantities of Nd2O3, Sm2O3, Gd2O3, Dy2O3 and Er2O3 were prepared respectively ( the adulterate concentrations were 0. 001,0. 002, 0. 003, 0.005, 0. 007 mol fraction) through a sol-gel method and their electrical properties were researched. It is found that each adulteration of Nd2O3, Sm2O3 Gd2O3,Dy2O3 and Er2O3 all can make the resistivity of BaTiO3 ceramics decline , especially Sm2O3 and Gd2O3. When the addition of Sm2O3 is 0. 001 mol, the resistivity is the smallest, declining from 4.0 × 1012 to 6.5 × 103 Ω different kind of rare earth exhibits different regularity. The grain resistance of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 exhibits a NTC effect, at the same time the grain boundary resistance has a PTC effect, and the grain boundary resistance is much larger than the grain resistance, so the PTC effects of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 originate from the grain boundary. The additions of Nd2O3 , Gd2O3 or Er2O3 make the dielectric constant and the dielectric loss of BaTiO3 ceramics change evidently, especially Nd2O3. The dielectric constant is larger than that of pure BaTiO3 ceramics, on the other hand, the dielectric loss is much lower, which is useful in capacitor fields.

  5. Low-frequency dielectric spectroscopy of BaTiO3:Ce3+ ceramics

    Science.gov (United States)

    Berbecaru, Ciceron

    2015-10-01

    Dielectric spectroscopy of BaTiO3 (BT) doped with Ce3+ (BT:Ce3+) ceramics was performed at extended temperatures and in the low-frequency ranges. BT:Ce3+ displays decreasing values of all phase transition temperatures with increasing Ce3+ content. Permittivity versus temperature plots showed decreasing values with increasing frequency with low dispersion and shifting values of the Curie temperatures (Tc) towards high frequencies. Comparable values of losses for BT and BT:Ce3+ ceramics suggest good charge compensation. At low frequencies and higher temperatures, thermally activated mechanisms of conduction increase the loss values. With increasing frequency, the BT:Ce3+ system displays increased and shifted loss peaks up to Tc and decreasing values above Tc. The characteristic exponent of the modified Curie-Weiss law is higher than one. These figures suggest a relaxor-like behaviour of BT:Ce3+ ceramics for low Ce3+ content. Phase diagrams of BT:Ce3+ ceramics show a strong decrease of Tc for low Ce3+ content.

  6. Thermoelectric properties of molybdenum oxides LnMo(8)O(14) (Ln = La, Ce, Pr, Nd and Sm)

    DEFF Research Database (Denmark)

    Xu, Jianxiao Jackie; Sonne, Monica; Pryds, Nini;

    2010-01-01

    The series LnMo8O14 (Ln = La, Ce, Pr, Nd and Sm) containing bicapped Mo8 clusters was synthesized via solid state reaction at 1673 K. Oxides of this type were reported to be narrow gap semiconductors. Our Seebeck coefficient measurements show that some of these reduced molybdenum oxides exhibit...

  7. Structural and Dielectric Properties of Ba5RNiNb9O30(R=La, Nd and Sm) ceramics

    Institute of Scientific and Technical Information of China (English)

    XU Man; HU Changzheng; ZHANG Hui; WU Bolin

    2006-01-01

    Three novel Ba5RNiNb9O30 (R= La, Nd and Sm) ceramics were prepared and characterized in the BaO-R2O3-NiO-Nb2O5 system. All three compounds are paraelectric phases adopting the filled tetragonal tungsten bronze (TB) structure at room temperature. At 1MHz, Ba5RNiNb9O30 ceramics have a high dielectric constants in the range 193-245.3, a low dielectric loss in range 0.0059-0.0087, and the temperature coefficients of the dielectric constant (τε) in the range -1 140--1 310×10-6·℃-1.Their temperature coefficientsof the dielectric constant are significantly reduced compared to those of Ba 5RTi 3Ta 7O 30(R=La, Nd, Sm) ceramics.

  8. New oxocompounds with planar coordinated Pd2+ BaPdNd2O5 and BaPdSm2O5

    International Nuclear Information System (INIS)

    Single crystals of BaPdNd2O5(A), BaPdSm2O5(B) and BaCuNd2O5(C) were prepared by solid state reaction using BaCl2 as a fusing assistant (A, B) or by high temperature Laser technique (C). X-ray investigations show tetragonal symmetry with A: a=6.7387(5), c=5.9002(25)A, B: a=6.6667(13), c=5.8800(6)A (space group D4sub(4h) - P4/mbm, Z=2). The formerly investigated compound (C) is refined here by single crystal data. (A) and (B) belong to the BaPtNd2O5-type. The results are discussed. (Author)

  9. SmBa2NbO6 Nanopowders, an Effective Percolation Network Medium for YBCO Superconductors

    Directory of Open Access Journals (Sweden)

    S. Vidya

    2013-01-01

    Full Text Available The percolation behavior of superconductor-insulator composite, YBa2Cu3O7–δ, and nano SmBa2NbO2 synthesized by modified combustion technique was studied. Particle size of nano SmBa2NBO6 was determined using transmission electron microscopy. The chemical nonreactivity of nano SmBa2NbO6 with YBCO is evident from the X-Ray diffraction study which makes it a suitable nanoceramic substrate material for high temperature superconducting films. A systematic increase in the sintered density, approaching the optimum value of the insulating nanophase is clearly observed, as the vol.% of YBCO in the composite decreases. SEM micrograph showed uniform distribution of nanopowder among the large clusters of YBCO. The obtained percolation threshold is ~26 vol% of YBCO in the composite. All the composites below the threshold value showed TC(0~92 K even though the room resistivity increases with increase in vol.% of nano SmBa2NbO6. The values of critical exponents obtained matches well with the theoretically expected ones for an ideal superconductor-insulator system.

  10. Dielectric Properties of CeO2 -Doped Ba( Zr, Ti)O3 Ceramics

    Institute of Scientific and Technical Information of China (English)

    Huang Xinyou; Gao chunhua; Chen Xiangchong; Liu Huiping; Huang Guojun; Zheng Xialian

    2004-01-01

    The influence of additive amount of CeO2 on the properties of Ba(Ti, Zr)O3 (BTZ) capacitor ceramics prepared using conventional solid-state reaction method was investigated. The dielectric constant(ε) increases to a maximum when w( CeO2 ) is about 1.0% and then decreases again at higher doping concentration of CeO2. The dielectric constant gets a maximum while w ( CeO2 ) is about 1. 0%, and the dielectric loss is minimum while w ( CeO2 ) is0.5 %. CeO2 can decrease the curie temperature, widen the εr-T peak and decrease the absolute value of dielectric constant temperature coefficient. The influence mechanism of CeO2 additive on the properties of the BTZ ceramics was discussed. The results show that CeO2 additive influences the properties of BTZ ceramics by means of forming defect solid solution , shifting curie temperature peak effect, segregating in crystal boundary , and impeding grain growth.

  11. Study on Preparation and Electrical Properties of Ba1.03 Ce0.2O3-α Solid Electrolyte

    Institute of Scientific and Technical Information of China (English)

    仇立干; 马桂林; 闻荻江

    2004-01-01

    Ba1.03Ce0.8Eu0.2O3-α solid electrolyte with nonstoichiometric composition was prepared by high temperature solid-state reaction. Phase composition,surface and fracture morphologies of the specimen were characterized by using XRD and SEM,respectively. Ionic conduction was researched by gas concentration cell,the performance of hydrogen-air fuel cell was measured in the temperature range of 600~1000 ℃,and compared them with those of BaCe0.8Eu0.2O3-α and Ba0.98Ce0.8Eu0.2O3-α. The results indicate that Ba1.03Ce0.8Eu0.2O3-α is a single-phase perovskite-type orthorhombic system. It is a pure proton conductor in the temperature range of 600~1000 ℃ in hydrogen atmosphere,and its proton conduction is superior to that of BaCe0.8Eu0.2O3-α and Ba0.98Ce0.8Eu0.2O3-α. It is a mixed conductor of oxide ion and electron hole in oxygen atmosphere. At 1000 ℃,the performance of the fuel cell in which Ba1.03Ce0.8Eu0.2O3-α as electrolyte is higher than that of BaCe0.8Eu0.2O3-α or Ba0.98Ce0.8Eu0.2O3-α.

  12. Site selective spectroscopy in BaYF{sub 5}:RE{sup 3+} (RE = Eu, Sm) nano-glass–ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, J. del, E-mail: fjvargas@ull.edu.es [Dpto. Física, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Yanes, A.C. [Dpto. Física, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Abe, S.; Smet, P.F. [LumiLab, Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, 9000 Gent (Belgium); Center for Nano- and Biophotonics (NB Photonics), Ghent University (Belgium)

    2015-06-25

    Highlights: • We obtained sol–gel transparent nGCs with Eu{sup 3+}, Sm{sup 3+}-doped cubic BaYF{sub 5} nanocrystals. • Eu{sup 3+}-doped BaYF{sub 5} NCs were prepared by solvothermal method. • Their luminescent properties were studied and compared with the Eu{sup 3+}-doped nGCs. • Eu{sup 3+}/Sm{sup 3+} were used as probe ions in the nGCs to distinguish different environments. • The incorporation of a large fraction of RE ions into the BaYF{sub 5} NCs was confirmed. - Abstract: Trivalent rare-earth (RE = Eu, Sm) doped transparent nano-glass–ceramics comprising BaYF{sub 5} nanocrystals were successfully obtained by appropriate heat-treatment of the corresponding precursor sol–gel glasses. Their structural and spectroscopic properties were investigated and compared with those for Eu{sup 3+}-doped-BaYF{sub 5} nanocrystals prepared by a solvothermal method. X-ray Diffraction, Transmission Electron Microscopy and Energy Dispersive X-ray Spectroscopy measurements confirmed the distribution of BaYF{sub 5} nanocrystals in the glass matrix, presenting a cubic phase structure with space group Fm-3m. In order to achieve a further structural characterization, the luminescence properties of the Eu{sup 3+} and Sm{sup 3+} dopants were also used as sensitive probes. The reduction in the emission intensities of hypersensitive transitions {sup 5}D{sub 0} → {sup 7}F{sub 2} and {sup 4}G{sub 5/2} → {sup 6}H{sub 9/2} for Eu{sup 3+} and Sm{sup 3+} ions respectively, along with time-resolved measurements, confirm the distribution of a significant fraction of RE ions into the fluoride nanocrystal environment. These results suggest that BaYF{sub 5} nano-glass–ceramics doped with Eu{sup 3+} or Sm{sup 3+} can be considered as potential red-emitting phosphors for the development of white LEDs under near UV excitation.

  13. Luminescence of BaAl2O4:Mn2+,Ce3+ phosphor

    International Nuclear Information System (INIS)

    Powder samples of barium aluminate doped with Mn2+ and Ce3+ were prepared by solid-state reaction method and their photoluminescence and thermoluminescence properties were studied. Substitution of Ca/Sr in place of Ba resulted in enhanced emission from Ce3+ ions without changing the spectral profile. Cerium efficiently sensitized the manganese luminescence in barium aluminate. Photoluminescence and thermo luminescence observations have indicated the presence of Vk3+ defects in undoped barium aluminate. However, Barium aluminate (either undoped or doped with manganese) did not exhibit long afterglow

  14. Preparation and Characteristics of Optical Storage Material CaS:Ce3+, Sm3+

    Institute of Scientific and Technical Information of China (English)

    Lu Liping; Zhang Xiyan; Liu Quansheng; Mi Xiaoyun; Xiao Zhiyi

    2004-01-01

    CaS: Ce3+, Sm3 + optical storage material was prepared by wet-method under the reducing atmosphere. Influence of sintering atmosphere on luminescence intensity was studied to get the result that active-carbon reducing atmosphere is better. XRD analysis shows that CaS crystal structure was formed at 700 ℃. The excitation spectrum is in the range of 250 ~ 500 nm with peaks at 260.2, 353.4 and 461.2 nm, the fluorescence spectrum shows a broadband spectrum with peaks at 503, 568 and 604 nm and the emission spectrum of the sample stimulated by 980 nm laser also shows a broadband spectrum with peaks at 508,565 and 600 nm. The result of spectra analysis indicates that this material can absorb and "trap" incoming light energy from ultraviolet and visible light (Information write-in), and release that stored energy in the form of green luminescence (information read-out) upon stimulation from a longer IR wavelength. The optical storage physical mechanism was also discussed.

  15. Interlayer magnetotransport study in electron-doped Sm2-CeCuO4-

    Indian Academy of Sciences (India)

    Takasada Shibauchi; Tsuyoshi Kawakami; Yuhki Terao; Minoru Suzuki; Lia Krusin-Elbaum

    2006-01-01

    Vortex and pseudogap states in electron-doped Sm2-CeCuO4- ( ∼ 0.14) are investigated by the interlayer transport in magnetic fields up to 45 T. To extract intrinsic properties, we fabricated small 30 nm-high mesa structures, sufficiently thin to be free of the recently reported partial decomposition problems. On cooling, the -axis resistivity ρc of the mesa structures reveals a semiconductive upturn above c, followed by a sharp superconducting transition at 20 K. When the magnetic field is applied along the -axis, ρc() shows a parallel shift without significant broadening, as also observed in the hole-doped underdoped cuprates. Above the transition we observe negative magnetoresistance (MR), which can be attributed to the field suppression of the pseudogap, whose magnitude is as small as 38 K. Our results in the ∼ 0.14 samples closely correspond to the interlayer transport behavior in the `overdoped' regime of hole-doped Bi2Sr2CaCu2O8+.

  16. Raman Active Phonons in RCoO3 (R=La, Ce, Pr, Nd, Sm, Eu, Gd, and Dy) Perovskites

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-Ran; XU Da-Peng; SU Wen-Hui; DING Zhan-Hui; XUE Yan-Feng; SONG Geng-Xin

    2005-01-01

    @@ We examine RCoO3 (R=La, Ce, Pr, Nd, Sm, Eu, Gd, and Dy) perovskites prepared with the solid-state reaction method by Raman spectroscopy, and report the Raman active phonons in the RCoO3 perovskites crystallized in cubic symmetry for RCoO3 (R=La, Ce, Pr and Nd) and orthorhombic symmetry for RCoO3 (R=Sm, Eu, Gd,and Dy). It is found that the Raman spectra of RCoO3 perovskites are strongly dependent on the ionic radius.of the rare earth elements, and the frequency shift of the most intense modes of the orthorhombic samples are correlated with some structural parameters such as Co-O bond distances, ionic radius of the rare earth elements and Jahn-Teller distortion. It is clear that Raman spectroscopy has the advantage of sensitivity to structure distortion and oxygen motion.

  17. Stress effect on Raman spectra of Ce-doped BaTiO3 films

    Science.gov (United States)

    Chen, M. S.; Shen, Z. X.; Tang, S. H.; Shi, W. S.; Cui, D. F.; Chen, Z. H.

    2000-08-01

    Ce-doped BaTiO3 (BTO:Ce) thin films prepared on MgO (100) substrates by pulsed laser deposition (PLD) at oxygen pressure of 1.2×10-3 and 17 Pa have been studied by micro-Raman spectroscopy, x-ray diffraction (XRD) and atomic force microscopy (AFM). The film deposited at lower oxygen pressure has a larger lattice parameter in the direction normal to the substrate surface, and the film has smaller grains and a smoother surface. The polarized Raman peaks of both as-deposited films show blue shifts and linewidth broadening in comparison to those of the BaTiO3 single crystal. The blue shifts are attributed to tensile stresses in the films. Our results indicate that the grain size increases and the tensile stress relaxes with annealing. We have shown that quantum confinement and oxygen vacancies are not the dominant factors for the observed Raman spectral changes.

  18. Fabrication and magnetic property of BaSm(x)Fe(12-x)O19 (x < or = 0.4) nanofibers.

    Science.gov (United States)

    Xian-Feng, Meng; Li-Ju, Guo

    2012-03-01

    BaSm(x)Fe(12-x)O19 (x saturation magnetization of BaSm(x)Fe(12-x)O19 ferrite nanofiber calcined at 950 degrees C for 1 h initially decreases with the Sm content from 0 to 0.3 and then increases with a further Sm content, while the coercivity exhibits a continuous increase from 348 kA x m(-1) (x = 0) to 427 kA x m(-1) (x = 0.4). The differences of magnetic properties are attributed to lattice distortion and enhancement for the anisotropy energy. PMID:22755131

  19. Comparative performances of LaBr3(Ce) and BaF2 scintillators

    International Nuclear Information System (INIS)

    Inorganic scintillation detectors have wide applications in nuclear spectroscopy, medical imaging, space science, geological exploration etc. The detectors that are recently attracted to the nuclear and particle physics experimentalists are La-halide, Lu2SiO5 (LSO) and BaF2 because of their superior energy and time resolutions. A BaF2 detector is known to have very good timing properties because of its ultrafast decay time component (600 ps) but a poor energy resolution (∼10% at 662 keV). On the other hand, La-halide detectors have subnanosecond time resolutions as well as excellent energy resolution because of their high light output and faster scintillation decay time (16 ns). Here, we have performed comparative studies of LaBr3(Ce) and BaF2 detectors with same crystal sizes (38 x 25 mm2)

  20. Heavy elements Ba, La, Ce, Nd, and Eu in 56 Galactic bulge red giants

    CERN Document Server

    Van der Swaelmen, M; Hill, V; Zoccali, M; Minniti, D; Ortolani, S; Gomez, A

    2016-01-01

    Aims. The aim of this work is the study of abundances of the heavy elements Ba, La, Ce, Nd, and Eu in 56 bulge giants (red giant branch and red clump) with metallicities ranging from -1.3 dex to 0.5 dex. Methods. We obtained high-resolution spectra of our giant stars using the FLAMES-UVES spectrograph on the Very Large Telescope. We inspected four bulge fields along the minor axis. Results. We measure the chemical evolution of heavy elements, as a function of metallicity, in the Galactic bulge. Conclusions. The [Ba, La, Ce, Nd/Fe] vs. [Fe/H] ratios decrease with increasing metallicity, in which aspect they differ from disc stars. In our metal-poor bulge stars, La and Ba are enhanced relative to their thick disc counterpart, while in our metal-rich bulge stars La and Ba are underabundant relative to their disc counterpart. Therefore, this contrast between bulge and discs trends indicates that bulge and (solar neighbourhood) thick disc stars could behave differently. An increase in [La, Nd/Eu] with increasing m...

  1. Sputter deposition of Ce(Sm,Y)O2 thin films: linking phase instability to grain size

    Science.gov (United States)

    Van Steenberge, S.; Depla, D.

    2016-06-01

    (1  ‑  x)CeO2  ‑  xMO1.5 thin films (with M  =  Y or Sm) were deposited using DC reactive dual magnetron sputtering. The influence of the substitution of Ce4+ ions by M3+ ions in the ceria fluorite structure is investigated with x-ray diffraction and scanning electron microscopy to provide a description of the thin film microstructural and textural evolution at room temperature and at elevated temperatures. Phase analysis shows that the fluorite structure can be maintained until a composition of x  =  0.40 of Y or Sm. At higher values of x, a diphasic region is observed. The films are thermally stable because no restructuring occurs when they are heated. A decrease in grain size is observed before the diphasic region forms which is typically explained from a reduced adatom mobility. However, the microstructure throughout the composition range is indicative of zone T growth. These findings illustrate that while the growth of a thin film is a kinetically driven process, the observed decrease in grain size is no evidence of a reduced surface adatom mobility but of imposed thermodynamic barriers. The critical composition for the grain size change coincides not only for both material systems (M  =  Y or Sm), but also with reported values of crystallographic structural changes in bulk material.

  2. Influences of Zr, Ce and Ba fission products on the surface properties of UO2: Atomistic simulations

    Science.gov (United States)

    Xiao, Hongxing; Long, Chongsheng; Tian, Xiaofeng; Chen, Hongsheng

    2016-07-01

    Molecular dynamics (MD) simulations with a shell-core model have been carried out to investigate the influences of Zr, Ce and Ba fission products on the surface properties of UO2. Simulation results indicate that (i) the presence of these fission products will change the surface energy of three low-index surfaces in UO2; (ii) the individual addition of Ce has no significant effect on the surface energy, while the individual addition of Ba will dramatically decrease the surface energy of UO2 by approximately 18% on (100) surface, 7% on (110) surface and 9% on (111) surface with the Ba contents ranging from 0 to 12.5 mol% at 300 K, which is obviously contrary to the Zr; (iii) the combined additions of Zr, Ce and Ba fission products will continuously increase the surface energy of UO2 (100), (110) and (111) surfaces; (iv) the structures of the three low-index surfaces in pure UO2 as well as U0.8(Zr, Ce, Ba)0.2O2 are dramatically disturbed after the free relaxation; (v) The nearest O atoms move towards the Zr and Ce atoms center by about 0.21 Å and 0.12 Å but move away from the Ba atom center by about 0.27 Å.

  3. Structural and 121Sb M\\"ossbauer Spectroscopic Investigations of the Antimonide Oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr)

    OpenAIRE

    Schellenberg, Inga; Nilges, Tom; Pöttgen, Rainer

    2008-01-01

    The quaternary antimonide oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr) were synthesized from the RESb monoantimonides and MnO, respectively ZnO. We report on single crystal X-ray data and a detailed 121Sb M\\"ossbauer spectroscopic investigation.

  4. Spectroscopic characteristics of Olgite (Ba,Sr)(Na,Sr){sub 2}Na[PO{sub 4}]{sub 2} crystals doped with Sm{sup 2+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Huang Yanlin [School of Material Engineering, Soochow University, 178 GanJiang East Road, Suzhou 215021 (China)], E-mail: huangyanlin@hotmail.com; Kai Weifang [School of Material Engineering, Soochow University, 178 GanJiang East Road, Suzhou 215021 (China); Lee, Ho Sueb; Cho, Eunjin [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jang, Kiwan [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of)], E-mail: kwjang@changwon.ac.kr; Cao Yonggang; Zhao Wanxue; Ding Haiyan; Wang Xigang [School of Material Engineering, Soochow University, 178 GanJiang East Road, Suzhou 215021 (China)

    2008-10-15

    Sm{sup 3+} ions doped Olgite crystals (Ba,Sr)(Na,Sr){sub 2}Na[PO{sub 4}]{sub 2} were prepared by high temperature solid-state reaction. Sm{sup 2+} ions were obtained by X-ray irradiation reduction. The samples were investigated by X-ray diffraction, SEM, photoluminescence and decay curves measurements. In (Ba,Sr)(Na,Sr){sub 2}Na[PO{sub 4}]{sub 2}, the influence of different mole ratios of Sr to Ba atoms on the crystal structure, reducing efficiencies of Sm{sup 3+} to Sm{sup 2+} and luminescence properties of Sm{sup 2+} ions were discussed. It is found that the conversion of Sm{sup 3+} {yields} Sm{sup 2+} after X-ray irradiation is efficient in this phosphate. The emission of Sm{sup 2+} in this host after excitation into the 4f{sup 5} 5d{sup 1} levels shows {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 0, 1, 2) emission together with a broad emission band. The characteristic of Sm{sup 2+} ions luminescence was discussed.

  5. Spectroscopic characteristics of Olgite (Ba,Sr)(Na,Sr)2Na[PO4]2 crystals doped with Sm2+ ions

    International Nuclear Information System (INIS)

    Sm3+ ions doped Olgite crystals (Ba,Sr)(Na,Sr)2Na[PO4]2 were prepared by high temperature solid-state reaction. Sm2+ ions were obtained by X-ray irradiation reduction. The samples were investigated by X-ray diffraction, SEM, photoluminescence and decay curves measurements. In (Ba,Sr)(Na,Sr)2Na[PO4]2, the influence of different mole ratios of Sr to Ba atoms on the crystal structure, reducing efficiencies of Sm3+ to Sm2+ and luminescence properties of Sm2+ ions were discussed. It is found that the conversion of Sm3+ → Sm2+ after X-ray irradiation is efficient in this phosphate. The emission of Sm2+ in this host after excitation into the 4f5 5d1 levels shows 5D0 → 7FJ (J = 0, 1, 2) emission together with a broad emission band. The characteristic of Sm2+ ions luminescence was discussed

  6. Sorption of Fe3+ , Co2+ , Ce3+ , Cs+ and Ba2+ in zeolite X

    International Nuclear Information System (INIS)

    The sorption behavior of Fe3+ , Co2+ , Ce3+ , Cs+ , and Ba2+ in aqueous solutions, was studied in presence of zeolite X. Solutions of Fe(NO3)3 . 9 H2 O, Co(NO3)2 . 6 H2 O, Ce(NO3)3 . 6 H2 O, Cs NO3 and Ba(NO3)2 were labelled with the respectively radioactive isotopes Fe59 , Co60, Cs134, Ba139 and Ce141. 20 ml. of each solution was left in contact with 200 mg. of zeolite for different periods. Later the zeolites were separated by centrifugation from the aqueous solutions and the radioactivity of the aqueous phases was measured with a NaI(Tl) solid-state well detector coupled to a single-channel Picker analyzer or with a Gel hyper pure solid-state detector coupled to a 2048 channel pulse height analyzer. When Cs+ in the aqueous solutions was left in contact with zeolite X it was found that it does not occupy all cationic sites in the zeolite due to the ionic radium effect. A similar behavior was found for the divalent ions. In all cases, when the pH was not controlled, the zeolite lost part of its crystallinity and when the divalent ions were exchanged again by Na+, the zeolite recovered completely its crystallinity. During the sorption, the ionic radius, and the charge are important parameters as well as the pH. When the pH of the solution was adjusted between 6.5 - 7.0 the crystallinity was maintained in some cases. For Fe3+ the crystallinity after the ion exchange was 94 % and when the pH was not adjusted the crystallinity was completely lost. It was found as well that the zeolite X induces the formation of H3 O+ which competes with the cations for the sites in the zeolite. (Author)

  7. Redox properties and VOC oxidation activity of Cu catalysts supported on Ce{sub 1−x}Sm{sub x}O{sub δ} mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Konsolakis, Michalis, E-mail: mkonsol@science.tuc.gr [Laboratory of Physical Chemistry and Chemical Processes, Department of Sciences, Technical University of Crete, University Campus, 73100 Chania (Greece); Carabineiro, Sónia A.C., E-mail: scarabin@fe.up.pt [Laboratório de Catálise e Materiais (LCM), Laboratório Associado LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, 4200-465 Porto (Portugal); Tavares, Pedro B. [CQVR, Centro de Química – Vila Real, Departamento de Química, Universidade de Trás-os-Montes e Alto Douro, 5001-911 Vila Real (Portugal); Figueiredo, José L. [Laboratório de Catálise e Materiais (LCM), Laboratório Associado LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, 4200-465 Porto (Portugal)

    2013-10-15

    Highlights: • Complete elimination of ethyl acetate is achieved at 260 °C with Cu/CeO{sub 2} catalysts. • Samarium has a detrimental impact on VOC oxidation, proportional to its content. • Incorporation of Sm in ceria has a detrimental effect on textural characteristics and reducibility. • Increase of Sm/Ce ratio results in a more reduced Cu species, inactive for VOC oxidation. • A correlation between VOC activity and catalysts redox properties is established. -- Abstract: A series of Cu catalysts supported on Ce{sub 1−x}Sm{sub x}O{sub δ} mixed oxides with different molar contents (x = 0, 0.25, 0.5, 0.75 and 1), was prepared by wet impregnation and evaluated for volatile organic compounds (VOC) abatement, employing ethyl acetate as model molecule. An extensive characterization study was undertaken in order to correlate the morphological, structural and surface properties of catalysts with their oxidation activity. The optimum performance was obtained with Cu/CeO{sub 2} catalyst, which offers complete conversion of ethyl acetate into CO{sub 2} at temperatures as low as 260 °C. The catalytic performance of Cu/Ce{sub 1−x}Sm{sub x}O{sub δ} was interpreted on the basis of characterization studies, showing that incorporation of samarium in ceria has a detrimental effect on the textural characteristics and reducibility of catalysts. Moreover, high Sm/Ce atomic ratios (from 1 to 3) resulted in a more reduced copper species, compared to CeO{sub 2}-rich supports, suggesting the inability of these species to take part in the redox mechanism of VOC abatement. Sm/Ce surface atomic ratios are always much higher than the nominal ratios indicating an impoverishment of catalyst surface in cerium oxide, which is detrimental for VOC activity.

  8. Fabrication of novel electrolyte-layer free fuel cell with semi-ionic conductor (Ba0.5Sr0.5Co0.8Fe0.2O3-δ- Sm0.2Ce0.8O1.9) and Schottky barrier

    Science.gov (United States)

    Afzal, Muhammad; Saleemi, Mohsin; Wang, Baoyuan; Xia, Chen; Zhang, Wei; He, Yunjuan; Jayasuriya, Jeevan; Zhu, Bin

    2016-10-01

    Perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) is synthesized via a chemical co-precipitation technique for a low temperature solid oxide fuel cell (LTSOFC) (300-600 °C) and electrolyte-layer free fuel cell (EFFC) in a comprehensive study. The EFFC with a homogeneous mixture of samarium doped ceria (SDC): BSCF (60%:40% by weight) which is rather similar to the cathode (SDC: BSCF in 50%:50% by weight) used for a three layer SOFC demonstrates peak power densities up to 655 mW/cm2, while a three layer (anode/electrolyte/cathode) SOFC has reached only 425 mW/cm2 at 550 °C. Chemical phase, crystal structure and morphology of the as-prepared sample are characterized by X-ray diffraction and field emission scanning electron microscopy coupled with energy dispersive spectroscopy. The electrochemical performances of 3-layer SOFC and EFFC are studied by electrochemical impedance spectroscopy (EIS). As-prepared BSCF has exhibited a maximum conductivity above 300 S/cm at 550 °C. High performance of the EFFC device corresponds to a balanced combination between ionic and electronic (holes) conduction characteristic. The Schottky barrier prevents the EFFC from the electronic short circuiting problem which also enhances power output. The results provide a new way to produce highly effective cathode materials for LTSOFC and semiconductor designs for EFFC functions using a semiconducting-ionic material.

  9. High power density cell using nanostructured Sr-doped SmCoO3 and Sm-doped CeO2 composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Suzuki, Toshio; Sumi, Hirofumi; Hamamoto, Koichi; Fujishiro, Yoshinobu

    2016-01-01

    High power density solid oxide electrochemical cells were developed using nanostructure-controlled composite powder consisting of Sr-doped SmCoO3 (SSC) and Sm-doped CeO2 (SDC) for electrode material. The SSC-SDC nano-composite powder, which was synthesized by spray pyrolysis, had a narrow particle size distribution (D10, D50, and D90 of 0.59, 0.71, and 0.94 μm, respectively), and individual particles were spherical, composing of nano-size SSC and SDC fragments (approximately 10-15 nm). The application of the powder to a cathode for an anode-supported solid oxide fuel cell (SOFC) realized extremely fine cathode microstructure and excellent cell performance. The anode-supported SOFC with the SSC-SDC cathode achieved maximum power density of 3.65, 2.44, 1.43, and 0.76 W cm-2 at 800, 750, 700, and 650 °C, respectively, using humidified H2 as fuel and air as oxidant. This result could be explained by the extended electrochemically active region in the cathode induced by controlling the structure of the starting powder at the nano-order level.

  10. A high temperature neutron diffraction study of the double perovskite Ba{sub 2}{sup 154}SmMoO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Thomas K. [Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE (United Kingdom); Ritter, Clemens [Institut Laue Langevin, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble Cedex 9 (France); Mclaughlin, Abbie C., E-mail: a.c.mclaughlin@abdn.ac.uk [Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE (United Kingdom)

    2012-12-15

    Ba{sub 2}LnMoO{sub 6} double perovskites have been recently shown to display a wide range of interesting magnetic and structural properties; Ba{sub 2}{sup 154}SmMoO{sub 6} exhibits simultaneous antiferromagnetic order and a Jahn-Teller distortion. Here we report a high temperature neutron diffraction study of Ba{sub 2}{sup 154}SmMoO{sub 6} from 353 to 877 K. The results evidence a tetragonal to cubic phase transition at 423 K. Above this temperature the thermal displacement parameters of the oxygen atoms are modelled anisotropically as a result of a transverse vibration of the bridging oxygen. A smooth increase in the cell parameter a is observed with temperature for Ba{sub 2}{sup 154}SmMoO{sub 6}. - Graphical abstract: The high temperature crystal structure of Ba{sub 2}{sup 154}SmMoO{sub 6} evidencing a transverse oxygen vibration. Highlights: Black-Right-Pointing-Pointer A high temperature neutron diffraction study has been performed on an isotopically enriched sample of Ba{sub 2}{sup 154}SmMoO{sub 6}. Black-Right-Pointing-Pointer A cubic-tetragonal phase transition occurs below 423 K. Black-Right-Pointing-Pointer The thermal displacement parameters of the bridging oxygens are modelled anisotropically. Black-Right-Pointing-Pointer There is a transverse vibration of the bridging oxygen.

  11. Mixed Conduction in BaCe08Pr0.2O3- α Ceramic

    Institute of Scientific and Technical Information of China (English)

    Mao-yuan Wang; Li-gan Qiu

    2008-01-01

    BaCe0.8Pr0.2O3-α ceramic was synthesized by high temperature solid-state reaction. The structural char- acteristics and the phase purity of the crystal were determined using powder X-ray diffraction analysis. By using the methods of AC impedance spectroscopy, gas concentration cell and electrochemical pumping of hydrogen, the conductivity and ionic transport number of BaCe0.8Pr0.2O3-α were measured, and the elec- trical conduction behavior of the material was investigated in different gases in the temperature range of 500-900 ℃. The results indicate that the material was of a single perovskite-type orthorhombic phase. Prom 500 ℃ to 900 ℃, electronic-hole conduction was dominant in dry and wet oxygen, air or nitrogen, and the total conductivity of the material increased slightly with increasing oxygen partial pressure in the oxygen partial pressure range studied. Ionic conduction was dominant in wet hydrogen, and the total conductivity was about one or two orders of magnitude higher than that in hydrogen-free atmosphere (oxygen, air or nitrogen).

  12. Ionic Conduction in Ba0.95Ce0.8Ho0.2O3-α

    Institute of Scientific and Technical Information of China (English)

    WANG,Mao-Yuan; QIU,Li-Gan; MA,Gui-Lin

    2007-01-01

    Ba0.95Ce0.8Ho0.2O3-α was prepared by high temperature solid-state reaction. X-ray diffraction (XRD) pattern showed that the material was of a single perovskite-type orthorhombic phase. Using the material as solid electrolyte and porous platinum as electrodes, the measurements of ionic transport number and conductivity of Ba0.95Ce0.8Ho0.2O3-α were performed by gas concentration cell and ac impedance spectroscopy methods in the temperature range of 600-1000 ℃ in wet hydrogen, dry and wet air respectively. Ionic conduction of the material was investigated and compared with that of BaCe0.8Ho0.2O3-α. The results indicated that Ba0.95Ce0.8Ho0.2O3-α was a pure protonic conductor with the protonic transport number of 1 during 600-700 ℃ in wet hydrogen, a mixed conductor of protons and electrons with the protonic transport number of 0.97-0.93 in 800-1000 ℃. But BaCe0.8Ho0.2O3-α was almost a pure protonic conductor with the protonic transport number of 1 in 600-900 ℃ and 0.99 at 1000 ℃ in wet hydrogen. In dry air and in the temperature range of 600-1000 ℃, they were both mixed conductors of oxide ions and electronic holes, and the oxide-ionic transport numbers were 0.24-0.33 and 0.17-0.30 respectively. In wet air and in the temperature range of 600-1000 ℃, they were both mixed conductors of protons, oxide ions and electronic holes, the protonic transport numbers were 0.11-0.00 and 0.09-0.01 respectively, and the oxide-ionic transport numbers were 0.41-0.33 and 0.27-0.30 respectively. Protonic conductivity of Ba0.95Ce0.8Ho0.2O3-α in both wet hydrogen and wet air was higher than that of BaCe0.8Ho0.2O3-α in 600-800 ℃, but lower in 900-1000 ℃. Oxide-ionic conductivity of the material was higher than that of BaCe0.8Ho0.2O3-α in both dry air and wet air in 600-1000 ℃.

  13. Structural, dielectric and electrical properties of CaBa4SmTi3Nb7O30 ferroelectric ceramic

    Indian Academy of Sciences (India)

    Prasun Ganguly; A K Jha

    2011-07-01

    The polycrystalline sample of CaBa4SmTi3Nb7O30, a member of tungsten bronze family, was prepared by solid-state reaction method. X-ray diffraction analysis shows the formation of single-phase compound with an orthorhombic structure at room temperature. Scanning electron micrograph of the material shows uniform distribution of grains. Detailed studies of dielectric properties of the compound as a function of temperature at different frequencies suggest that the compound has a dielectric anomaly of ferroelectric to paraelectric type at 198°C, and exhibits non-relaxor kind of diffuse phase transition. The ferroelectric nature of the compound has been confirmed by recording polarization–electric field hysteresis loop. Piezoelectric and pyroelectric studies of the compound have been discussed in this paper. Electrical properties of the material have been analyzed using complex impedance technique. The Nyquist plots manifest the contribution of grain boundaries (at higher temperature), in addition to granular contribution (at all temperatures) to the overall impedance. The temperature dependence of dc conductivity suggests that the compound has negative temperature coefficient of resistance (NTCR) behaviour. The frequency dependence of ac conductivity is found to obey Jonscher’s universal power law. The observed properties have been compared with calcium free Ba5SmTi3Nb7O30 compound.

  14. Structure and fluorescent properties of Ba3Sc(PO4)3:Sm3+ red-orange phosphor for n-UV w-LEDs

    Science.gov (United States)

    Ma, Xiaoxue; Mei, Lefu; Liu, Haikun; Liao, Libing; Liu, Yuqin; Nie, Kun; Li, Zhaohui

    2016-06-01

    An appropriate solid-state route was adopted to synthesize a series of related Ba3Sc(PO4)3:xSm3+ red-orange phosphors. The Rietveld method was used to explore the structure of the phosphor. At present the PL, PLE, diffuse reflection and decay curves have been investigated in detail. These phosphors can be accurately excited by the 406 nm n-UV light and produce the emitted red-orange light whose peaks locate at about 566 nm, 603 nm and 650 nm. The quantum efficiency of Ba3Sc0.95(PO4)3:0.05Sm3+ was 53.5%. All above results indicate that Ba3Sc(PO4)3:Sm3+ phosphor can act as a suitable candidate of the warm components of n-UV w-LEDs.

  15. Ba2Mg(BO3)2:Ce3+,Eu2+,Na+: A potential single-phased two colour borate phosphor for white light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    PAN Zaifa; XU Juan; ZHU Chengjing; LIU Wenhan; WANG Lili

    2012-01-01

    A two colour phosphor Ba2Mg(BO3)2:Ce3+,Eu2+,Na+ was synthesized using solid-state reaction method.Luminescence of Ba2Mg(BO3)2:Ce3+,Eu2+,Na+ showed 416 and 618 nm emission bands attributed to Ce3+ and Eu2+ emission,respectively.Energy transfer occurred from Ce3+ to Eu2+ through a significant overlap of Eu2+ excitation spectrum with Ce3+ emission spectrum in Ba2Mg(BO3)2.They also showed that under the excitation of UV radiation,bluish or yellowish white light was generated by coupling a broad blue emission band and a red emission band.By combining with green phosphor,Ba2Mg(BO3):Ce3+,Eu2+,Na+ phosphor showed potential application for white light-emitting diodes (LEDs).

  16. Structure and magnetic properties of Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H-polytype in the Ba-Ce-Mn-O system

    Energy Technology Data Exchange (ETDEWEB)

    Macias, Mario A. [Grupo de Investigacion en Quimica Estructural (GIQUE), Universidad Industrial de Santander, A.A. 678, Carrera 27, Calle 9, Ciudad Universitaria, Bucaramanga (Colombia); Mentre, Olivier [Universite Lille Nord de France, Unite de Catalyse et de Chimie du Solide, Equipe Chimie du Solide, Avenue Dimitri Mendeleieev, Batiment C7, ENSCL/UST Lille 1, BP 90108, 59652 Villeneuve d' Ascq Cedex (France); Colis, Silviu [Institut de Physique et Chimie des Materiaux de Strasbourg (IPCMS), UMR 7504 UDS-CNRS (UDS-ECPM), 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2 (France); Cuello, Gabriel J. [Institut Laue Langevin, 6 rue Jules Horowitz BP 156, F-38042 Grenoble cedex 9 (France); Gauthier, Gilles H., E-mail: gilgau@uis.edu.co [Grupo de Investigacion en Quimica Estructural (GIQUE), Universidad Industrial de Santander, A.A. 678, Carrera 27, Calle 9, Ciudad Universitaria, Bucaramanga (Colombia); CEA, LITEN, Laboratoire d' Innovation Technologique et des Energies Nouvelles, 17 rue des Martyrs, 38054 Grenoble (France)

    2013-02-15

    Based on the peculiar magnetic properties that are observed in pseudo one-dimensional manganites, we decided to synthesize the new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} compound. The preparation was performed by solid state reaction in air at about 1350 Degree-Sign C, for which we found that the compound crystallizes in a hexagonal symmetry with space group P6{sub 3}/mmc (No-194) and cell parameters a=b=5.7861(2) A and c=23.902(1) A. The structural description was correlated with neutron diffraction and bond valence calculations, confirming the presence of Ce{sup 4+} and Mn{sup 4+} segregated in the different crystallographic positions. Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} displays evidence for strong AFM couplings already set at room temperature. The main arrangement of Mn{sup 4+} in magnetically isolated tetramers of face-sharing octahedra is responsible for a metamagnetic-like transition around 50 K. - Graphical abstract: The new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} polytype shows strong AFM couplings in magnetically isolated [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers of face-sharing octahedral, resulting in a metamagnetic-like transition around 50 K. Highlights: Black-Right-Pointing-Pointer Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H polytype, has been prepared in the Ba-Ce-Mn-O system. Black-Right-Pointing-Pointer The compound crystallizes in the P6{sub 3}/mmc space group with (cchhh){sub 2} stacking sequence. Black-Right-Pointing-Pointer [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers are separated by [CeO{sub 6}] octahedra in the structure. Black-Right-Pointing-Pointer Instead of robust AFM ordering, a metamagnetic-like transition is found around 50 K.

  17. Calibration of LiBaF sub 3 Ce scintillator for fission spectrum neutrons

    CERN Document Server

    Reeder, P L

    2002-01-01

    The scintillator LiBaF sub 3 doped with small amounts of Ce sup + sup 3 has the ability to distinguish heavy charged particles (p, d, t, or alpha) from beta and/or gamma radiation based on the presence or absence of nanosecond components in the scintillation light output. Since the neutron capture reaction on sup 6 Li produces recoil alphas and tritons, this scintillator also discriminates between neutron induced events and beta or gamma interactions. An experimental technique using a time-tagged sup 2 sup 5 sup 2 Cf source has been used to measure the efficiency of this scintillator for neutron capture, the calibration of neutron capture pulse height, and the pulse height resolution--all as a function of incident neutron energy.

  18. Phase conjugator with two coherent beams in a BaTiO3: Ce crystal

    Institute of Scientific and Technical Information of China (English)

    武建劳; 谢平; 戴建华; 张洪钧

    2000-01-01

    A phase conjugator which includes two coherent beams that are incident upon one of a-faces of a BaTiO3: Ce crystal without internal reflection is performed experimentally. Based on the four-wave mixing, the mechanism of this conjugator is investigated numerically. in comparison with the cor-responding self-pumped phase conjugator, the phase-conjugate behavior of this conjugator is estab-lished much more quickly, its phase conjugate reflectivity is greater in some cases and the intensity threshold is lower by over two orders of magnitude. The configuration of this conjugator is easy to per-form because the output response exists over a wide range of angular and lateral positions of the two incident beams on the crystal.

  19. Synthesis and thermochemistry of new phase BaCe0.7Nd0.2In0.1O2.85

    International Nuclear Information System (INIS)

    Highlights: •We synthesized new phase BaCe0.7Nd0.2In0.1O2.85. •We measured formation enthalpy of BaCe0.7Nd0.2In0.1O2.85. •The phase is thermodynamically stable with respect to decomposition into binary oxides. -- Abstract: The BaCe0.7Nd0.2In0.1O2.85 phase has been prepared from BaCO3, CeO2, Nd2O3 and In2O3. X-ray measurements have showed that BaCe0.7Nd0.2In0.1O2.85 has an orthorhombic structure (Pmcn space group). The standard formation enthalpy of BaCe0.7Nd0.2In0.1O2.85 has been determined by solution calorimetry combining solution enthalpies of BaCe0.7Nd0.2In0.1O2.85, BaCl2 + 0.7CeCl3 + 0.2NdCl3 + 0.1InCl3 mixture in 1 M HCl with KI and literature data. We determined the thermodynamic stability of Nd(In)-doped barium cerate with respect to mixtures of binary oxides. On the basis of the data we established that above-mentioned mixed oxide is thermodynamically stable with respect to their decomposition into binary oxides at room temperatures. We also established that BaCe0.7Nd0.2In0.1O2.85 is thermodynamically favored than BaCe0.8Nd0.2O2.9

  20. Ionic conduction in Ba_xCe_(0.8)Pr_(0.2)O_(3-α)

    Institute of Scientific and Technical Information of China (English)

    WANG Maoyuan; QIU Ligan; SUN Yufeng

    2009-01-01

    Ba_xCe_(0.8)Pr_(0.2)O_(3-α)(X=0.98-1.03) ceramics were prepared by high temperature solid-state reaction. X-ray diffraction (XRD) patterns showed that the materials were perovskite-type orthorhombic single phase. By using gas concentration cell and AC impedance spectroscopy methods, the electrical conduction behavior of the materials was investigated in different gases at 500-900 ℃. The influence of non-stoichiometry in the materials with x≠1 on conduction properties was studied and compared with that in the material with x=1. The results indicated that Ba_(1.03)Ce_(0.8)Pr_(0.2)O_(3-α) was a pure protonic conductor, and Ba_(0.98)Ce_(0.8)Pr_(0.2)O_(3-α) was a mixed conductor of protons and electrons in wet hydrogen at 500-900 ℃. BaCe_(0.8)Pr_(0.2)O_(3-α) was a pure protonic conductor in 500-600 ℃, and a mixed conductor of protons and electrons above 600℃ in wet hydrogen. In 500-900℃, they were all mixed conductors of oxide ions and electronic holes in dry air, and mixed con-ductors of protons, oxide ions and electronic holes in wet air. Both the protonic and oxide ionic conductivities increased with increasing bar-ium content in the materials in wet hydrogen, dry air and wet air, respectively.

  1. Effects of NiO on the conductivity of Ce0.85Sm0.15O1.925 and on electrochemical properties of the cathode/electrolyte interface

    Science.gov (United States)

    Wang, Haopeng; Liu, Xiaomei; Bi, Hailin; Yu, Shenglong; Han, Fei; Sun, Jialing; Zhu, Lili; Yu, Huamin; Pei, Li

    2016-07-01

    Ce0.85Sm0.15O1.925 (SDC) and Ce0.85Sm0.15O1.925-0.5 at.% NiO (SDCN) are investigated as electrolytes for solid oxide fuel cells (SOFCs). Impedance spectroscopy measurements reveal that the grain boundary resistance can be significantly reduced by adding 0.5 at.% NiO to SDC. Symmetric cells of the BaCo0.7Fe0.2Nb0.1O3-δ (BCFN) electrode on SDC and SDCN electrolytes are fabricated and the electrochemical properties of the electrode/electrolyte interface are investigated. The polarization resistance of the BCFN electrode on the SDCN electrolyte is much lower than that of the BCFN electrode on the SDC electrolyte, mainly because of the increase in the electrolyte conductivity and the decrease in the Si content at the electrode/electrolyte interface. NiO is able to restrict the diffusion of the siliceous impurity from the electrolyte to the electrode/electrolyte interface. Single cells based on SDC and SDCN electrolytes are fabricated using Ni0.9Cu0.1Ox-SDC as the anode and BCFN as the cathode. At 800 °C, the maximum power density of the SDCN-based cell is 0.745 W cm-2, which is much higher than that of the SDC-based cell.

  2. Study on BaO-Sm2O3-TiO2 Microwave Dielectric Ceramics Doped with Bismuth and Zinc

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    BaO-Sm2O3-TiO2 microwave dielectric ceramics doped with Bi and Zn was studied. The experiment was based on BST microwave dielectric ceramics doped with Bi2O3, which is shown by Ba4(Sm1-yBiy)28/3Ti18O54. When y=0.15, ZnO was added and the effects of ZnO on this system were studied. The result shows that the dielectric characteristics of BST microwave dielectric ceramics are the most excellent when the content of ZnO is 3%, and the optimal sintering temperature is 1200 ℃.

  3. Hydrogen content in doped and undoped BaPrO3 and BaCeO3 by cold neutron prompt-gamma activation analysis

    OpenAIRE

    Jones, Camille Y.; WU, Jian; Li, Liping; Haile, Sossina M.

    2005-01-01

    Proton uptake in undoped and Y-doped BaPrO3 has been measured by cold neutron prompt-gamma activation analysis, and compared to the proton uptake in Gd-doped BaCeO3, as determined by the same technique. The conventional proton incorporation model of perovskites in which oxygen ion vacancies, generated by the introduction of the trivalent dopant onto the tetravalent perovskite site, are filled with hydroxyl groups upon exposure of the sample to H2O containing atmospheres, predicts that the pro...

  4. Probing the (p,T) phase diagram of CeFe2 and SmS using resonant x-ray scattering

    International Nuclear Information System (INIS)

    Two strongly correlated electron systems CeFe2 and SmS have been studied using x-ray magnetic resonant scattering at low temperatures and high pressures. First, the magnetic ground state of CeFe2 doped with 7% Co has been probed by means of resonant x-ray magnetic scattering across the temperature range 10-95 K at pressures up to 9.5 kbar. A strong increase of the Neel temperature with pressure has been evidenced. Furthermore, a large increase in scattering intensity is observed just before TN at 9.5 k-bar. These results reveal that the itinerant character of the 4f electrons which stabilize the antiferromagnetic state has been probed. Secondly, the structural and electronic properties of SmS have been studied under pressure up to 29 k-bar and at temperatures down to 4.5 K via absorption and diffraction techniques. The measurements are a direct probe of the valence of Sm in SmS at low temperature from the black insulator phase to the gold metallic phase and furthermore across the magnetic transition. In particular, it is found that Sm in SmS has an intermediate valence (2.81(4)) in the magnetically ordered phase at 29 kbar and 4.5 K

  5. Photoluminescence properties of M{sub 2}Mg(BO{sub 3}){sub 2}:Sm{sup 3+} (M:Sr and Ba)

    Energy Technology Data Exchange (ETDEWEB)

    PEKGOeZLUe, Ilhan, E-mail: pekgozluilhan@yahoo.com [Bartin University, Faculty of Engineering, Department of Environmental Engineering, Bartin 74100 (Turkey)

    2013-02-15

    M{sub 2}Mg(BO{sub 3}){sub 2}:Sm{sup 3+} (M:Sr and Ba) phosphors were synthesized by a solution combustion synthesis method followed by heating of the precursor combustion ash at 900 Degree-Sign C in air. The synthesized materials were characterized by using the powder XRD. The emission and excitation spectra of these materials were measured at room temperature with a spectrofluorometer. Both Sr{sub 2}Mg(BO{sub 3}){sub 2}:Sm{sup 3+} and Ba{sub 2}Mg(BO{sub 3}){sub 2}:Sm{sup 3+} phosphors emit a strong in orange-red region. It was observed that the optimum concentration of Sm{sup 3+} in Sr{sub 2}Mg(BO{sub 3}){sub 2} and Ba{sub 2}Mg(BO{sub 3}){sub 2} are 0.01 and 0.04 mol, respectively. Finally, the relation between the photoluminescence properties of Sm{sup 3+} and host compositions was discussed in detail. - Highlights: Black-Right-Pointing-Pointer It has synthesized two novel inorganic borate phosphors for the first time. Black-Right-Pointing-Pointer The synthesized materials were characterized by using the powder X Ray Diffraction. Black-Right-Pointing-Pointer The photoluminescence properties of both phosphors were investigated using a spectrofluorometer. Black-Right-Pointing-Pointer Both Sr{sub 2}Mg(BO{sub 3}){sub 2}: Sm{sup 3+} and Ba{sub 2}Mg(BO{sub 3}){sub 2}: Sm{sup 3+} phosphors emit a strong in orange-red region.

  6. System Life Cycle Evaluation(SM) (SLiCE): harmonizing water treatment systems with implementers' needs.

    Science.gov (United States)

    Goodman, Joseph; Caravati, Kevin; Foote, Andrew; Nelson, Molly; Woods, Emily

    2013-06-01

    One of the methods proposed to improve access to clean drinking water is the mobile packaged water treatment system (MPWTS). The lack of published system performance comparisons combined with the diversity of technology available and intended operating conditions make it difficult for stakeholders to choose the system best suited for their application. MPWTS are often deployed in emergency situations, making selection of the appropriate system crucial to avoiding wasted resources and loss of life. Measurable critical-to-quality characteristics (CTQs) and a system selection tool for MPWTS were developed by utilizing relevant literature, including field studies, and implementing and comparing seven different MPWTS. The proposed System Life Cycle Evaluation (SLiCE) method uses these CTQs to evaluate the diversity in system performance and harmonize relevant performance with stakeholder preference via a selection tool. Agencies and field workers can use SLiCE results to inform and drive decision-making. The evaluation and selection tool also serves as a catalyst for communicating system performance, common design flaws, and stakeholder needs to system manufacturers. The SLiCE framework can be adopted into other emerging system technologies to communicate system performance over the life cycle of use.

  7. Synthesis, vacuum ultraviolet and ultraviolet spectroscopy of Ce3+ ion doped olgite Na(Sr, Ba)PO4

    International Nuclear Information System (INIS)

    Ce3+ ion doped olgite mineral samples, Na(Sr, Ba)PO4, were prepared by a high temperature solid-state reaction. The sample was investigated through x-ray powder diffraction, FT-IR and FT-Raman spectra measurements. The optical properties under vacuum ultraviolet (VUV) synchrotron radiation and ultraviolet (UV) irradiation are reported for the first time. The investigated samples show a strong absorption in the VUV and UV ranges. The bands corresponding to the 4f1 → 4f05d1 transitions of Ce3+ ions in the host lattices are identified. The barycentre of Ce3+ ions in the host lattices, the host absorption, the crystal field splitting, the emission and the Stokes shifts are presented and discussed. This Ce3+ ion doped material is a potential candidate for plasma display panel (PDP) application

  8. NUTRIENT ALLOCATION IN Eucalyptus saligna Sm. STANDS IN THE REGION OF GUAÍBA - RIO GRANDE DO SUL

    Directory of Open Access Journals (Sweden)

    Rudi Witschoreck

    2015-12-01

    Full Text Available This research conducted in Eucalyptus saligna Sm. stands, between 2 and 7 years of age, in the region of Guaíba - RS, had as objective: to estimate the nutrients stock in the biomass. On the basis of the forest inventory, trees of medium diameter were collected and fractionated in leaf, branch, bark, wood and root. The accumulated litter was evaluated with sampling units of 1 m2. Samples of arboreal components and litter were collected to estimate the dry matter and nutritional content. Nutrients stock was obtained through the product between the average biomass of each component and the average concentration of nutrients. For the average of stands, the stock of nutrients showed the following order of accumulation, for biomass components: wood > root > leaf > bark > branch; and for nutrients: Ca > N > K > Mg > P.

  9. Quantitative description of the phase transition of Aurivillius oxides Sm modified BaBi4Ti4O15 ceramics

    Science.gov (United States)

    Fang, Pinyang; Liu, Peng; Xi, Zengzhe

    2015-07-01

    BaBi4Ti4O15+xwt.%Sm2O3 (x=0.00, 0.25, 0.50, 0.75) ceramics were prepared by the solid-state reaction method. The effect of samarium additives on the structural and electrical properties of BBT ceramic was investigated. XRD patterns indicate that all ceramics are an m=4 members of Aurivillius oxides and no secondary phases were detected. A broad dielectric peak in frequency dependent dielectric spectrum is observed during the phase transition of all the BBT ceramics. The modified Curie-Weiss law, Vogel-Fucher relationship and Lorentz-type law were used to describe the phase transition behavior. The relaxor behavior was described well by the modified Curie-Weiss law and Vogel-Fucher relation. The effect of samarium additives on the degree of relaxation and diffuseness of BBT ceramics was discussed.

  10. Sm2NiSn4: The intermediate structure type between ZrSi2 and CeNiSi2

    International Nuclear Information System (INIS)

    A new rare earth nickel stannide, Sm2NiSn4, has been prepared by reacting the pure elements at high temperature in welded tantalum tubes. Its crystal structure was established by single crystal X-ray diffraction studies. Sm2NiSn4 crystallizes in the orthorhombic space group Pnma (No. 62) with cell parameters of a=16.878(2) A, b=4.4490(7) A, c=8.915(1) A, and Z=4. Its structure can be viewed as the intermediate type between ZrSi2 and CeNiSi2. Sm2NiSn4 features two-dimensional (2D) corrugated [NiSn4]6- layers in which the 1D Sn zigzag chains and the 2D Sn square sheets are bridged by Ni atoms. The Sm3+ cations are located at the interlayer space. Results of both resistivity measurements and extended-Hueckel tight-binding band structure calculations indicate that Sm2NiSn4 is metallic. -- Graphical Abstract: A new rare earth nickel stannide, Sm2NiSn4, has been prepared by the solid-state reactions of the corresponding pure elements at high temperature in welded tantalum tubes. Its structure can be viewed as the intermediate type between ZrSi2 and CeNiSi2. Sm2NiSn4 features 2D corrugated [NiSn4]6- layers in which the 1D Sn zigzag chains and the 2D Sn square sheets are bridged by Ni atoms. Results of both resistivity measurements and extended-Hueckel tight-binding band structure calculations indicate that Sm2NiSn4 is metallic

  11. Synthesis, characterization and TL response of Ce3+ activated BaMgAl10O17 phosphor

    International Nuclear Information System (INIS)

    Phosphor material BaMgAl10O17 with varying concentration of rare earth Ce3+ synthesis by combustion method at 500°C. The synthesized phosphor material characterized for their crystallinity and nature by XRD measurements. The thermoluminescecne response of phosphor exhibit TL spectra at 204°c and detailed analysis of kinetic parameter by de convoluted curve. These results show that concentration quenching occur at 5mol% of Ce dopant. The results suggest the possibility of utilizing as a phosphor may be in UV dosimeter and solid state lighting

  12. Dark decay behaviours of photorefractive grating induced by two deep-trap levels in Ce:BaTiO3

    Institute of Scientific and Technical Information of China (English)

    Zhang Ming; Xu Ying; Hong Zhi

    2005-01-01

    Dark decay behaviours of photorefractive grating in Ce:BaTiO3 crystal are studied experimentally. It is observed that two deep-trap levels, i.e. Fe-ion deep level and Ce-ion deep level, both participate in the photorefractive process. A simplified two-deep model is presented based on the one-deep trap model and the shallow-deep trap model, with which we analyse quantitatively the contribution of each deep level to the whole space-electric field and thus the photorefractive grating varying with the different grating wave vectors and different writing intensities.

  13. Synthesis and Fluorescence of BaYF5:Ce3+ Nanoparticles%BaYF5∶Ce3+纳米粒子的制备与光谱性质

    Institute of Scientific and Technical Information of China (English)

    闫景辉; 李中田; 郭海艳; 王琳琨; 曹亮军; 祁芸芸; 石春山

    2008-01-01

    在水/十六烷基三甲基溴化铵(CTAB)/正丁醇/正辛烷微乳液体系中成功的合成了BaYF5∶Ce3+纳米粒子. 运用X射线衍射(XRD)、环境扫描电子显微镜(ESEM)和荧光光谱等测试技术对所制备产物进行了表征. 样品的X射线衍射数据与PDF#46-39结果很好吻合,说明产物为BaYF5单一相,掺杂少量稀土离子对晶体结构未产生大的影响. 利用ESEM电子显微镜观察了产物的形貌. 结果表明,产物粒径均匀,直径在20 nm左右,呈球状外形. 利用荧光光谱仪测试了样品的激发和发射光谱,在330 nm处出现了发射峰. 分析结果表明,其归属于Ce3+的d-f跃迁,与体相BaYF5∶Ce3+相比蓝移了5 nm.

  14. Preparation of Sm2 O3 doped La2 Ce2 O7 ceramics for thermal barrier coatings by high temperature solid-state reaction%高温固相法制备Sm2O3掺杂La2Ce2O7热障涂层材料

    Institute of Scientific and Technical Information of China (English)

    毛亚南; 弓爱君; 邱丽娜; 曹艳秋; 原小涛; 童璐

    2015-01-01

    Sm2 O3 partly doped La2 Ce2 O7 ceramic materials for thermal barrier coatings were prepared by high temperature solid-state reaction using La2O3, CeO2 and Sm2O3 as raw materials. Their chemical formula is (SmxLa1-x)2Ce2O7. The phase composition of the samples was studied by X-ray diffraction ( XRD) . The doping ratio, firing temperature and firing time were investigated by an XRD pattern contrast analysis of the samples made in different conditions. It is found that the sample with fluorite structure has been prepared, and it can maintain its phase structure when the doping molar ratio Sm:La is 1:2 or 1:3. As the doping molar ratio Sm:La is 1:2 at the firing temperature of 1550℃ for 10 h, the prepared ( Sm0. 33 La0. 67 ) 2 Ce2 O7 has a good phase stability at 1600℃. This material can be potentially used as a new material for ceramic thermal barrier coatings.%以La2 O3、CeO2和Sm2 O3为原料,采用高温固相反应法制备了Sm2 O3部分掺杂La2 Ce2 O7热障涂层陶瓷材料,其化学式为(SmxLa1-x)2Ce2O7.采用X射线衍射法研究了试样的物相结构,并通过对比各实验条件下制备的试样的X射线衍射图谱,对试样的掺杂比例、烧制温度及烧制时间进行了探究.结果表明,所制备试样为萤石结构,当掺杂摩尔比Sm:La为1:2或1:3时试样均能保持良好的相结构,以掺杂摩尔比Sm:La=1:2制备的( Sm0.33 La0.67)2 Ce2 O7材料在1600℃下具有良好的相稳定性,且其最佳制备条件为1550℃下烧制10 h,该材料是一种很有潜力的新型热障涂层陶瓷材料.

  15. (La, Pr)0.8Sr0.2FeO3-δ-Sm 0.2Ce0.8O2-δ composite cathode for proton-conducting solid oxide fuel cells

    KAUST Repository

    Chen, Yonghong

    2014-08-01

    Mixed rare-earth (La, Pr)0.8Sr0.2FeO 3-δ-Sm0.2Ce0.8O2-δ (LPSF-SDC) composite cathode was investigated for proton-conducting solid oxide fuel cells based on protonic BaZr0.1Ce0.7Y 0.2O3-δ (BZCY) electrolyte. The powders of La 0.8-xPrxSr0.2FeO3-δ (x = 0, 0.2, 0.4, 0.6), Sm0.2Ce0.8O2-δ (SDC) and BaZr0.1Ce0.7Y0.2O3-δ (BZCY) were synthesized by a citric acid-nitrates self-propagating combustion method. The XRD results indicate that La0.8-xPrxSr 0.2FeO3-δ samples calcined at 950 °C exhibit perovskite structure and there are no interactions between LPSF0.2 and SDC at 1100 °C. The average thermal expansion coefficient (TEC) of LPSF0.2-SDC, BZCY and NiO-BZCY is 12.50 × 10-6 K-1, 13.51 × 10-6 K-1 and 13.47 × 10-6 K -1, respectively, which can provide good thermal compatibility between electrodes and electrolyte. An anode-supported single cell of NiO-BZCY|BZCY|LPSF0.2-SDC was successfully fabricated and operated from 700 °C to 550 °C with humidified hydrogen (∼3% H2O) as fuel and the static air as oxidant. A high maximum power density of 488 mW cm -2, an open-circuit potential of 0.95 V, and a low electrode polarization resistance of 0.071 Ω cm2 were achieved at 700 °C. Preliminary results demonstrate that LPSF0.2-SDC composite is a promising cathode material for proton-conducting solid oxide fuel cells. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  16. A New Combustion Process for Nanosized BaCe0.95Y0.05O3-δ Powders

    Institute of Scientific and Technical Information of China (English)

    孟波; 谭小耀; 张宝砚; 杨乃涛

    2004-01-01

    Nanosized BaCe0.95Y0.05O3-δ powders with the homogeneous composition were synthesized by a new combustion process based on the Pechini method.A polymeric precursor sol was formed by use of citric acid and ethylene glycol as the chelating agents of metal ions.The perovskite-type BaCe0.95Y0.05O3-δ powders with uniform shape and smaller than 40 nm in sized were obtained through the combustion of the polymeric precursor sol at the existence of nitric acid and ammonium hydroxide.It was found the particle size could be controlled by modulating the quantities of nitric acid and ammonium hydroxide,the quantities of the residue,carbonate ions were also affected by the quantities of the citric acid and ethylene glycol.

  17. Synthesis and luminescence property of Li{sub 2}BaP{sub 2}O{sub 7}:Ln{sup 3+} (Ln=Eu, Sm) phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Wani, J.A. [Department of Physics, R.T.M. Nagpur University, Nagpur 440033 (India); Dhoble, N.S. [Department of Chemistry, Sevadal Mahila Mahavidhyalaya, Nagpur 440009 (India); Kokode, N.S. [BCUD Gondwana University, Gadchiroli (India); Deva Prasad Raju, B. [Department of Future studies, Sri Venkateswara University, Tirupati 517502 (India); Dhoble, S.J., E-mail: sjdhoble@rediffmail.com [Department of Physics, R.T.M. Nagpur University, Nagpur 440033 (India)

    2014-03-15

    Phosphate compounds as host materials are always a good choice for lanthanides to exhibit luminescence. The novel phosphors of Li{sub 2}BaP{sub 2}O{sub 7} activated with the trivalent Eu{sup 3+} and Sm{sup 3+} ions were synthesized by high temperature solid state reaction. In characterization, crystallization, morphology and luminescent properties of lithium barium diphosphate were investigated. The excitation and emission spectra were recorded to study the luminescence properties. The as prepared powders of Eu{sup 3+} and Sm{sup 3+} ions doped Li{sub 2}BaP{sub 2}O{sub 7} emit reddish orange light, corresponding to {sup 5}D{sub 0}→{sup 7}F{sub 1}(595 nm) and {sup 4}G{sub 5/2}→{sup 6}H{sub 7/2}(599 nm) transitions, respectively. The study is novel as no such luminescence data are available for this compound. -- Highlights: • Luminescence characterization of Li{sub 2}BaP{sub 2}O{sub 7}:Sm{sup 3+}, Eu{sup 3+} prepared phosphors are first time reported in this paper. • Sm{sup 3+} ions luminescence quenches just after 0.5 mol% in Li{sub 2}BaP{sub 2}O{sub 7}:Sm{sup 3+} phosphor. • Excitation wavelengths are quite far away from mercury, hence Li{sub 2}BaP{sub 2}O{sub 7}:Sm{sup 3+}, Eu{sup 3+} is eco-friendly materials for lighting. • {sup 5}D{sub 0}→{sup 7}F{sub 1} and {sup 4}G{sub 5/2}→{sup 6}H{sub 7/2} transitions are dominant in Li{sub 2}BaP{sub 2}O{sub 7}:Sm{sup 3+}, Eu{sup 3+} indicates local symmetry.

  18. Space-Selective Precipitation of Ba2TiSi2O8 Crystals in Sm3+-Doped BaO-TiO2-SiO2 Glass by Femtosecond Laser Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHU Bin; DAI Ye; MA Hong-Liang; LIN Geng; QIU Jian-Rong

    2008-01-01

    The ferroelectric crystal Ba2TiSi2O8 with high second-order optical nonlinearity is precipitated in Sm3+-doped BaO-TiO2-SiO2 glass by a focused 800 nm,250 kHz and 150 fs femtosecond laser irradiation.No apparent blue and red emissions are observed at the beginning,while strong blue emission due to second harmonic generation and red emission due to the f-f transitions of Sm3+ are observed near the focal point of the laser beam after irradiation for 25 s. Micro-Raman spectra confirm that Ba2TiSi2O8 crystalline dots and lines are formed after laser irradiation.The mechanism of the phenomenon is discussed.

  19. Electrochemical and catalytic properties of Ni/BaCe0.75Y0.25O3-δ anode for direct ammonia-fueled solid oxide fuel cells.

    Science.gov (United States)

    Yang, Jun; Molouk, Ahmed Fathi Salem; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2015-04-01

    In this study, Ni/BaCe0.75Y0.25O3-δ (Ni/BCY25) was investigated as an anode for direct ammonia-fueled solid oxide fuel cells. The catalytic activity of Ni/BCY25 for ammonia decomposition was found to be remarkably higher than Ni/8 mol % Y2O3-ZrO2 and Ni/Ce0.90Gd0.10O1.95. The poisoning effect of water and hydrogen on ammonia decomposition reaction over Ni/BCY25 was evaluated. In addition, an electrolyte-supported SOFC employing BaCe0.90Y0.10O3-δ (BCY10) electrolyte and Ni/BCY25 anode was fabricated, and its electrochemical performance was investigated at 550-650 °C with supply of ammonia and hydrogen fuel gases. The effect of water content in anode gas on the cell performance was also studied. Based on these results, it was concluded that Ni/BCY25 was a promising anode for direct ammonia-fueled SOFCs. An anode-supported single cell denoted as Ni/BCY25|BCY10|Sm0.5Sr0.5CoO3-δ was also fabricated, and maximum powder density of 216 and 165 mW cm(-2) was achieved at 650 and 600 °C, for ammonia fuel, respectively.

  20. Characterization of an optically stimulated luminescence (OSL) material for thermal neutron detection: SrS:Ce,Sm,B

    Energy Technology Data Exchange (ETDEWEB)

    Ravotti, Federico [Institut d' Electronique du Sud (IES), UMR UM2-CNRS 5214, Universite Montpellier 2, Place Eugene Bataillon - CC 083, 34095 Montpellier Cedex 5 (France); CERN, Physics Department, 1211 Geneva 23 (Switzerland); Garcia, Pierre; Prevost, Hildegarde; Dusseau, Laurent [Institut d' Electronique du Sud (IES), UMR UM2-CNRS 5214, Universite Montpellier 2, Place Eugene Bataillon - CC 083, 34095 Montpellier Cedex 5 (France); Lapraz, Dominique [Laboratoire de Physique Electronique des Solides (LPES), Centre de Recherches sur les Solides et leurs Applications (CRESA), EA 1174, Faculte des Sciences, Universite de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2 (France); Vaille, Jean-Roch [Institut d' Electronique du Sud (IES), UMR UM2-CNRS 5214, Universite Montpellier 2, Place Eugene Bataillon - CC 083, 34095 Montpellier Cedex 5 (France); Universite de Nimes, Site des Carmes, Place Gabriel Peri, 30021 Nimes Cedex 01 (France); Benoit, David

    2008-05-15

    SrS:Ce,Sm exhibits some interesting phosphorescent and charge storage properties that are used in OSL (optically stimulated luminescence) radiation dosimetry. To enhance the thermal neutron sensitivity of this phosphor, a new material obtained by boron doping has been developed. This OSL, B material was analysed with respect to its optical and structural characteristics in order to study possible modifications induced by doping procedure. Optical study highlights a decrease in the material luminescence of about 40% with TL and OSL experiments. The emission spectrum remains the same after boron addition. This result is in agreement with the structural characterization analysis since the lattice parameters were not modified. 11B MAS NMR results indicate that boron atoms are present in the host lattice in form of BO4 groups. Consequences on dosimetry applications are discussed. The neutron response of the OSL, B irradiated in a nuclear reactor is linear up to a fluence of 5 x 1011 cm{sup -2} and it is possible to separate the thermal neutron and gamma components. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Mobilidade de oxigênio intersticial em cerâmicas SmBa2Cu3O7-delta Mobility of interstitial oxygen in SmBa2Cu3O7-delta ceramics

    Directory of Open Access Journals (Sweden)

    R. M. Nascimento

    2005-09-01

    Full Text Available Desde a descoberta dos supercondutores com alta temperatura crítica, vários trabalhos têm sido efetuados sobre as diferentes propriedades destes materiais. As cerâmicas YBa2Cu3O7-delta mostraram que têm suas propriedades supercondutoras fortemente afetadas pela quantidade de oxigênio. Mais recentemente, medidas de relaxação anelástica em La2CuO4+delta mostraram que a remoção deste elemento pode ser relacionada com dois eventos. Um deles é o decréscimo na mobilidade entre dois planos adjacentes CuO e o outro, é o aumento no número de padrões de mobilidade para os octaedros CuO6. Para SmBa2Cu3O7 (SBCO, a possibilidade de uma estequiometria de oxigênio variável e sua alta mobilidade nos planos CuOx, dá origem a um diagrama de fases bastante rico. Neste trabalho, são reportadas medidas de espectroscopia anelástica em amostras de SBCO, que mostram um pico de relaxação termicamente ativado, que foi atribuído aos saltos de átomos de oxigênio nas posições O1 e O5 da rede.Since the discovery of the high-Tc superconductors, several works have been made about the different properties of these materials. The YBa2Cu3O7-delta ceramic showed to have its superconducting properties strongly affected by the oxygen content. More recently, anelastic relaxation measurements in La2CuO4+delta, showed that the removal of this element can be related to two events. One is the decrease in mobility between two adjacent CuO planes, and the other is the increase in the number of tilting patterns of the CuO6 octahedra. For SmBa2Cu3O7 (SBCO, the possibility of variable stoichiometry and the high mobility of oxygen in the CuOx planes give rise to a rich phase diagram. In this paper, anelastic spectroscopy measurements are reported in SBCO samples which shown a thermally activated relaxation peak that was attributed to the jumps of the oxygen atoms in the inter-chains O1 and O5 of the lattice.

  2. Fabrication and Mechanical Properties of Sm2O3 Doped CeO2 Reinforced Ti3AlC2 Nano Composite

    Institute of Scientific and Technical Information of China (English)

    Jae Ho Han; Sang Whan Park; Young Do Kim

    2004-01-01

    The fabrication process of Sm2O3 doped CeO2 reinforced Ti3AlC2 nano composites including the nano particle dispersion process by a hetero-coagulation process was developed using in-situ synthesis and densification process of Ti3AlC2. The effects of Sm2O2 doped CeO2 nano particles on mechanical properties of Ti3AlC2 were investigated. It was found that the presence of 20SDC nano particles in Ti3AlC2 was very effective to improve the mechanical properties of Ti3AlC2 without spoiling the unique characteristics of Ti3AlC2temary carbide.

  3. Anisotropic superconducting-state thermodynamic parameters of the electron-doped compound Sm1.85Ce0.15CuO4-y

    International Nuclear Information System (INIS)

    The anisotropic superconducting-state thermodynamic parameters of the electron-doped compound Sm1.85Ce0.15CuO4-y have been derived from reversible dc magnetization M(H,T) measurements on magnetically aligned single-crystal particles of the compound for magnetic fields applied perpendicular and parallel to the ab plane. A recent model developed by Hao et al., which describes M(H,T) over the entire field region between Hc1 and Hc2, was used to analyze the M(H,T) data. The analysis of the measurements provides a self-consistent test of the model and resolves a controversy by showing that the anisotropy of Hc2(T) of the electron-doped compound Sm1.85Ce0.15CuO4-y is comparable to that of the hole-doped compound YBa2Cu3O7-δ

  4. Ultraviolet-vacuum ultraviolet photoluminescence and x ray radioluminescence of Ce3+-doped Ba3MgSi2O8

    NARCIS (Netherlands)

    Ding, X.; Liang, H.; Hou, D.; Su, Q.; Dorenbos, P.; Sun, S.; Tao, Y.

    2011-01-01

    Ce3+-doped Ba3MgSi2O8 phosphors were prepared by a solid-state reaction route. The photoluminescence properties in the vacuum ultraviolet-vis spectral range and the x ray excited radioluminescence were investigated. Ce3+ ions were found to enter three different sites in the host lattice. Five excita

  5. Sm 2NiSn 4: The intermediate structure type between ZrSi 2 and CeNiSi 2

    Science.gov (United States)

    Sun, Zhong-Ming; Pan, Da-Chun; Lei, Xiao-Wu; Mao, Jiang-Gao

    2006-11-01

    A new rare earth nickel stannide, Sm 2NiSn 4, has been prepared by reacting the pure elements at high temperature in welded tantalum tubes. Its crystal structure was established by single crystal X-ray diffraction studies. Sm 2NiSn 4 crystallizes in the orthorhombic space group Pnma (No. 62) with cell parameters of a=16.878(2) Å, b=4.4490(7) Å, c=8.915(1) Å, and Z=4. Its structure can be viewed as the intermediate type between ZrSi 2 and CeNiSi 2. Sm 2NiSn 4 features two-dimensional (2D) corrugated [NiSn 4] 6- layers in which the 1D Sn zigzag chains and the 2D Sn square sheets are bridged by Ni atoms. The Sm 3+ cations are located at the interlayer space. Results of both resistivity measurements and extended-Hückel tight-binding band structure calculations indicate that Sm 2NiSn 4 is metallic.

  6. Photon management properties of rare-earth (Nd,Yb,Sm)-doped CeO2 films prepared by pulsed laser deposition.

    Science.gov (United States)

    Balestrieri, Matteo; Colis, Silviu; Gallart, Mathieu; Schmerber, Guy; Bazylewski, Paul; Chang, Gap Soo; Ziegler, Marc; Gilliot, Pierre; Slaoui, Abdelilah; Dinia, Aziz

    2016-01-28

    CeO2 is a promising material for applications in optoelectronics and photovoltaics due to its large band gap and values of the refractive index and lattice parameters, which are suitable for silicon-based devices. In this study, we show that trivalent Sm, Nd and Yb ions can be successfully inserted and optically activated in CeO2 films grown at a relatively low deposition temperature (400 °C), which is compatible with inorganic photovoltaics. CeO2 thin films can therefore be efficiently functionalized with photon-management properties by doping with trivalent rare earth (RE) ions. Structural and optical analyses provide details of the electronic level structure of the films and of their energy transfer mechanisms. In particular, we give evidence of the existence of an absorption band centered at 350 nm from which energy transfer to rare earth ions occurs. The transfer mechanisms can be completely explained only by considering the spontaneous migration of Ce(3+) ions in CeO2 at a short distance from the RE(3+) ions. The strong absorption cross section of the f-d transitions in Ce(3+) ions efficiently intercepts the UV photons of the solar spectrum and therefore strongly increases the potential of these layers as downshifters and downconverters. PMID:26699802

  7. Diffusion of Zr, Ru, Ce, Y, La, Sr and Ba fission products in UO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Perriot, R., E-mail: rperriot@lanl.gov; Liu, X.-Y.; Stanek, C.R.; Andersson, D.A.

    2015-04-15

    The diffusivity of the solid fission products (FP) Zr (Zr{sup 4+}), Ru (Ru{sup 4+}, Ru{sup 3+}), Ce (Ce{sup 4+}), Y (Y{sup 3+}), La (La{sup 3+}), Sr (Sr{sup 2+}) and Ba (Ba{sup 2+}) by a vacancy mechanism has been calculated, using a combination of density functional theory (DFT) and empirical potential (EP) calculations. The activation energies for the solid fission products are compared to the activation energy for Xe fission gas atoms calculated previously. Apart from Ru, the solid fission products all exhibit higher activation energy than Xe. For all solid FPs except Y{sup 3+}, the migration of the FP has lower barrier than the migration of a neighboring U atom, making the latter the rate limiting step for direct migration. An indirect mechanism, consisting of two successive migrations around the FP, is also investigated. The calculated diffusivities show that most solid fission products diffuse with rates similar to U self-diffusion. However, Ru, Ba and Sr exhibit faster diffusion than the other solid FPs, with Ru{sup 3+} and Ru{sup 4+} diffusing even faster than Xe for T < 1200 K. The diffusivities correlate with the observed fission product solubility in UO{sub 2}, and the tendency to form metallic and oxide second phase inclusions.

  8. Optical characterization and the energy level scheme for NaYP{sub 2}O{sub 7}:Ln{sup 3+} (Ln=Ce, Sm, Eu, Tb, Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Novais, S.M.V., E-mail: suellenvaleriano@yahoo.com.br [Laboratory of Advanced Ceramic Materials, Physics Department, Federal University of Sergipe, 49.100-000, São Cristóvão, SE (Brazil); Dobrowolska, A.; Bos, A.J.J.; Dorenbos, P. [Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Macedo, Z.S. [Laboratory of Advanced Ceramic Materials, Physics Department, Federal University of Sergipe, 49.100-000, São Cristóvão, SE (Brazil)

    2014-04-15

    Vacuum ultra-violet spectroscopy at low temperature was performed with undoped and Ln{sup 3+}-doped NaYP{sub 2}O{sub 7} (Ln=Ce, Sm, Eu, Tb and Yb). The emission observed from the NaYP{sub 2}O{sub 7} host was attributed to self-trapped exciton (STE) recombination. Dopant ions were well incorporated and responsible for characteristic luminescent emission in the doped samples. From excitation curves, 4f–5d transitions were identified for Ce{sup 3+}, Sm{sup 3+} and Tb{sup 3+} and charge transfer processes were noticed for Eu{sup 3+}, Sm{sup 3+} and Yb{sup 3+}. The experimental data obtained was used to determine the positions of the energy levels of divalent and trivalent lanthanides relative to the valence and conduction band of this compound. The experimentally derived levels are in good agreement with model predictions. The results are valuable to provide a better understanding on the performance of NaYP{sub 2}O{sub 7} and related diphosphates as luminescent materials. -- Highlights: • NaYP{sub 2}O{sub 7} polycrystalline samples were produced via the sol–gel method. • VUV excitation and emission spectra were successfully studied. • Luminescent properties were discussed. • The experimentally derived energy levels are in good agreement with model predictions.

  9. Characterization and properties of new dielectric ceramics Ba5LnZnNb9O30(Ln=La,Nd and Sm)

    Institute of Scientific and Technical Information of China (English)

    ZHU Wen-feng; HU Chang-zheng; WU Bo-lin; FANG Liang

    2006-01-01

    Three novel dielectric ceramics Ba5LnZnNb9O30 (Ln= La,Nd and Sm) were synthesized and characterized in the BaO-Ln2O3-ZnO-Nb2O5 quaternary system,which formed the filled tungsten-bronze structures. The present ceramics exhibit high dielectric constant (εr) up to 310,low dielectric loss in the level of 10-3 at 1 MHz . Meanwhile,the temperature coefficients of the dielectric constant (τε) of Ba5LnZnNb9O30 varies from -1 390×10-6 to -1 220×10-6/℃ as the radius of Ln3+ increases. The present ceramics are promising candidates for high dielectric constant and low loss dielectric ceramics.

  10. Fabrication of High-Quality SmBa2Cu3O7-δ Thin Films by a Modified TFA-MOD Process

    International Nuclear Information System (INIS)

    We report a successful fabrication of high-quality SmBa2Cu3O7-δ (SmBCO) thin films on LaAlO3(LAO)(100) single crystalline substrates by a modified TFA-MOD method. After the pyrolysis heat treatment of spin-coated films up to 400 degree C, SmBCO films were fired at various temperatures ranging from 810 to 850 degree C in a reduced oxygen atmosphere (10 ppm O2 in Ar). Optimally processed SmBCO films exhibited the zero-resistance temperature (Tc,zero) of 90.2 K and the critical current density (Jc) of 0.8 MA/cm2 at 77K in self-field. Compared with the Jc values (normally, > 2 MA/cm2 at 77 K) of MOD-TFA processed YBCO films, rather depressed Jc values in SmBCO films are most probably attributed to the existence of alpha-axis oriented grains.

  11. The deposition of Sm1Ba2Cu3O7-δ on SrTiO3 using co-evaporation method

    Science.gov (United States)

    Kim, H. S.; Ha, H. S.; Kim, T. H.; Yang, J. S.; Ko, R. K.; Song, K. J.; Ha, D. W.; Lee, N. J.; Oh, S. S.; Youm, D. J.; Park, Chan

    2007-09-01

    The SmBCO(Sm 1Ba 2Cu 3O 7- δ) films were deposited on SrTiO 3 substrates using co-evaporation method. The deposition system was specially designed, that is named evaporation using drum in dual chambers, as the following features. The deposition system consists of reaction chamber and evaporation one. The role of reaction chamber is for the deposited materials to react with oxygen gas, and that of the evaporation chamber is to evaporate the composing elements of SmBCO, respectively. The composition ratio of SmBCO is controlled by the deposition rate of each element. The drum of 50 cm of diameter and 72 cm of length is located between the reaction chamber and the evaporation chamber. By rotating the drum, deposition and reaction process are repeated. In this system, SmBCO films were deposited on SrTiO 3 single crystal substrates. We obtained Ic and Jc results of 83.3 A/cm and 2.1 MA/cm 2 at 77 K in self-field.

  12. Electrical conductivity and chemical stability of BaCe0.8−AGd0.2O3− (A = In, Zr, Ta; = 0, 0.1) ceramics

    Indian Academy of Sciences (India)

    Xiao-Ming Liu; Yi-Jing Gu; Zhan-Guo Liu; Jia-Hu Ouyang; Fu-Yao Yan; Jun Xiang

    2013-06-01

    BaCe0.8−AGd0.2O3− (A = In, Zr, Ta; = 0, 0.1) ceramics were synthesized by solid-state reaction method. Microstructure and electrical properties of BaCe0.8−AGd0.2O3− ceramics were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and complex impedance analysis at intermediate temperatures of 573–1073 K in different atmospheres. BaCe0.8Gd0.2O3−, BaCe0.7In0.1Gd0.2O3− and BaCe0.7Zr0.1Gd0.2O3− ceramics exhibit a single cubic perovskite structure. BaCe0.7In0.1Gd0.2O3− ceramic has the highest conductivity of 4.6 × 10-2 S.cm-1 in air at 1073 K. BaCe0.7In0.1Gd0.2O3− and BaCe0.7Zr0.1Gd0.2O3− ceramics exhibit an excellent chemical stability against boiling water. Indium is a suitable doping element to promote the sintering densification and to enhance both electrical conductivity and chemical stability of Gd-doped BaCeO3 at operating temperatures.

  13. Study of vibrational spectroscopy, linear and non-linear optical properties of Sm3+ ions doped BaO-ZnO-B2O3 glasses

    Science.gov (United States)

    Nanda, Kirti; Kundu, R. S.; Sharma, Sarita; Mohan, Devendra; Punia, R.; Kishore, N.

    2015-07-01

    Samarium oxide doped Barium-Zinc-Borate glasses with compositions xSm2O3-(100-x)[0.1BaO-0.4ZnO-0.5B2O3]; x = 0.0, 0.5, 1.0, 1.5 and 2.0 have been prepared by melt quench technique. The amorphous nature of as-prepared glasses has been ascertained by X-ray diffraction patterns. The observed values of density and molar volume of the glass samples are found to increase with the increase in concentration of Sm2O3. Fourier Transform Infrared spectra of the prepared glasses indicate that Sm2O3 acts as glass modifier. With the increase in Sm2O3 content, BO4 structural units start converting into BO3 structural units. The values of optical energy band gap (Eg), estimated from Tauc's plots, are observed to decrease with the increase in Sm2O3 content. The nonlinear optical properties of glass samples have been investigated by Z-scan method with nanosecond pulsed laser at ˜532 nm in both open and close aperture geometries. The values of two photon absorption coefficient (β) and nonlinear refractive index (n2) have been estimated by fitting of experimentally observed data with theoretical models and both are found to increase with the increase in Sm3+ ions concentration in the glass matrix. The total third order nonlinear susceptibility (χ(3)) have been calculated and observed to increase with the increase in Sm3+ ions concentration.

  14. Crystal structures of R{sub 2}Pd{sub 2}Pb (R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Melnyk, G.; Kandpal, H.C.; Gulay, L.D.; Tremel, W

    2004-05-12

    The crystal structures of the R{sub 2}Pd{sub 2}Pb (R=Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu) compounds were determined using X-ray powder diffraction. The investigated compounds crystallize with Mo{sub 2}FeB{sub 2} structure type (space group P4/mbm, Pearson code tP10). The importance of stabilization by polar intermetallic R-Pd bonding is underscored by a bonding analysis derived from electronic band structure calculations.

  15. Synthesis and characterization of Ce_(0.8)Sm_(0.2)O_(1.9) nanopowders using an acrylamide polymerization process

    Institute of Scientific and Technical Information of China (English)

    郑颖平; 王绍荣; 王振荣; 邬理伟; 孙岳明

    2010-01-01

    Ce0.8Sm0.2O1.9(SDC) nanopowders were synthesized by an acrylamide polymerization process.The XRD results showed that SDC powders prepared at 700 °C possessed a cubic fluorite structure.Transmission electron microscopy(TEM) indicated that the particle sizes of powders were in the range of 10-15 nm.A 98.3% of theoretical density was obtained when the SDC pellets were sintered at 1350 °C for 5 h,indicating that the powders had good sinterability.The conductivity of the sintered SDC ceramics was 0.019 S/cm at 6...

  16. Crystal structures of the compounds R{sub 3}CuSiS{sub 7} (R = Ce, Pr, Nd, Sm, Tb, Dy and Er) and R{sub 3}CuSiSe{sub 7} (R = La, Ce, Pr, Nd, Sm, Gd, Tb and Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine)]. E-mail: gulay@univer.lutsk.ua; Lychmanyuk, O.S. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine); Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine); Daszkiewicz, M. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna str. 2, P.O. Box 1410, 50-950 Wroclaw (Poland); Stepien-Damm, J. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna str. 2, P.O. Box 1410, 50-950 Wroclaw (Poland); Pietraszko, A. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna str. 2, P.O. Box 1410, 50-950 Wroclaw (Poland)

    2007-04-04

    The crystal structures of the compounds R{sub 3}CuSiS{sub 7} (R = Ce, Pr, Nd, Sm, Tb, Dy and Er) and R{sub 3}CuSiSe{sub 7} (R = La, Ce, Pr, Nd, Sm, Gd, Tb and Dy) (La{sub 3}CuSiS{sub 7} structure type, space group P6{sub 3}, Pearson symbol hP24) were determined by means of X-ray single crystal and powder diffraction. The R atoms are surrounded by distorted trigonal prisms. A triangular surrounding exists for the Cu atoms. A tetrahedral surrounding exists for the Si atoms. The S(Se)1 and S(Se)3 atoms are surrounded by tetrahedra also. Four cations surround every S(Se)2 atom.

  17. Luminescence properties and energy transfer in the novel red emitting phosphors Ba{sub 2}Ln(BO{sub 3}){sub 2}Cl:Sm{sup 3+}, Eu{sup 3+} (Ln=Y, Gd)

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Yan; Hu, Yihua, E-mail: huyh@gdut.edu.cn; Chen, Li; Wang, Xiaojuan; Ju, Guifang

    2014-10-01

    A series of Sm{sup 3+}/Eu{sup 3+} singly and co-doped Ba{sub 2}Ln(BO{sub 3}){sub 2}Cl (Ln=Y{sup 3+}, Gd{sup 3+}) phosphors were prepared via the solid-state method. The XRD results indicate that the as-prepared products keep the monoclinic structure with a P{sub 21/m} space group of Ba{sub 2}Ln(BO{sub 3}){sub 2}Cl, which belongs to the isomorphic substitution for Ln{sup 3+} sites in the Ba{sub 2}Yb(BO{sub 3}){sub 2}Cl host. The photoluminescence (PL) spectra demonstrate that Ba{sub 2}Ln(BO{sub 3}){sub 2}Cl:Sm{sup 3+},Eu{sup 3+} emits red light centered at 593 nm under the 393 nm excitation which is in good agreement with the emission wavelength from near ultraviolet light-emitting diodes (LEDs). The luminescence decays suggest that the energy transfer from Sm{sup 3+} to Eu{sup 3+} ions in Ba{sub 2}Ln(BO{sub 3}){sub 2}Cl:Eu{sup 3+}, Sm{sup 3+} occurs. All results mean that Ba{sub 2}Ln(BO{sub 3}){sub 2}Cl:Eu{sup 3+}, Sm{sup 3+} phosphors exhibit potential to act as a kind of red phosphor for near ultraviolet white light-emitting diodes (w-LEDs)

  18. Color tuning of Ba{sub 2}ZnSi{sub 2}O{sub 7}:Ce{sup 3+}, Tb{sup 3+} phosphor via energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhongfu; Hu, Yihua, E-mail: huyh@gdut.edu.cn; Chen, Li; Wang, Xiaojuan

    2014-09-15

    A series of Ce{sup 3+} or Tb{sup 3+} doped and Ce{sup 3+}/Tb{sup 3+} co-doped Ba{sub 2}ZnSi{sub 2}O{sub 7} phosphors were prepared via the conventional high temperature solid state reaction method. The photoluminescence and energy transfer properties of samples were studied in detail. The optimal proportion of Ce{sup 3+} single doping is 2 mol% with maximal fluorescence intensity. Ba{sub 1.98−x}ZnSi{sub 2}O{sub 7}:0.02Ce{sup 3+}, xTb{sup 3+} shows both a blue emission (428 nm) from Ce{sup 3+} and a yellowish-green emission (542 nm) from Tb{sup 3+} with considerable intensity under ultraviolet (UV) excitation (352 nm). The emission chromaticity coordinates can be adjusted from blue to green region by tuning the concentration of Tb{sup 3+} ions from 0.00 to 0.06 through an energy transfer process. The energy transfer mechanism from Ce{sup 3+} to Tb{sup 3+} ions was proved to be dipole–dipole interaction. The Ce{sup 3+} and Tb{sup 3+} co-doped Ba{sub 2}ZnSi{sub 2}O{sub 7} phosphors are potential UV-convertible candidates with green light emitting in UV-LEDs for the high efficient energy transfer from Ce{sup 3+} to Tb{sup 3+} ions. - Highlights: • The emission color can be adjusted from blue to green region by tuning the concentration of Tb{sup 3+} ions. • There is very high transfer efficiency with the maximal value 84.4% from Ce{sup 3+} to Tb{sup 3+}. • The energy transfer mechanism from Ce{sup 3+} to Tb{sup 3+} ions was proved to be dipole–dipole interaction.

  19. Blue-green tunable color of Ce3+/Tb3+ coactivated NaBa3La3Si6O20 phosphor via energy transfer

    Science.gov (United States)

    Jia, Zhen; Xia, Mingjun

    2016-01-01

    A series of color tunable phosphors NaBa3La3Si6O20:Ce3+, Tb3+ were synthesized via the high-temperature solid-state method. NaBa3La3Si6O20 crystallizes in noncentrosymmetric space group Ama2 with the cell parameters of a = 14.9226(4) Å, b = 24.5215(5) Å and c = 5.6241(2) Å by the Rietveld refinement method. The Ce3+ ions doped NaBa3La3Si6O20 phosphors have a strong absorption band from 260 to 360 nm and show near ultraviolet emission light centered at 378 nm. The Ce3+ and Tb3+ ions coactivated phosphors exhibit color tunable emission light from deep blue to green by adjusting the concentration of the Tb3+ ions. An energy transfer of Ce3+ → Tb3+ investigated by the photoluminescence properties and lifetime decay, is demonstrated to be dipole–quadrupole interaction. These results indicate the NaBa3La3Si6O20:Ce3+, Tb3+ phosphors can be considered as potential candidates for blue-green components for white light emitting diodes. PMID:27628111

  20. Crystal structures and magnetic properties of R{sub 2}PbSi{sub 2}S{sub 8} (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho), R{sub 2}PbSi{sub 2}Se{sub 8} (R = La, Ce, Pr, Nd, Sm, Gd) and R{sub 2}PbGe{sub 2}S{sub 8} (R = Ce, Pr) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Daszkiewicz, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland); Marchuk, O.V. [Department of Inorganic and Physical Chemistry, Volyn National University, Voli Ave 13, 43009 Lutsk (Ukraine); Gulay, L.D. [Department of Ecology and Protection of Environment, Volyn National University, Voli Ave 13, 43009 Lutsk (Ukraine); Kaczorowski, D., E-mail: D.Kaczorowski@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland)

    2012-04-05

    The crystal structures of several novel quaternary compounds R{sub 2}PbSi{sub 2}S{sub 8} (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho), R{sub 2}PbSi{sub 2}Se{sub 8} (R = La, Ce, Pr, Nd, Sm, Gd) and R{sub 2}PbGe{sub 2}S{sub 8} (R = Ce, Pr) have been determined by means of single-crystal and powder X-ray diffraction. All these phases crystallize with hexagonal unit cells of the La{sub 2}PbSi{sub 2}S{sub 8} type (space group R-3c, Pearson symbol hR78), in which rare-earth and lead atoms are statistically distributed over centers of bi-capped trigonal prisms made by chalcogen atoms. The magnetic properties of R{sub 2}PbSi{sub 2}S{sub 8} and R{sub 2}PbSi{sub 2}Se{sub 8} with R = La, Ce, Pr and Sm have been studied in wide temperature and magnetic field ranges. The La-based materials are weakly diamagnetic, whereas all the other compounds exhibit strongly temperature dependent paramagnetic behaviour due to the presence of well localized magnetic moments of trivalent rare-earth ions.

  1. Luminescent properties and energy transfer process of Sm3+-Eu3+ co-doped MY2(MoO4)4 (M=Ca, Sr and Ba) red-emitting phosphors

    Science.gov (United States)

    Ye, Menglin; Zhou, Gaojian; Zhou, Liqun; Lu, Di; Li, Yue; Xiong, Xing; Yang, Kunzhou; Chen, Menghuan; Pan, Yaxi; Wu, Peng; Wang, Zheng; Liu, Hongying; Xia, Qinghua

    2016-09-01

    MY2(MoO4)4:Sm3+ and MY2(MoO4)4:xSm3+,yEu3+ (M=Ca, Sr and Ba) phosphors were successfully prepared using solid-state reaction route, and their luminescent properties and energy transfer process from Sm3+ to Eu3+ were systematically investigated. The results indicate that MY2(MoO4)4:Sm3+ phosphors can be effectively excited by 407 nm near UV light originating from the 6H5/2 → 4F7/2 transition of Sm3+, and exhibit a satisfactory red emission at 646 nm attributed to the 4G5/2 → 6H9/2 transition of Sm3+, in which the emission intensity of SrY2(MoO4)4:Sm3+ is the strongest among the MY2(MoO4)4:Sm3+ (M=Ca, Sr and Ba) phosphors. For Eu3+ co-doped MY2(MoO4)4:Sm3+ samples, with increasing Eu3+ doping content, the main emission peaks of Sm3+ (approximately 646 nm) are decreased, but the emission peaks and intensity of Eu3+ are increased while the maximum intensity of luminescence at the Eu3+ concentration 0.9. The introduction of Eu3+ in the MY2(MoO4)4:Sm3+ phosphors can remarkably generate a strong emission line at 616 nm, originating from the 5D0→7F2 transition of Eu3+ and Sm3+ (4G5/2) → Eu3+ (5D0) effective energy transfer process. The energy transfer mechanism from Sm3+ to Eu3+ was discussed in detail.

  2. Synthesis and in vitro microbial evaluation of La(III), Ce(III), Sm(III) and Y(III) metal complexes of vitamin B6 drug

    Science.gov (United States)

    Refat, Moamen S.; Al-Azab, Fathi M.; Al-Maydama, Hussein M. A.; Amin, Ragab R.; Jamil, Yasmin M. S.

    2014-06-01

    Metal complexes of pyridoxine mono hydrochloride (vitamin B6) are prepared using La(III), Ce(III), Sm(III) and Y(III). The resulting complexes are investigated. Some physical properties, conductivity, analytical data and the composition of the four pyridoxine complexes are discussed. The elemental analysis shows that the formed complexes of La(III), Ce(III), Sm(III) and Y(III) with pyridoxine are of 1:2 (metal:PN) molar ratio. All the synthesized complexes are brown in color and possess high melting points. These complexes are partially soluble in hot methanol, dimethylsulfoxide and dimethylformamide and insoluble in water and some other organic solvents. Elemental analysis data, spectroscopic (IR, UV-vis. and florescence), effective magnetic moment in Bohr magnetons and the proton NMR suggest the structures. However, definite particle size is determined by invoking the X-ray powder diffraction and scanning electron microscopy data. The results obtained suggested that pyridoxine reacted with metal ions as a bidentate ligand through its phenolate oxygen and the oxygen of the adjacent group at the 4‧-position. The molar conductance measurements proved that the pyridoxine complexes are electrolytic in nature. The kinetic and thermodynamic parameters such as: Ea, ΔH*, ΔS* and ΔG* were estimated from the DTG curves. The antibacterial evaluation of the pyridoxine and their complexes were also performed against some gram positive, negative bacteria as well as fungi.

  3. Synthesis, spectroscopic and antimicrobial studies of La(III), Ce(III), Sm(III) and Y(III) Metformin HCl chelates

    Science.gov (United States)

    Refat, Moamen S.; Al-Azab, Fathi M.; Al-Maydama, Hussein M. A.; Amin, Ragab R.; Jamil, Yasmin M. S.; Kobeasy, Mohamed I.

    2015-05-01

    Metal complexes of Metformin hydrochloride were prepared using La(III), Ce(III), Sm(III) and Y(III). The resulting complexes were discussed and synthesized to serve as potential insulin-mimetic. Some physical properties and analytical data of the four complexes were checked. The elemental analysis shows that La(III), Ce(III) Sm(III) and Y(III) formed complexes with Metformin in 1:3 (metal:MF) molar ratio. All the synthesized complexes are white and possess high melting points. These complexes are soluble in dimethylsulfoxide and dimethylformamide, partially soluble in hot methanol and insoluble in water and some other organic solvents. From the spectroscopic (infrared, UV-vis and florescence), effective magnetic moment and elemental analyses data, the formula structures are suggested. The results obtained suggested that Metformin reacted with metal ions as a bidentate ligand through its two imino groups. The molar conductance measurements proved that the Metformin complexes are slightly electrolytic in nature. The kinetic thermodynamic parameters such as: E∗, ΔH∗, ΔS∗ and ΔG∗ were estimated from the DTG curves. The antibacterial evaluations of the Metformin and their complexes were also performed against some gram positive, negative bacteria as well as fungi.

  4. Limited infiltration due to reactive sintering of nano-Sm2O3 with preforms—its effect on (Y, Sm)Ba2Cu3O7-δ superconductors

    Science.gov (United States)

    Naik, S. Pavan Kumar; Missak Swarup Raju, P.; Rajasekharan, T.; Bai, V. Seshu

    2016-11-01

    Preform optimized infiltration growth process (POIGP) is employed to fabricate mixed rare earth (Y, Sm)Ba2Cu3O7-δ superconductors of high performance. POIGP creates wide range of pinning centres and also enables nano-particle additions to stable Y2BaCuO5 (Y-211) preforms. Nano-Sm2O3 particles (30-50 nm) were introduced in 0, 10, 20 and 30 wt.%, homogenously and without agglomeration, into the Y-211 preforms and the corresponding composites YBCO-Ar, YSm-10, YSm-20 and YSm-30 are fabricated. Though all the samples were processed in argon atmosphere to suppress the formation of solid solutions with Sm at Ba site, the effort was successful only in the YSm-20 sample, as seen from sharp diamagnetic transition and XRD studies. Magnetic property measurements were carried out on samples which showed strong (00l) texture, but were not necessarily single crystalline since no seed was used in the experiments. The calculated critical current densities (J c) are thus reflective of the values in the basal plane, in the most favourable direction. The final composites revealed YSm-20 to exhibit better J c with substantial flux pinning up to 9 T, at 77 K. Detailed examination of microstructures and field dependence of J c reveal that the addition of nano-particles is not always rewarding and can lead to reactive sintering of Y-211 and limit the extent of liquid phase inflow into preforms. This not only can lead to incomplete reaction leaving larger 211 particles in the matrix, but can also shift the composition of liquid phase such that it promotes the formation of undesired solid solutions in IG processed REBCO as seen in YSm-30. The effect of various factors like open porosity in the preform, the ease of liquid phase infiltration and the liquid phase composition on the residual 211 size in the composites, suppression of RE/Ba solid solutions, and the resultant J c versus H curves is discussed.

  5. Phase Relations in Ba6−3xLn8+2xTi18O54 (Ln = Nd & Sm Electroceramics

    Directory of Open Access Journals (Sweden)

    Amanda L. Snashall

    2013-01-01

    x=0.33, ceramics with high Sm content are found to experience a severe degradation of Qf and changes in τcf trending, associated with the onset of globular and needle-like grain morphology and a Ba-Ti rich phase. x=0.67 ceramics with high Nd content are found to exhibit a secondary phase (Nd2Ti2O7 upon prolonged sintering which resulted in beneficial changes to Qf and τcf without affecting εr. Two BLnTss ceramics compositions with near-zero τcf were successfully synthesised with high Qf and εr values.

  6. Preparation and Electrical Property of Ba1.03Ce0.8Ho0.2O3-α Solid Electrolyte

    Institute of Scientific and Technical Information of China (English)

    WANG, Maoyuan; QIU, Ligan; SUN, Yufeng

    2009-01-01

    Ba1.03Ce0.8Ho0.2O3-α solid electrolyte with nonstoichiometric composition was prepared by high temperature solid-state reaction. Phase composition, surface and fracture morphologies of the material were characterized by using XRD and SEM, respectively. Ionic transport number and conductivity of the material were measured by gas concentration cell and ac impedance spectroscopy methods in the temperature range of 600-1000 ℃ in dry air, wet air and wet hydrogen, respectively. Ionic conduction was researched and compared with those of BaCe0.8Ho0.2O3-α and Ba0.970.8Ho0.2O3-α. The results indicate that Ba1.03Ce0.8Ho0.2O3-α is a single-phase perovskite-type orthorhombic system. In the temperature range of 600-1000 ℃, it is a mixed conductor of oxide ion and electron hole with the oxide ionic transport number of 0.10-0.36 in dry air atmosphere, a mixed conductor of proton, oxide ion and electronic hole with the protonic transport number of 0.11-0.01 and the oxide ionic trans- port number of 0.34-0.30 in wet air atmosphere, and a pure protonic conductor with the protonic transport number ionic conduction is superior to that of BaCe0.8Ho0.2O3-α and Ba0.97Ce0.8Ho0.2O3-α under the experimental conditions.

  7. Y3Al5O12:Re3+ (Re=Ce, Eu, and Sm nanocrystalline powders prepared by modified glycine combustion method

    Directory of Open Access Journals (Sweden)

    Lojpur V.

    2014-01-01

    Full Text Available Yttrium aluminum garnet doped with rare earth ions (Ce3+, Eu3+ and Sm3+ was prepared by modified glycine method. Ce3+ as a dopant was used in four different concentrations (Y3-xCexAl5O12; x(% = 1, 2, 3, 5, while doping concentration of Eu3+ and Sm3+ was Y3-xEuxAl5O12; x(% = 3 and Y3-xSmxAl5O12; x(% = 1, respectively. Phase composition of powders was investigated using XRD technique and expected target phase was confirmed. Photoluminescent characterization included measurements of excitation and emission spectra, as well as determination of emission decays. Y3-xCexAl5O12 shows intense broad-band emission, with maximum in green spectral region, at about 524 nm under ultraviolet or blue excitation. The origin of the luminescence is the 5d1→4f1 transition which is both parity and spin allowed. Ultraviolet and blue excitations of Eu3+ and Sm3+ doped Y3Al5O12 produce intense orange and red emissions. These emissions are phosphorescent in character and come from spin forbidden f-f electron transitions in Eu3+ and Sm3+ ions. For the case of Eu3+ doping emission comes mainly from 5D0→7F1 transitions with Stark components peaking at 590 nm and 590.75 nm, and with emission decay of 4.15 ms. In the case of Sm3+ doping, the emission spectrum, shows 4G5/2→6H5/2, 4G5/2→6H7/2, and 4G5/2→6H9/2 transitions, with the most intense stark components positioned at 567.5 nm, 617 nm, and 650 nm, respectively and for transition centered at 617 nm, emission decay is 3.12 ms. [Projekat Ministarstva nauke Republike Srbije, br. 171022 i br. 45012

  8. Vacuum ultraviolet-ultraviolet and x-ray excited luminescence properties of Ba3Gd(BO3)3:Ce3+

    NARCIS (Netherlands)

    Han, B.; Liang, H.; Lin, H.; Zhong, J.; Su, Q.; Dorenbos, P.; Birowosuto, M.D.; Zhang, G.; Fu, Y.

    2007-01-01

    The phosphors Ba3Gd(BO3)3:Ce3+ were prepared by a solid-state reaction technique at high temperature. The vacuum ultraviolet-ultraviolet and visible spectroscopic properties of the phosphors together with decay time curves are investigated and discussed. The spectroscopic properties are explained by

  9. Sm-doped CeO{sub 2} single buffer layer for YBCO coated conductors by polymer assisted chemical solution deposition (PACSD) method

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Pu, M.H.; Sun, R.P.; Wang, W.T.; Wu, W.; Zhang, X.; Yang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)], E-mail: yzhao@home.swjtu.edu.cn

    2008-10-20

    An over 150 nm thick Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} (SCO) single buffer layer has been deposited on bi-axially textured NiW (2 0 0) alloy substrate. Highly in-plane and out-of-plane oriented, dense, smooth and crack free SCO single layer has been obtained via a polymer-assisted chemical solution deposition (PACSD) approach. YBCO thin film has been deposited equally via a PACSD route on the SCO-buffered NiW, the as grown YBCO yielding a sharp transition at T{sub c0} = 87 K as well as J{sub c}(0 T, 77 K) {approx} 1 MA/cm{sup 2}. These results indicates that RE (lanthanides other than Ce) doping may be an effective approach to improve the critical thickness of solution derived CeO{sub 2} film, which renders it a promising candidate as single buffer layer for YBCO coated conductors.

  10. Structural and {sup 121}Sb Moessbauer spectroscopic investigations of the antimonide oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr)

    Energy Technology Data Exchange (ETDEWEB)

    Schellenberg, I.; Nilges, T.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2008-07-15

    Quaternary antimonide oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr) were synthesized from the RESb monoantimonides and MnO, respectively ZnO, in sealed tubes at 1170 K. Single crystals were obtained from NaCl/KCl salt fluxes. The ZrCuSiAs-type (space group P4/nmm) structures of LaMnSbO (a = 423.95(7), c = 955.5(27) pm, wR2 = 0.067, 247 F{sup 2}), CeMnSbO (a = 420.8(1), c = 950.7(1) pm, wR2 = 0.097, 250 F{sup 2}), SmMnSbO (a = 413.1(1), c = 942.3(1) pm, wR2 = 0.068, 330 F{sup 2}), LaZnSbO (a = 422.67(6), c = 953.8(2) pm, wR2 = 0.052, 259 F{sup 2}), and NdZnSbO (a = 415.9(1), c = 945.4(4) pm, wR2 = 0.109, 206 F{sup 2}) were refined from single crystal X-ray diffractometer data. The structures consist of covalently bonded (RE{sup 3+}O{sup 2-}){sup +} and (T{sup 2+}Sb{sup 3-}){sup -} layers with weak ionic interlayer interactions. The oxygen and transition metal atoms both have tetrahedral coordination within the layers. {sup 121}Sb Moessbauer spectra of the REMnSbO and REZnSbO compounds show single antimony sites with isomer shifts close to -8 mm s{sup -1}, in agreement with the antimonide character of these compounds. PrMnSbO and NdMnSbO show transferred hyperfine fields of 8 T at 4.2 K. (orig.)

  11. Study on package of white led device for ce,sm:yag single crystal%Ce,Sm:YAG单晶用于白光LED器件的封装研究

    Institute of Scientific and Technical Information of China (English)

    郝继彦; 陈兆平; 张成龙; 向卫东; 刘海涛

    2015-01-01

    采用提拉法生长了白光LED用Ce,Sm:YAG单晶,用XRD对物相进行分析,探讨了不同因素对LED器件光电参数的影响,采用LED老化仪对不同封装形式的LED器件进行了光衰测试,结果表明:采用不同支架封装对LED器件光电参数影响很小;提高晶片厚度可以增加光效,但光谱中黄绿光成分随之增加,色度坐标偏离白光区域;随着测试电流的降低,器件光效显著增加,AB胶的引入可以增加器件的光效。而在1000小时光衰测试中并未出现发光衰减。%Ce,Sm:YAG single crystal for white light emitting diode (LED) was grown by Czochralski method. The crystal phase structure of YAG was analysised by XRD.The photoelectric properties of white LED fabricated by Ce,Sm:YAG single crystal Were also measured by several factors.The light decay of LED device was tested by the LED aging instrument.LED packages of different stents optical parameters of the device have little effect.Thickness of the wafer can be increased to improve light efficiency, but increases the spectral components in yellow-green,white chromaticity coordinates deviate from the region.With lower test current,there is significant increasing in device efficiency.The introducing of AB glue can increase the optical efficiency of the device.There was no luminescence decay during the test of 1000 h.

  12. Pencil Beam Spectral Measurements of Ce, Ho, Yb, and Ba Powders for Potential Use in Medical Applications

    Directory of Open Access Journals (Sweden)

    N. Martini

    2015-01-01

    Full Text Available The aim of the present study was to obtain modified X-ray spectra, by using appropriate filter materials for use in applications such as dual energy X-ray imaging. K-edge filtering technique was implemented in order to obtain narrow energy bands for both dual- and single-kVp techniques. Three lanthanide filters (cerium, holmium, and ytterbium and a filter outside lanthanides (barium, with low K-edge, were used to modify the X-ray spectra. The X-ray energies that were used in this work ranged from 60 to 100 kVp. Relative root mean square error (RMSE and the coefficient of variation were used for filter selection. The increasing filter thicknesses led to narrower energy bands. For the dual-kVp technique, 0.7916 g/cm2 Ho, 0.9422 g/cm2 Yb, and 1.0095 g/cm2 Yb were selected for 70, 80, and 90 kVp, respectively. For the single-kVp technique 0.5991 g/cm2 Ce, 0.8750 g/cm2 Ba, and 0.8654 g/cm2 Ce were selected for 80, 90, and 100 kVp, respectively. The filtered X-ray spectra of this work, after appropriate modification, could be used in various X-ray applications, such as dual-energy mammography, bone absorptiometry, and digital tomosynthesis.

  13. Ultra-large current transport in thick SmBa2Cu3O7−x films grown by reactive co-evaporation

    International Nuclear Information System (INIS)

    Highlights: • Transport properties of 5 μm thick SmBa2Cu3O7−x thin films were investigated. • Laser scanning microscopy was used to demonstrate local transport properties. • Temperature variable laser scanning microscopy shows correlation between structural and transport properties. • Optical measurements described nature of current transport properties in the coated conductors. - Abstract: Structural and transport properties of high performance SmBa2Cu3O7−x coated conductors produced by a dual-chamber co-evaporation are presented. The 5 μm-thick SmBCO coated conductors grown on IBAD-MgO based Hastelloy metal templates show critical currents larger than 1020–1560 A/cm at 77 K and self-field. The current transport characteristics of the conductors are investigated by room-temperature thermoelectric microscopy and low-temperature bolometric microscopy. The local thermoelectric images show the tilted grains, grain boundaries, and microstructural defects on the surface of the coated conductors. The bias current-dependent bolometric response at low temperature displays the current of the local flux flow dissipation as an increasing bias. Furthermore, we measured micro-Raman scattering microscopic imaging on oxygen-related peaks of the conductors. Comparing the Raman signal images with the low temperature optical scanning maps, it is remarkable that the structural disorders represented by oxygen-related Raman peaks are closely related to the low temperature bolometric abnormalities. From this result, a nature of the dissipative current distribution in coated conductors is revealed. The scanning optical microscopic study will provide a promising method for quality assurance of coated conductors

  14. Clarification and mitigation of marked J c decrease at low magnetic fields of BaHfO3-doped SmBaCuO3 thin films deposited on seed layer

    Science.gov (United States)

    Watanabe, Yutaro; Ichino, Yusuke; Yoshida, Yutaka; Ichinose, Ataru

    2016-07-01

    In accordance with the results of our previous research, a low-temperature growth (LTG) technique is effective for expanding the lower growth temperature region of c-axis-orientated SmBa2Cu3O y (SmBCO) thin films. However, BaHfO3 (BHO)-doped LTG films show a marked decrease in J c at low magnetic fields compared with conventional PLD films. In this study, we aimed to clarify the mechanism of J c decrease and investigated the thickness dependence of the seed layer on the (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) (100) single crystal. The obtained results indicate that J c decreased at low magnetic fields as the thickness of the seed layer increased. It is suggested that flux line kinks produced by flux motion in the seed layer would lead to the depinning of flux lines from BHO nanorods in the upper layer. Thus, we added Y2O3 into the seed layer to trap flux lines in the seed layer. Consequently, we improved J c in the low magnetic field region even in the films prepared by using the LTG technique.

  15. Study of Sm0.2Ce0.8O1.9 (SDC) electrolyte prepared by a simple modified solid-state method

    Institute of Scientific and Technical Information of China (English)

    殷仕龙; 李梦楠; 曾燕伟; 李传明; 陈小卫; 叶祝鹏

    2014-01-01

    Sm0.2Ce0.8O1.9 (SDC) electrolyte was prepared by a modified solid state method at relatively low sintering temperatures without any sintering promoters. The phase composition and microstructure of the electrolytes were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) technologies. A relative density of SDC electrolyte sintered at 1300 ºC reached 97.3%and the mean SDC grain size was about 770 nm. Their ionic conductivity and thermal expansion coefficient were also measured by electrochemical workstation and dilatometer. The electrolyte attained a high conductivity of 5×10-2 S/cm at 800 ºC with an activation energy of 1.03 eV and a proper thermal expansion coefficient of 12.6×10-6 K-1.

  16. Synthesis, thermal and spectroscopic behaviors of metal-drug complexes: La(III), Ce(III), Sm(III) and Y(III) amoxicillin trihydrate antibiotic drug complexes

    Science.gov (United States)

    Refat, Moamen S.; Al-Maydama, Hussein M. A.; Al-Azab, Fathi M.; Amin, Ragab R.; Jamil, Yasmin M. S.

    2014-07-01

    The metal complexes of Amoxicillin trihydrate with La(III), Ce(III), Sm(III) and Y(III) are synthesized with 1:1 (metal:Amox) molar ratio. The suggested formula structures of the complexes are based on the results of the elemental analyses, molar conductivity, (infrared, UV-visible and fluorescence) spectra, effective magnetic moment in Bohr magnetons, as well as the thermal analysis (TG), and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results obtained suggested that Amoxicillin reacted with metal ions as tridentate ligands, coordinating the metal ion through its amino, imino, and β-lactamic carbonyl. The kinetic thermodynamic parameters such as: Ea, ΔH*, ΔS* and ΔG* were estimated from the DTG curves.

  17. Thermopower, Hall effect and magnetoresistivity of Ru 1- xSb xSr 2Sm 1.5Ce 0.5Cu 2O 10- d

    Science.gov (United States)

    Ilonca, G.; Patapis, S.; Beiusan, F.; Lung, C.; Toma, V.; Balint, P.; Bodea, M.; Jurcut, T.

    2007-09-01

    Magnetoresistivity, thermopower and Hall effect on the samples of Ru1-xSbxSr2Sm1.5Ce0.5Cu2O10-d were investigated in the temperature range 4-300 K with a magnetic field up to 9 T. Superconducting transition temperature decreases with increases content of Sb, due to a distortion of RuO6 octahedral, which is responsible of the increase in hole localization, reflected by Hall concentration, too. The inhomogeneous granular structure is put in evidence by the intragranular, Tco, and intergranular Tcg, transition temperatures. Hall effect and thermopower anomalous decreases below Tmagnetic can be explained within a simple two-band model by a transition from localized to more itinerant behavior in the RuO2 layer at Tmagnetic.

  18. Crystal structures of the R{sub 2}CuInS{sub 5} (R=La, Ce, Pr, Nd and Sm) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Huch, M.R. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave. 13, Lutsk 43009 (Ukraine); Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave. 13, Lutsk 43009 (Ukraine)]. E-mail: gulay@univer.lutsk.ua; Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave. 13, Lutsk 43009 (Ukraine); Pietraszko, A. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna str. 2, P.O. Box 1410, Wroclaw 50-950 (Poland)

    2006-11-30

    The crystal structures of the R{sub 2}CuInS{sub 5} (R = La, Ce, Pr, Nd, Sm) compounds (space group Pnma, Pearson symbol oP36) were determined by means of X-ray single crystal diffraction (a = 1.1487(2) nm, b = 0.39760(8) nm, c 1.6911(3) nm, R1 = 0.0250 for La{sub 2}CuInS{sub 5}) and X-ray powder diffraction (a 1.14396(7) nm, b = 0.39361(2) nm, c = 1.6804(1) nm, R {sub Bragg} = 0.0937 for Ce{sub 2}CuInS{sub 5}; a = 1.14123(6) nm, b = 0.39119(2) nm, c = 1.6737(1) nm, R {sub Bragg} = 0.0974 for Pr{sub 2}CuInS{sub 5}; a = 1.13948(6) nm, b = 0.38933(2) nm, c = 1.66886(9) nm, R {sub Bragg} = 0.0853 for Nd{sub 2}CuInS{sub 5}; a = 1.13671(7) nm, b = 0.38594(2) nm, c = 1.6603(1) nm, R {sub Bragg} = 0.0887 for Sm{sub 2}CuInS{sub 5}). The R-centered trigonal prisms, Cu-centered tetrahedra and In-centered octahedra can be selected in the crystal structures of the R{sub 2}CuInS{sub 5} compounds.

  19. Crystal structures of the R{sub 3}CuSnSe{sub 7} (R = La, Ce, Pr, Nd, Sm, Gd, Tb and Dy) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine)]. E-mail: gulay@lab.univer.lutsk.ua; Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine)

    2005-02-22

    The crystal structures of the R{sub 3}CuSnSe{sub 7} (R = La, Ce, Pr, Nd, Sm, Gd, Tb and Dy) compounds (La{sub 3}CuSiS{sub 7} structure type, space group P6{sub 3}, Pearson symbol hP24) were determined by means of X-ray powder diffraction: a 1.07211(1) nm, c = 0.62770(1) nm, R{sub I} = 0.0613 (La{sub 3}CuSnSe{sub 7}); a = 1.06310(2) nm, c = 0.62562(1) nm, R{sub I} = 0.0737 (Ce{sub 3}CuSnSe{sub 7}); a = 1.05613(4) nm, c 0.62532(3) nm, R{sub I} = 0.0964 (Pr{sub 3}CuSnSe{sub 7}); a = 1.05002(4) nm, c = 0.62523(2) nm, R{sub I} = 0.0808 (Nd{sub 3}CuSnSe{sub 7}); a = 1.03809(2) nm, c = 0.62848(2) nm, R{sub I} 0.0745 (Sm{sub 3}CuSnSe{sub 7}); a = 1.02435(2) nm, c = 0.63409(2) nm, R{sub I} = 0.0834 (Gd{sub 3}CuSnSe{sub 7}); a = 1.01894(2) nm, c = 0.63642(2) nm, R{sub I} = 0.0881 (Tb{sub 3}CuSnSe{sub 7}); a = 1.01359(3) nm, c = 0.63809(3) nm, R{sub I} = 0.0916 (Dy{sub 3}CuSnSe{sub 7})

  20. Crystal structures of the R{sub 3}CuGeSe{sub 7} (R = Ce, Pr, Nd, Sm, Gd, Tb and Ho) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine)]. E-mail: gulay@univer.lutsk.ua; Lychmanyuk, O.S. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine); Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine); Pietraszko, A. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna str. 2, P.O. Box 1410, 50-950 Wroclaw (Poland)

    2006-09-28

    The crystal structures of the R{sub 3}CuGeSe{sub 7} compounds (R = Ce, Pr, Nd, Sm, Gd, Tb and Ho) (La{sub 3}CuSiS{sub 7} structure type, space group P6{sub 3}, Pearson symbol hP24) were determined by means of X-ray single crystal diffraction (a 1.0643(1) nm, c = 0.60973(7) nm, R1 = 0.0269 for Ce{sub 3}CuGeSe{sub 7}; a = 1.0559(1) nm, c = 0.6084(1) nm, R1 = 0.0301 for Pr{sub 3}CuGeSe{sub 7}; a = 1.0519(1) nm, c 0.60707(9) nm, R1 = 0.0305 for Nd{sub 3}CuGeSe{sub 7}) and X-ray powder diffraction (a = 1.04216(3) nm, c = 0.60447(3) nm, R {sub Bragg} = 0.0862 for Sm{sub 3}CuGeSe{sub 7}; a = 1.03491(8) nm, c = 0.60395(7) nm, R {sub Bragg} = 0.0932 for Gd{sub 3}CuGeSe{sub 7}; a = 1.02940(5) nm, c = 0.60387(4) nm, R {sub Bragg} = 0.0734 for Tb{sub 3}CuGeSe{sub 7}; a = 1.01978(7) nm, c = 0.60612(6) nm for Ho{sub 3}CuGeSe{sub 7}). The R atoms are surrounded by distorted trigonal prisms. A triangular surrounding exists for the Cu atoms. A tetrahedral surrounding exists for the Ge atoms.

  1. Synthesis, vacuum ultraviolet and ultraviolet spectroscopy of Ce{sup 3+} ion doped olgite Na(Sr, Ba)PO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Huang Yanlin [School of Material Engineering, Soochow University, 178 GanJiang East Road, Suzhou, 215021 (China); Wang Xigang [School of Material Engineering, Soochow University, 178 GanJiang East Road, Suzhou, 215021 (China); Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Cho, Eunjin [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Jang, Kiwan [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Tao Ye [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2007-12-21

    Ce{sup 3+} ion doped olgite mineral samples, Na(Sr, Ba)PO{sub 4}, were prepared by a high temperature solid-state reaction. The sample was investigated through x-ray powder diffraction, FT-IR and FT-Raman spectra measurements. The optical properties under vacuum ultraviolet (VUV) synchrotron radiation and ultraviolet (UV) irradiation are reported for the first time. The investigated samples show a strong absorption in the VUV and UV ranges. The bands corresponding to the 4f{sup 1} {yields} 4f{sup 0}5d{sup 1} transitions of Ce{sup 3+} ions in the host lattices are identified. The barycentre of Ce{sup 3+} ions in the host lattices, the host absorption, the crystal field splitting, the emission and the Stokes shifts are presented and discussed. This Ce{sup 3+} ion doped material is a potential candidate for plasma display panel (PDP) application.

  2. Preliminary Study on Hydrogen Permeation and Stability of BaCe0.90Y0.10O3-δ Membrane under Asymmetric Atm osphere

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@High-temperature proton conductors (HTPC) have been extensively studied since I wahara et al?1? reported protonic conduction in SrCeO3-based oxid es. Later, the BaCeO3-based oxides, such as BaCe0.90Yb0.10O3- d (BCYb10) and BaCe0.90Y0.10-O3-d (BCY10), we re fou nd to show higher conductivity?2?. High electronic and protonic conducti vity makes BCY10 a potential membrane for hydrogen separation?3?. Thin f ilms with high density, most probably made by sequential coating on porous subst rates, are imperative in order to promote hydrogen permeation flux?4?. T his makes it more necessary for such membranes to be kept stable and unspoilt un der asymmetric hydrogen-permeation atmosphere at elevated temperatures. In this paper, the stability and hydrogen permeation ability of BCY10 membrane are stud ied by XRD, SEM, energy dispersive X-ray (EDX) analysis, H2-TPR process and hydrogen permeation experiment. The results showed that hydrogen cannot permeate through the BCY10 membrane without surface modification, and its surface cannot keep a uniform perovskite structure in the asymmetric atmosphere.

  3. Photoluminescence and Energy Transfer Properties with Y+SiO4 Substituting Ba+PO4 in Ba3Y(PO4)3:Ce(3+)/Tb(3+), Tb(3+)/Eu(3+) Phosphors for w-LEDs.

    Science.gov (United States)

    Li, Kai; Liang, Sisi; Shang, Mengmeng; Lian, Hongzhou; Lin, Jun

    2016-08-01

    A series of Ce(3+), Tb(3+), Eu(3+) doped Ba2Y2(PO4)2(SiO4) (BYSPO) phosphors were synthesized via the high-temperature solid-state reaction route. X-ray diffraction, high-resolution transmission electron microscopy, Fourier transform infrared, solid-state NMR, photoluminescence (PL) including temperature-dependent PL, and fluorescent decay measurements were conducted to characterize and analyze as-prepared samples. BYSPO was obtained by the substitution of Y+SiO4 for Ba+PO4 in Ba3Y(PO4)3 (BYPO). The red shift of PL emission from 375 to 401 nm occurs by comparing BYSPO:0.14Ce(3+) with BYPO:0.14Ce(3+) under 323 nm UV excitation. More importantly, the excitation edge can be extended from 350 to 400 nm, which makes it be excited by UV/n-UV chips (330-410 nm). Tunable emission color from blue to green can be observed under 365 nm UV excitation based on the energy transfer from Ce(3+) to Tb(3+) ions after codoping Tb(3+) into BYSPO:0.14Ce(3+). Moreover, energy transfer from Tb(3+) to Eu(3+) ions also can be found in BYSPO:Tb(3+),Eu(3+) phosphors, resulting in the tunable color from green to orange red upon 377 nm UV excitation. Energy transfer properties were demonstrated by overlap of excitation spectra, variations of emission spectra, and decay times. In addition, energy transfer mechanisms from Ce(3+) to Tb(3+) and Tb(3+) to Eu(3+) in BYSPO were also discussed in detail. Quantum yields and CIE chromatic coordinates were also presented. Generally, the results suggest their potential applications in UV/n-UV pumped LEDs. PMID:27415966

  4. Scintillation characteristics of nonstoichiometric phases formed in MF sub 2 -GdF sub 3 -CeF sub 3 system Part II. (M=Ba), scintillation of Ba sub 1 sub - sub x Ce sub x F sub 2 sub + sub x (0.1<=x<=0.45) fluorite type crystals

    CERN Document Server

    Kobayashi, M; Sobolev, B P; Zhmurova, Z I; Krivandina, E A

    1999-01-01

    Among three different Ce-concentrations (10, 27 and 45 mol%) which we tested, the 27 mol% sample showed by far the best radiation hardness and the maximum fast component fraction in the luminescence. For this Ce-concentration, the scintillation intensity was about 30% of that in pure BaF sub 2 (within a 1 mu s gate) and comparable to that in CeF sub 3. The decay constant of scintillation was about 38 ns. The melting curve of the Ba sub 1 sub - sub x Ce sub x F sub 2 sub + sub x solid solutions has a maximum at approximately 27 mol% CeF sub 3. The congruent character of the melt with this composition, which should be related with specific structural defects configuration in anionic sublattice, could be the reason for the excellent radiation hardness observed in the Ba sub 0 sub . sub 7 sub 3 Ce sub 0 sub . sub 2 sub 7 F sub 2 sub . sub 2 sub 7 crystal.

  5. Synthesis, characterization and TL response of Ce{sup 3+} activated BaMgAl{sub 10}O{sub 17} phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Selot, Anupam, E-mail: selotanupam14@rediffmail.com [Department of Physics, Sadhu Vaswani College, Bhopal-462030 (India); Aynyas, Mahendra [Department of Physics, C.S.A. Govt P. G. College, Sehore-466001 (India); Tiwari, Manoj [Department of Physics, MPIET, Gondia - 441614 (India); Dev, Kapil [Department of Physics, RITS, Bhopal - 462016 (India)

    2015-06-24

    Phosphor material BaMgAl{sub 10}O{sub 17} with varying concentration of rare earth Ce{sup 3+} synthesis by combustion method at 500°C. The synthesized phosphor material characterized for their crystallinity and nature by XRD measurements. The thermoluminescecne response of phosphor exhibit TL spectra at 204°c and detailed analysis of kinetic parameter by de convoluted curve. These results show that concentration quenching occur at 5mol% of Ce dopant. The results suggest the possibility of utilizing as a phosphor may be in UV dosimeter and solid state lighting.

  6. Quantitative description of the phase transition of Aurivillius oxides Sm modified BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Pinyang, E-mail: fpy_2000@163.com [College of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Shaanxi Key Laboratory of Photoelectric Functional Materials and Devices, School of Materials and Chemical Engineering, Xi' an Technological University, Xi' an 710032 (China); Liu, Peng [College of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Xi, Zengzhe [Shaanxi Key Laboratory of Photoelectric Functional Materials and Devices, School of Materials and Chemical Engineering, Xi' an Technological University, Xi' an 710032 (China)

    2015-07-15

    BaBi{sub 4}Ti{sub 4}O{sub 15}+xwt.%Sm{sub 2}O{sub 3} (x=0.00, 0.25, 0.50, 0.75) ceramics were prepared by the solid-state reaction method. The effect of samarium additives on the structural and electrical properties of BBT ceramic was investigated. XRD patterns indicate that all ceramics are an m=4 members of Aurivillius oxides and no secondary phases were detected. A broad dielectric peak in frequency dependent dielectric spectrum is observed during the phase transition of all the BBT ceramics. The modified Curie–Weiss law, Vogel–Fucher relationship and Lorentz-type law were used to describe the phase transition behavior. The relaxor behavior was described well by the modified Curie–Weiss law and Vogel–Fucher relation. The effect of samarium additives on the degree of relaxation and diffuseness of BBT ceramics was discussed.

  7. Microwave dielectric properties and microstructure of Ba2-xSm4+2x/3Ti8+yO24+2y ceramics

    International Nuclear Information System (INIS)

    The microstructure and microwave dielectric properties of barium samarium titanium oxide Ba2-xSm4+2x/3Ti8+yO24+2y (x=0.1, y=0∼2) ceramics (BST) were investigated. The optimum compositions of BST ceramics were synthesized and discussed base on the structure formula of the tungsten-bronze-type crystal phase. Differential thermal analysis (DTA) was used to select the suitable sintering temperatures. The relative dielectric constant of the BST compositions saturated in a range from 63 to 85. Qxf values of 8500-13000 (GHz) were obtained for various y values in dense samples. The temperature coefficient of resonant frequency τf was adjusted from a negative -12 ppm per deg. C value to a positive value 17 ppm per deg. C. X-ray diffraction, SEM and EDS analysis were used to investigate the microstructure and correlate its relationship with microwave dielectric properties of BST ceramics

  8. Charge/orbital ordering structure in ordered perovskite Sm sub 1 sub / sub 2 Ba sub 1 sub / sub 2 MnO sub 3

    CERN Document Server

    Uchida, M; Akahoshi, D; Kumai, R; Tomioka, Y; Tokura, Y; Arima, T H

    2002-01-01

    In an A-site ordered perovskite manganite Sm sub 1 sub / sub 2 Ba sub 1 sub / sub 2 MnO sub 3 , a new charge/orbital ordering pattern was found at room temperature. Electron diffraction studies revealed a series of superlattice reflections with modulation vectors at q sub 2 =(1/2, 1/2, 1/2) as well as at q sub 1 =(1/4, 1/4, 0) in the tetragonal setting (a sub p x a sub p x 2a sub p , a sub p being the cubic perovskite lattice parameter). Together with the results of the resonant X-ray scattering and the charge-transport and magnetization measurements, a new model for the three-dimensional charge/orbital ordering in the ordered perovskite is proposed. (author)

  9. Mixed Conduction in Tb2O3 Doped BaCeO3

    Institute of Scientific and Technical Information of China (English)

    QIU Li-Gana; MA Gui-Lin

    2006-01-01

    BaxCe0.8Tb0.2O3-α (x=0.98-1.03) solid electrolytes were synthesized and characterized by using X-ray diffraction (XRD). By using AC impedance spectroscopy and gas concentration cell electromotive force (EMF) measurements, the electrical conduction behavior of the specimens was investigated in different gases during 500-1000 ℃.The influence of nonstoichiometry in the specimens with x≠ 1 on conduction properties was studied and comparedwith that in the specimen with x= 1. The results show that the specimens are all of perovskite-type orthorhombic structure. In 500-1000 ℃, electronic hole conduction is dominant in dry and wet oxygen, air or nitrogen. Protonic conduction is dominant in wet hydrogen and it is about two orders of magnitude higher than that in hydrogen-free atmospheres (oxygen, air and nitrogen). The electrical conductivity of the same specimen in water apor-saturated oxygen, air or nitrogen is slightly higher than that in corresponding gas without water vapor. The electrical conductivities of the nonstoichiometric specimens are higher than those of the stoichiometric one.

  10. Preparation and third-order nonlinear optical properties of self-organized complex oxide Ce:BaTiO3 quantum dots

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Pulsed laser ablation epitaxial Strancky-Krastanow growth of self-organized complex oxide Ce:BaTiO3 quantum dots on MgO(100) substrates is demonstrated.Atomic force microscopy and X-ray diffraction are used to observe the structure and the growth process of the self-organized complex oxide quantum dots.The average dimension,height,and the density of self-organized complex oxide Ce:BaTiO3 quantum dots are given.The nonlinear refractive indexes of the wetting layer and the self-organized ordered quantum dots are determined by the single beam Z-scan method.The mechanisms of the nonlinear effect enhancement for these low-dimensional structure are discussed.

  11. Behavior of BaCe0.9−x Zrx Y0.1O3−δ in water and ethanol suspensions

    DEFF Research Database (Denmark)

    Della Negra, Michela; Zhang, Wei; Bonanos, Nikolaos;

    2014-01-01

    The stability of perovskite proton conductors BaCe0.2Zr0.7Y0.1O2.95 and BaCe0.5Zr0.4Y0.1O2.95 (referred to as BCZY) has been tested by exposure of powders to water and ethanol at room temperature. The liquid phase was monitored as a function of time with inductively coupled plasma-optical emission...... electron microscopy (TEM). TEM confirmed the degradation of the perovskite phase and revealed barium carbonate nanobranches and nanoparticles from the agglomeration of the fragmented perovskite. The effect of ethanol was much less severe; leaching of elements after immersion was negligible for up to 17...... days, and XRD patterns before and after treatment did not show any structural degradation. It is concluded that ethanol is an appropriate choice as a processing solvent for tapecasting BCZY powders....

  12. Synthesis and characterization of BaCe0.8Y0.2O2.9 nanopowder by sol-gel auto-ignited method

    International Nuclear Information System (INIS)

    A sol-gel auto-ignited synthesis, which is a hybrid of sol-gel and auto-ignited techniques, was applied to preparation of homogeneous and stoichiometric BaCe0.8Y0.2O2.9 nanocrystalline ceramic powder as solid electrolyte used in solid oxide fuel cells at 1000 C. Optimal pH value for the mixed citrate-nitrate solutions was determined by calculation. The DTA-TG and XRD were used to investigate the thermal decomposition of the gel precursor. The structure and phase present of the nanocrystalline BaCe0.8Y0.2O2.9 powders were characterized by XRD, BET and SEM techniques. (orig.)

  13. Preparation and third-order nonlinear optical properties of self-organized complex oxide Ce: BaTiO3 quantum dots

    Institute of Scientific and Technical Information of China (English)

    师文生; 陈正豪; 刘宁宁; 吕惠宾; 周岳亮; 崔大复; 杨国桢

    2000-01-01

    Pulsed laser ablation epitaxial Strancky-Krastanow growth of self-organized complex oxide Ce:BaTiO3 quantum dots on MgO(100) substrates is demonstrated. Atomic force microscopy and X-ray diffraction are used to observe the structure and the growth process of the self-organized complex oxide quantum dots. The average dimension, height, and the density of self-organized complex oxide Ce:BaTiO3 quantum dots are given. The nonlinear refractive indexes of the wetting layer and the self-organized ordered quantum dots are determined by the single beam Z-scan method. The mechanisms of the nonlinear effect enhancement for these low-dimensional structure are discussed.

  14. Composite Fe - BaCe0.2Zr0.6Y0.2O2.9 Anodes for Proton Conductor Fuel Cells

    DEFF Research Database (Denmark)

    Lapina, Alberto; Chatzichristodoulou, Christodoulos; Holtappels, Peter;

    2014-01-01

    Symmetrical cells with Fe - BaCe0.2Zr0.6Y0.2O2.9 composite electrodes are produced by screen printing and infiltration, using BaCe0.2Zr0.6Y0.2O2.9 as electrolyte. The electrochemical performance of the composite electrode is studied by impedance spectroscopy at 250–500◦C in dry and wet hydrogen....../nitrogen mixtures. The polarization resistance is 1.6 _ cm2 at 500◦C in wet H2 (pH2O = 0.01 atm), and has an activation energy of 0.72 eV. The cells degrade upon exposure to temperatures up to 500◦C, likely due to coarsening of the iron nanoparticles and loss of electronic percolation in the composite anode. Iron...

  15. Hole-doping effect on the Verwey-type transition and magnetoresistivity of Ba(Sm,Ca)Fe 2O 5+ δ

    Science.gov (United States)

    Nakamura, J.; Lindén, J.; Yamauchi, H.; Karppinen, M.

    2002-02-01

    Two series of samples of the oxygen-deficient double-perovskite phase, Ba(Sm,Ca)Fe 2O 5+ δ were synthesized employing a sample encapsulation technique that utilizes Fe metal as an oxygen getter. The hole-doping level on the FeO 2 plane was controlled by varying the amount of excess oxygen or the Ca concentration at the Sm site. Earlier it had been found that at room temperature five-coordinated Fe 2+ and Fe 3+ species form pairs by sharing a d electron, leading to the formation of a Fe 2.5+ fluctuating valence state [Phys. Rev. B 60 (1999) 15,251]. At TV, a Verwey-type transition occurred, signifying the charge separation of the Fe 2.5+ fluctuating valence state into high-spin Fe 2+ and Fe 3+. Moreover, related to the Verwey-type transition a negative magnetoresistance peak with a magnitude of a few percent was observed [Appl. Phys. Lett. 77 (2000) 1683]. The position of the peak was found to correspond to the jumps seen in the susceptibility and resistivity vs. temperature curves. For the present samples, it is found that the value of TV is severely decreased upon increasing the Ca concentration, as seen by susceptibility and magnetoresistivity measurements. Introduction of excess oxygen leads to a less severe decrease of the transition temperature. The observed behavior of TV was reproduced by a simple model based on combinatorial-entropy calculations.

  16. Scintillation characteristics of nonstoichiometric phases formed in MF sub 2 -GdF sub 3 -CeF sub 3 system Part I. (M=Ba), scintillation of Ba sub 0 sub . sub 9 Gd sub 0 sub . sub 1 sub - sub x Ce sub x F sub 2 sub . sub 1 (0<=x<=0.1) fluorite-type crystals

    CERN Document Server

    Kobayashi, M; Sobolev, B P; Zhmurova, Z I; Krivandina, E A

    1999-01-01

    As the Ce concentration (x) was increased from 0 to 0.1 (complete replacement of Gd), the emission peak wavelength shifted from 310 (due to Gd sup 3 sup + emission) to 350 nm (due to Ce sup 3 sup + emission). The light intensity increased from a few percent to 46% of that in BaF sub 2. The decay constant of the dominant emission approached 30-40 ns, which is characteristic of the Ce sup 3 sup + luminescence. Although the radiation damage increased, its spontaneous recovery also increased by Ce sup 3 sup + doping. Phosphorescence (very slow component), which was significant for x=0 (Ce-undoped), was hardly detectable for x>0.05.

  17. Crystal structure and magnetic properties of R{sub 3}Co{sub 0.5}GeS{sub 7} (R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) and R{sub 3}Ni{sub 0.5}GeS{sub 7} (R = Y, Ce, Sm, Gd, Tb, Dy, Ho, Er and Tm)

    Energy Technology Data Exchange (ETDEWEB)

    Daszkiewicz, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław (Poland); Pashynska, Yu.O. [Department of Material Science, Lutsk National Technical University, L' vivska str. 75, 43018 Lutsk (Ukraine); Marchuk, O.V. [Department of Inorganic and Physical Chemistry, Eastern European National University, Voli Ave 13, 43009 Lutsk (Ukraine); Gulay, L.D. [Department of Ecology and Protection of Environment, Eastern European National University, Voli Ave 13, 43009 Lutsk (Ukraine); Kaczorowski, D., E-mail: D.Kaczorowski@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław (Poland)

    2015-10-25

    The crystal structure of quaternary compounds R{sub 3}Co{sub 0.5}GeS{sub 7} (R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) and R{sub 3}Ni{sub 0.5}GeS{sub 7} (R = Y, Ce, Sm, Gd, Tb, Dy, Ho, Er and Tm) (La{sub 3}Mn{sub 0.5}SiS{sub 7} structure type, space group P6{sub 3}, Pearson symbol hP23) was determined by means of X-ray single crystal diffraction. The R atoms are located in trigonal prisms with two additional atoms, the Co (Ni) atoms occupy octahedra, the Ge atoms are located in tetrahedra. Magnetic properties of the compounds R{sub 3}Co{sub 0.5}GeS{sub 7} (R = Sm and Gd) and R{sub 3}Ni{sub 0.5}GeS{sub 7} (R = Gd, Dy, Er and Tm) were studied down to 1.72 K. Their magnetic behaviour is governed by trivalent rare-earth and divalent transition-metal constituents. In each material, the magnetic exchange interactions are dominated by antiferromagnetic correlations, which promote long-range magnetic orderings at low temperatures. - Highlights: • Identification of several novel R3Co0.5GeS7 and R3Ni0.5GeS7 compounds. • Refinement of their crystal structures from single crystal XRD data. • Determination of magnetic behaviour in a few representative phases.

  18. Investigation into the Incorporation of Phosphate into BaCe1−yAyO3−y/2 (A = Y, Yb, In

    Directory of Open Access Journals (Sweden)

    Alaric D. Smith

    2014-01-01

    Full Text Available In this paper we examine the effect of doping phosphate into BaCe1−yAyO3−y/2 (A = Y, Yb, In. The samples were analysed through a combination of X-ray diffraction, TGA, Raman spectroscopy and conductivity measurements. The results showed that phosphate could be incorporated into this system up to the 10% doping level, although this required an increased Y/Yb/In content, e.g., BaCe0.6(Y/In/Yb0.3P0.1O2.9. The phosphate doping was, however, shown to lead to a decrease in conductivity; although at low phosphate levels high conductivities were still observed, e.g., for BaCe0.65Y0.3P0.05O2.875, σ = 4.3 × 10−3 S cm−1 at 600 °C in wet N2. In terms of the effect of phosphate incorporation on the CO2 stability, it was shown to lead to a small improvement for the In containing samples, whereas the yttrium doped compositions showed no change in CO2 stability.

  19. Study of the Electrodynamic Response of SmBa2Cu3O7-δ Thin Films in the Microwave Region

    Science.gov (United States)

    Lamura, G.; di Gennaro, E.; Andreone, A.; Boffa, M.; Cucolo, A. M.

    We present some experimental results on the temperature dependence of the surface resistance Rs and magnetic penetration depth λ of thin films of SmBa2Cu3O7-δ. The samples, 0.25 μm thick, were grown by a dc sputtering technique on (100) K LaAlO3 single crystal substrates, with critical temperatures ranging between 87 and 88 K Accurate measurements af the surface impedance Zs were performed down to 4 K by means of a dielectrically loaded cavity operating in the microwave region (20 GHz). Both λ and Rs show a monotonic temperature behavior, with no evidence of low temperature up-turn characteristic of other rare earth based cuprates like GdBa2Cu3O7-δ. At low temperatures, we observed am almost linear behavior of λ with a slope of ~ 0.3 nm/K up to 25 K, as expected in a d-wave pairing scenario. The real part of complex conductivity σ1, shows a bump at around 40 K, in agreement with previous reports.

  20. Improvement in Jc performance below liquid nitrogen temperature for SmBa2Cu3Oy superconducting films with BaHfO3 nano-rods controlled by low-temperature growth

    Directory of Open Access Journals (Sweden)

    S. Miura

    2016-01-01

    Full Text Available For use in high-magnetic-field coil-based applications, the critical current density (Jc of REBa2Cu3Oy (REBCO, where RE = rare earth coated conductors must be isotropically improved, with respect to the direction of the magnetic field; these improvements must be realized at the operating conditions of these applications. In this study, improvement of the Jc for various applied directions of magnetic field was achieved by controlling the morphology of the BaHfO3 (BHO nano-rods in a SmBCO film. We fabricated the 3.0 vol. % BHO-doped SmBCO film at a low growth temperature of 720 °C, by using a seed layer technique (Ts = 720 °C film. The low-temperature growth resulted in a morphological change in the BHO nano-rods. In fact, a high number density of (3.1 ± 0.1 × 103 μm−2 of small (diameter: 4 ± 1 nm, discontinuous nano-rods that grew in various directions, was obtained. In Jc measurements, the Jc of the Ts = 720 °C film in all directions of the applied magnetic field was higher than that of the non-doped SmBCO film. The Jcmin (6.4 MA/cm2 of the former was more than 6 times higher than that (1.0 MA/cm2 of the latter at 40 K, under 3 T. The aforementioned results indicated that the discontinuous BHO nano-rods, which occurred with a high number density, exerted a 3D-like flux pinning at the measurement conditions considered. Moreover, at 4.2 K and under 17 T, a flux pinning force density of 1.6 TN/m3 was realized; this value was comparable to the highest value recorded, to date.

  1. Improvement in Jc performance below liquid nitrogen temperature for SmBa2Cu3Oy superconducting films with BaHfO3 nano-rods controlled by low-temperature growth

    Science.gov (United States)

    Miura, S.; Yoshida, Y.; Ichino, Y.; Xu, Q.; Matsumoto, K.; Ichinose, A.; Awaji, S.

    2016-01-01

    For use in high-magnetic-field coil-based applications, the critical current density (Jc) of REBa2Cu3Oy (REBCO, where RE = rare earth) coated conductors must be isotropically improved, with respect to the direction of the magnetic field; these improvements must be realized at the operating conditions of these applications. In this study, improvement of the Jc for various applied directions of magnetic field was achieved by controlling the morphology of the BaHfO3 (BHO) nano-rods in a SmBCO film. We fabricated the 3.0 vol. % BHO-doped SmBCO film at a low growth temperature of 720 °C, by using a seed layer technique (Ts = 720 °C film). The low-temperature growth resulted in a morphological change in the BHO nano-rods. In fact, a high number density of (3.1 ± 0.1) × 103 μm-2 of small (diameter: 4 ± 1 nm), discontinuous nano-rods that grew in various directions, was obtained. In Jc measurements, the Jc of the Ts = 720 °C film in all directions of the applied magnetic field was higher than that of the non-doped SmBCO film. The Jcmin (6.4 MA/cm2) of the former was more than 6 times higher than that (1.0 MA/cm2) of the latter at 40 K, under 3 T. The aforementioned results indicated that the discontinuous BHO nano-rods, which occurred with a high number density, exerted a 3D-like flux pinning at the measurement conditions considered. Moreover, at 4.2 K and under 17 T, a flux pinning force density of 1.6 TN/m3 was realized; this value was comparable to the highest value recorded, to date.

  2. The crystal structures of R{sub 3}CuGeS{sub 7} (R = Ce-Nd, Sm, Gd-Dy and Er)

    Energy Technology Data Exchange (ETDEWEB)

    Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine); Lychmanyuk, O.S. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine); Wolcyrz, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland)]. E-mail: M.Wolcyrz@int.pan.wroc.pl; Pietraszko, A. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland); Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine)

    2006-11-30

    Crystal structures of R{sub 3}CuGeS{sub 7} (R = Ce, Pr, Nd, Sm, Gd, Tb, Dy and Er) (La{sub 3}CuSiS{sub 7} structure type, space group P6{sub 3}, Pearson symbol hP24) were determined by means of X-ray single crystal diffraction (a = 1.0225(1) nm, c = 0.58350(7) nm, R {sub 1} = 0.0213 for Ce{sub 3}CuGeS{sub 7}; a = 1.0168(1) nm, c 0.58223(7) nm, R {sub 1} = 0.0284 for Pr{sub 3}CuGeS{sub 7}; a = 1.0123(1) nm, c 0.57942(7) nm, R {sub 1} = 0.0240 for Nd{sub 3}CuGeS{sub 7}) and X-ray powder diffraction (a = 1.00144(1) nm, c = 0.57714(1) nm, R {sub Bragg} = 0.0968 for Sm{sub 3}CuGeS{sub 7}; a = 0.99428(1) nm, c = 0.57592(1) nm, R {sub Bragg} = 0.0863 for Gd{sub 3}CuGeS{sub 7}; a = 0.98863(1) nm, c = 0.57535(1) nm, R {sub Bragg} = 0.0838 for Tb{sub 3}CuGeS{sub 7}; a = 0.98371(3) nm, c = 0.57552(3) nm, R {sub Bragg} = 0.0802 for Dy{sub 3}CuGeS{sub 7}; a = 0.97415(1) nm, c = 0.57835(1) nm, R {sub Bragg} = 0.0709 for Er{sub 3}CuGeS{sub 7}). The structures are built up from three-dimensional network of RS{sub 8} distorted square antiprisms sharing edges, consolidated by GeS{sub 4} tetrahedra and CuS{sub 3} triangles sharing edges with the antiprisms.

  3. Fractal and agglomeration behavior in Gd and Sm doped CeO2 nano-crystalline powders

    International Nuclear Information System (INIS)

    Nanocrystalline Gd, Sm doped ceria powders were synthesized by a combustion technique, using glycine as the fuel. These powders, after calcination at 600 oC, were characterized by powder X-ray diffraction and were found to be phase pure. The crystallite sizes, as calculated from X-ray line broadening were in the range of 11-13 nm, which were in close agreement with those obtained from the SAXS studies. The TEM studies also showed the particle sizes to be in the range of 10-15 nm. These powders showed a high surface area as observed from BET technique. The extent and nature of agglomeration was studied by a particle size analyzer. The fractal behaviour of these nano-sized powders prepared by combustion synthesis, has also been investigated by small angle X-ray scattering technique. Results showed that the powders contain aggregates with rough fractal surfaces above a length scale of 20 nm. These parameters of the powders and their agglomerates were found to play a significant role in the sintering behavior

  4. Fractal and agglomeration behavior in Gd and Sm doped CeO{sub 2} nano-crystalline powders

    Energy Technology Data Exchange (ETDEWEB)

    Chavan, S.V. [Applied Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sastry, P.U. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, A.K. [Applied Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: aktyagi@barc.gov.in

    2008-06-12

    Nanocrystalline Gd, Sm doped ceria powders were synthesized by a combustion technique, using glycine as the fuel. These powders, after calcination at 600 {sup o}C, were characterized by powder X-ray diffraction and were found to be phase pure. The crystallite sizes, as calculated from X-ray line broadening were in the range of 11-13 nm, which were in close agreement with those obtained from the SAXS studies. The TEM studies also showed the particle sizes to be in the range of 10-15 nm. These powders showed a high surface area as observed from BET technique. The extent and nature of agglomeration was studied by a particle size analyzer. The fractal behaviour of these nano-sized powders prepared by combustion synthesis, has also been investigated by small angle X-ray scattering technique. Results showed that the powders contain aggregates with rough fractal surfaces above a length scale of 20 nm. These parameters of the powders and their agglomerates were found to play a significant role in the sintering behavior.

  5. Effect of Rare Earth Element in ZrO2-M2O3/MCM-41 (M=La, Ce, Sm, Gd) on Hydrogen Transfer Reaction%稀土元素对ZrO2-M2O3/MCM-41(M=La,Ce,Sm,Gd)氢转移催化活性的影响

    Institute of Scientific and Technical Information of China (English)

    邓冰心; 张波; 姜剑锋

    2015-01-01

    通过浸渍法制备了5%ZrO2/MCM-41、5%ZrO2-5%M2O3/MCM-41(M=La,Ce,Sm,Gd)催化剂,考察其在苯乙酮氢转移还原生成α-苯乙醇反应中的催化活性,同时对样品进行XRD、N2吸附-脱附、吡啶吸附原位红外等表征分析,研究添加稀土金属氧化物对催化剂活性的影响机理.结果表明:ZrO2及稀土金属氧化物均以无定型态或粒度低于XRD检测限的细小晶粒较好地分散在MCM-41介孔分子筛内表面;加入稀土金属氧化物对ZrO2/MCM-41的催化活性有较大影响,催化活性按5%ZrO2-5%La2O3/MCM-41 >5%ZrO2-5%Sm2O3/MCM-41 >5%ZrO2-5%Gd2O3/MCM-41 >5%ZrO2/MCM-41 >5%ZrO2-5%Ce2O3/MCM-41降低.这一方面归因于加入稀土金属氧化物增强了催化剂表面Zr-OH、L酸中心及B酸中心的酸性,另一方面归因于La2O3的加入使催化剂表面酸中心数目明显提高,Sm2O3、Gd2O3的加入使催化剂表面酸中心数目有所降低,而加入Ce2O3使催化剂表面酸中心数目显著减少.

  6. Yttrium doped BaCeO3 thin films by spray pyrolysis technique for application in solid oxide fuel cell

    International Nuclear Information System (INIS)

    Highlights: • BCY20 thin electrolyte was deposited by economical spray pyrolysis technique. • Solution concentration and annealing temperature affects structure and morphology. • Excellent agreement with XRD data of lattice parameter. • The dc conductivity in argon at 600 °C was 4.25 × 10−3 S cm−1. -- Abstract: Yttrium doped barium cerate (BCY) a solid state ion conductor which exhibits proton conductivity under proper atmospheric conditions, is used as an electrolyte in a solid oxide fuel cell (SOFCs). In present work, nanocrystalline BaCe0.8Y0.2O2.9 (BCY20) thin films were successfully deposited onto alumina substrates by simple and economical spray pyrolysis technique (SPT) at 250 °C. The effect of solution concentration and annealing on physico-chemical properties of BCY20 thin film has been studied. The X-ray diffraction (XRD) studies of spray pyrolysed BCY20 films revealed polycrystalline (crystallite size 35 nm) orthorhombic structure with lattice parameters a = 8.77 Å, b = 6.234 Å and c = 6.223 Å. The scanning electron micrographs showed dense morphology which is very useful for electrolyte. The stoichiometry was confirmed by elemental analysis and the estimated atomic ratio was in good agreement with that of the precursor solution ratio. The most intense band at 353.26 cm−1 observed in room temperature Raman spectrum of BCY20 film was due to vibrational mode of barium cerate. The FTIR spectra with heat treatment shows no carbon based vibration bonds, revealing absence of carbon based surface impurities in the sample. The dc conductivities measured in air and argon atmospheres at 600 °C were 1.7 × 10−3 and 4.25 × 10−3 S cm−1, respectively

  7. The pressure effect on crystal structure of complex ferroelectrics Ba{sub 4}Sm{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} and Ba{sub 4}Gd{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30}

    Energy Technology Data Exchange (ETDEWEB)

    Jabarov, Sakin H. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Azerbaijan National Academy of Sciences, Baku (Azerbaijan). Inst. of Physics; Kichanov, Sergey E. [Joint Institute for Nuclear Research, Dubna (Russian Federation). Frank Lab of Neutron Physics; Kozlenko, Denis P.; Lukin, Evgeniy V.; Savenko, Boris N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Mehdiyeva, Rafiga Z.; Mammadov, Ali I. [Azerbaijan National Academy of Sciences, Baku (Azerbaijan). Inst. of Physics; Lathe, Christian [Helmholtz Centre Potsdam (Germany). German Research Centre for Geosciences

    2014-07-01

    The crystal structure of complex oxide ferroelectrics Ba{sub 4}Sm{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} and Ba{sub 4}Gd{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} have been studied by means of energy-dispersive X-ray diffraction method at high pressure up to 4 GPa at room temperature. At ambient pressure, the crystal structure of both compounds is described by the tetragonal symmetry with space group P4/mbm. At pressure P∝1.8 GPa in Ba{sub 4}Sm{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} and at P∝2.2 GPa in Ba{sub 4}Gd{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} the structure phase transition have been observed. The orthorhombic structure model with Pba2 space group for high-pressure phase of those compounds have been proposed. The baric dependences of lattice parameters and unit cell volumes of Ba{sub 4}Sm{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} and Ba{sub 4}Gd{sub 2}Fe{sub 2}Nb{sub 8}O{sub 30} compounds have been obtained.

  8. Microstructure and microwave dielectric properties of Ba6-3xSm8+2xTi18Os4ceramics with various BaxSr1-xTiO3 additions

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lingling; ZHOU Hongqing; SHAO Hui; ZHU Haikui

    2012-01-01

    The Ba6-3xSm8+2xTi18O54 (x=2/3) microwave dielectric ceramics were prepared by traditional solid sate reaction technique.The experiment was based on the Ba6-3xSm8+2xTi18O54 (BST) microwave dielectric ceramics doped with a certain amount of Bi2O3,then the effects of BaxSr1-xTiO3 additives on the structure and microwave dielectric properties of Ba6-3xSm8+2xTi18O54 ceramics were investigated using X-ray diffraction and scanning electron microscopy.In this study,the small amount substitution of Sr for Ba was effective for the microwave dielectric properties of BST,especially the τf could be tuned to near zero.The result showed that the BST possessed excellent dielectric properties when the addition of Bi2O3 and BaxSr1-xTiO3 was 1 wt.% respectively:εr=79.6,Qf=10789 GHz,τf=-1.5 ppm/℃.

  9. A robust NiO-Sm0.2Ce0.8O1.9 anode for direct-methane solid oxide fuel cell

    KAUST Repository

    Tian, Dong

    2015-07-02

    In order to directly use methane without a reforming process, NiO-Sm0.2Ce0.8O1.9 (NiO-SDC) nanocomposite anode are successfully synthesized via a one-pot, surfactant-assisted co-assembly approach for direct-methane solid oxide fuel cells. Both NiO with cubic phase and SDC with fluorite phase are obtained at 550 °C. Both NiO nanoparticles and SDC nanoparticles are highly monodispersed in size with nearly spherical shapes. Based on the as-synthesized NiO-SDC, two kinds of single cells with different micro/macro-porous structure are successfully fabricated. As a result, the cell performance was improved by 40%-45% with the new double-pore NiO-SDC anode relative to the cell performance with the conventional NiO-SDC anode due to a wider triple-phase-boundary (TPB) area. In addition, no significant degradation of the cell performance was observed after 60 hours, which means an increasing of long term stability. Therefore, the as-synthesized NiO-SDC nanocomposite is a promising anode for direct-methane solid oxide fuel cells.

  10. Determination of the upper critical field of the electron-doped superconductor Sm1.85Ce0.15CuO4-y from resistive fluctuations

    International Nuclear Information System (INIS)

    The upper critical field Hc2(T) for the magnetic field applied parallel to the c axis of a Sm1.85Ce0.15CuO4-y single crystal has been determined from an analysis of magnetoresistance data in terms of the Ginzburg-Landau fluctuation theory for layered superconductors. The fluctuations are predominantly two dimensions (2D) away from Tc(H) with a crossover to 3D as Tc(H) is approached. The Hc2(T) curve shows negative curvature and is in excellent agreement with the Werthamer, Helfand, Hohenberg, and Maki theory for conventional superconductors without paramagnetic limiting effects. The values of the initial slope (dHc2/dT)Tc=-7.38 kOe/K, coherence length ξ(0)=48.4 A, and orbital critical field Hc2(0)=97.6 kOe, derived from this analysis, are in good agreement with the values we previously obtained from fits of the Hao-Clem variational model to reversible magnetization data below Tc

  11. Effects of laminating and co-firing conditions on the performance of anode-supported Ce0.8Sm0.201.9 film electrolyte

    Directory of Open Access Journals (Sweden)

    Li X.

    2011-01-01

    Full Text Available In order to evaluate the laminating and co-firing technique on the performance of anode-supported Ce0.8Sm0.2O1.9 (SDC film electrolyte and its single cell, NiO-YSZ and NiOSDC anode-supported SDC film electrolytes were fabricated by laminating 24 sheets of anode plus one sheet of electrolyte and co-firing. La0.4Sr0.6Co0.2Fe0.8O3-δ (LSCF-SDC cathode was coated on the SDC electrolytes to form a single cell. The lamination was tried at different laminating temperatures and pressures and the co-firing was carried out at different temperatures. The results showed that the laminating temperature should above the glass transition temperature (Tg of the binder. The laminating pressure of 70 MPa resulted in warp of the samples. The best co-firing temperature of the anode-supported SDC film electrolyte was 1400°C. The SDC film electrolyte formed well adherence to the anode. The NiO-YSZ anode had larger flexural strength than the NiO-SDC anode. The NiO-YSZ anode-supported SDC film electrolyte single cell had an open circuit voltage of 0.803 V and a maximum power density of 93.03 mW/cm2 with hydrogen as fuel at 800°C.

  12. Thermochemical Properties of the Complexes RE(HSal)3·2H2O (RE=La, Ce, Pr, Nd, Sm)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Five solid rare earth salicylate complexes were synthesized by low hydrated lathanide chloride and salicylic acid. The complexes in this experiment were identified as the general formula RE(Hsal)3·2H2O(RE=La, Ce, Pr, Nd, Sm) by elemental analysis and EDTA volumetric analysis. IR spectra of the complexes show that carboxyl of salicylic acid coordinates to RE3+ ions. Electrochemical behaviors of the complexes on the glass-carbon electrode were researched with cyclic voltammetry (CV). It is indicated that the electrochemical process of the complexes is a one-electron redox process and the electrochemical reversibility of complexes is less than that of the lanthanide chlorides. The constant-volume combustion energies of complexes, ΔcU, were determined with a precise rotating-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, ΔcHθm, and standard molar enthalpies of formation, ΔfHθm, were calculated.

  13. Photoluminescence spectra of thenardite Na{sub 2}SO{sub 4} activated with rare-earth ions, Ce{sup 3+}, Sm{sup 3+}, Tb{sup 3+}, Dy{sup 3+} and Tm{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Sidike, Aierken [School of Physics and Electronic Engineering, Xinjiang Normal University, Urumqi, 830054 Xinjiang (China); Saliqur, Rahman Abu Zayed Mohammad [Graduate School of Natural Science and Technology, Okayama University, Tsushima-naka, Kita-ku, 700-8530 Okayama (Japan); He Juiyang [Graduate School of Physics and Electronic Engineering, Xinjiang Normal University, Urumqi, 830054 Xinjiang (China); Gong Lanxin [School of Life Science and Chemistry, Xinjiang Normal University, Urumqi, 830054 Xinjiang (China); Atobe, K. [Department of Physics, Faculty of Education, Okayama University, Tsushima-naka, Kita-ku, 700-8530 Okayama (Japan); Yamashita, N., E-mail: yosiko3@io.ocn.ne.jp [Department of Physics, Faculty of Education, Okayama University, Tsushima-naka, Kita-ku, 700-8530 Okayama (Japan)

    2011-09-15

    Five Na{sub 2}SO{sub 4}:RE{sup 3+} phosphors activated with rare-earth (RE) ions (RE{sup 3+}=Ce{sup 3+}, Sm{sup 3+}, Tb{sup 3+}, Dy{sup 3+} and Tm{sup 3+}) were synthesized by heating natural thenardite Na{sub 2}SO{sub 4} from Ai-Ding Salt Lake, Xinjiang, China with small amounts of rare-earth fluorides, CeF{sub 3}, SmF{sub 3}, TbF{sub 3}, DyF{sub 3} and TmF{sub 3}, at 920 {sup o}C in air. The photoluminescence (PL) and optical excitation spectra of the obtained phosphors were measured at 300 and 10 K. In the PL spectrum of Na{sub 2}SO{sub 4}:Ce{sup 3+} at 300 K, two overlapping bands with peaks at 335 and 356 nm due to Ce{sup 3+} were first observed. Narrow bands observed in PL and excitation spectra of Na{sub 2}SO{sub 4}:RE{sup 3+} (RE{sup 3+}=Sm{sup 3+}, Tb{sup 3+}, Dy{sup 3+} and Tm{sup 3+}) phosphors were well identified with the electronic transitions within the 4f{sup n} (n=5, 8, 9 and 12) configurations of RE{sup 3+}. The existence of excitation bands with high luminescence efficiency at wavelengths shorter than 230 nm is characteristic of Na{sub 2}SO{sub 4}:RE{sup 3+} (RE{sup 3+}=Sm{sup 3+}, Tb{sup 3+}, Dy{sup 3+} and Tm{sup 3+}) phosphors. The obtained results suggest that these phosphors are unfavorable as the phosphor for usual fluorescence tubes, i.e., mercury discharge tubes, but may be favorable as the phosphor for UV-LED fluorescent tubes and as cathodoluminescence, X-ray luminescence and thermoluminescence phosphors. - Highlights: > Five Na{sub 2}SO{sub 4}:RE{sup 3+} (RE{sup 3+}=Ce{sup 3+}, Sm{sup 3+}, Tb{sup 3+}, Dy{sup 3+} and Tm{sup 3+}) phosphors were synthesized by heating natural thenardite. > The emission and excitation spectra of the obtained phosphors were measured at 300 and 10 K. > In Na{sub 2}SO{sub 4}:Ce{sup 3+} at 300 K, two overlapping emission bands with peaks at 335 and 356 nm were first observed.

  14. First-principles study of structural, electronic, magnetic and thermodynamic properties of the double perovskite Ba2CeCoO6

    Science.gov (United States)

    Xie, Huan-Huan; Gao, Qiang; Li, Lei; Lei, Gang; Hu, Xian-Ru; Deng, Jian-Bo

    2016-07-01

    The structural, electronic and magnetic properties of cubic double perovskite Ba2CeCoO6 were calculated using first-principles full-potential local-orbital minimum-basis method. This compound has a cubic crystal structure with space group Fm 3 bar m. By analysing the band structure we found, at the equilibrium lattice constant, this compound is a half-metal. Moreover, the half-metallicity can be kept under a large range of pressure. Meanwhile, the thermodynamic characters are investigated using the quasi-harmonic Debye model.

  15. Synthesis, Sintering, and Electrical Properties of BaCe0.9−xZrxY0.1O3−δ

    Directory of Open Access Journals (Sweden)

    S. Ricote

    2008-01-01

    Full Text Available BaCe0.9−xZrxY0.1O3−δ powders were synthesized by a solid-state reaction. Different contents of cerium and zirconium were studied. Pellets were sintered using either conventional sintering in air at 1700∘C or the Spark Plasma Sintering (SPS technique. The density of the samples sintered by SPS is much higher than by conventional sintering. Higher values of ionic conductivity were obtained for the SPS sample.

  16. Structural, magnetic and magnetotransport properties of La0.7-CeBa0.3MnO3 ( = 0.0-0.4)

    Indian Academy of Sciences (India)

    R Vengadesh Kumara Mangalam; A Sundaresan

    2006-01-01

    Structural, magnetic and magnetotransport properties of La0.7-CeBa0.3MnO3 ( = 0-0.4) have been investigated although some unreacted secondary phases of CeO2 were present. The rhombohedral structure (-3) for = 0 transforms to orthorhombic with the space group Imma for = 0.3. All samples showed ferromagnetic transition above 300 K and a negative magnetoresistance. For > 0.1, magnetization data measured at 1 T showed a decrease at low temperatures ( < 50 K) due to antiferromagnetic coupling between Ce-local moments and Mn-moments. For = 0.4, the resistivity showed a maximum around 200 K which corresponds to ordering temperature of cerium. Since these results are similar to that observed in the Sr-containing La0.5-CeSr0.5MnO3 ( = 0-0.4) system, we suggest that the cerium ions are in the trivalent state and the anomalous behaviour has been attributed to a Kondo-like effect.

  17. Crystal structure, Raman spectroscopy and microwave dielectric properties of layered-perovskite BaA{sub 2}Ti{sub 3}O{sub 10} (A = La, Nd and Sm) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Santosh Kumar; Murthy, V.R.K., E-mail: vrkm@iitm.ac.in

    2015-06-15

    Dependence of microwave dielectric properties on the structural characteristics of BaA{sub 2}Ti{sub 3}O{sub 10} (A = La, Nd and Sm) was investigated. All the compounds were prepared by solid-state reaction method and the structural parameters were obtained from Rietveld refinement of powder diffraction data of the compounds. The dielectric constant (ε{sub r}) increased due to decrease in molar volume of the compound, which was observed as a result of smaller ionic radii. Quality factor (Q × ƒ) of BaSm{sub 2}Ti{sub 3}O{sub 10} (BST) and BaLa{sub 2}Ti{sub 3}O{sub 10} (BLT) were found to be lowest (10,490 GHz) and highest (20,860 GHz) respectively, which was explained in terms of average bond strength between B-site cations and oxygen anions. Raman spectroscopy was also used to analyze the B–O bond strength with the help of A{sub g} mode. The temperature coefficient of resonant frequency (τ{sub ƒ}) was correlated with respective octahedral-distortion in the structure. - Highlights: • Increase of B-site bond strength enhanced the quality factor. • FWHM of A{sub g} mode also confirmed the increase of quality factor from Sm to La. • Effect of B-site octahedral distortion on τ{sub f}.

  18. Crystal Chemistry of the New Families of Interstitial Compounds R6Mg23C (R = La, Ce, Pr, Nd, Sm, or Gd) and Ce6Mg23Z (Z = C, Si, Ge, Sn, Pb, P, As, or Sb).

    Science.gov (United States)

    Wrubl, Federico; Manfrinetti, Pietro; Pani, Marcella; Solokha, Pavlo; Saccone, Adriana

    2016-01-01

    The crystal chemical features of the new series of compounds R6Mg23C with R = La-Sm or Gd and Ce6Mg23Z with Z = C, Si, Ge, Sn, Pb, P, As, or Sb have been studied by means of single-crystal and powder X-ray diffraction techniques. All phases crystallize with the cubic Zr6Zn23Si prototype (cF120, space group Fm3̅m, Z = 4), a filled variant of the Th6Mn23 structure. While no Th6Mn23-type binary rare earth-magnesium compound is known to exist, the addition of a third element Z (only 3 atom %), located into the octahedral cavity of the Th6Mn23 cell (Wyckoff site 4a), stabilizes this structural arrangement and makes possible the formation of the ternary R6Mg23Z compounds. The results of both structural and topological analyses as well as of LMTO electronic structure calculations show that the interstitial element plays a crucial role in the stability of these phases, forming a strongly bonded [R6Z] octahedral moiety spaced by zeolite cage-like [Mg45] clusters. Considering these two building units, the crystal structure of these apparently complex intermetallics can be simplified to the NaCl-type topology. Moreover, a structural relationship between RMg3 and R6Mg23C compounds has been unveiled; the latter can be described as substitutional derivatives of the former. The geometrical distortions and the consequent symmetry reduction that accompany this transformation are explicitly described by means of the Bärnighausen formalism within group theory.

  19. Analysis of Fe, Ca, Ti, Ba, Ce, Zr and La element in the Sea sediment at Muria peninsula by X RF method

    International Nuclear Information System (INIS)

    he analysis of metals (Fe, Ca, Ti, Ba, Ce, Zr and La) in the sea sediment environmental samples at Muria peninsula has been carried out with X-Ray Fluorescence (XRF) method. The aim of this analysis is to know the distribution metals which accommodate the recent environmental data in supporting the license of site and Environmental Impact Assessment (EIA) for the Nuclear Power Plants (NPP). Samples taken preparation and analysis based on the procedures of environmental analysis. The result analysis that contents of mayor elements in 7 sea sediment location of sampling were Ca, Ti and Fe with concentration are (6.74 – 11.69 ) %; (0.74 – 6.89 ) % and (0.45 -1.94 ) % successively; while minor elements were Ba, Ce, Zr and La with concentration are 451.4 – 1331.6 ) mg/kg; (201.8 – 427.3) mg/kg; (192.3 – 338.5) mg/kg dan (171.7 – 298.4) mg/kg. The statistic test result shows that sampling location there is a significant difference all of element with the level significant of 95 %. (author)

  20. Catalytic features of Ni/Ba-Ce{sub 0.9}-Y{sub 0.1} catalyst to produce hydrogen for PCFCs by methane reforming

    Energy Technology Data Exchange (ETDEWEB)

    Frontera, P.; Modafferi, V.; Antonucci, P.L. [Dept. of Mechanics and Materials, Mediterranea University, Feo di Vito, 89060 Reggio Calabria (Italy); Frusteri, F.; Bonura, G.; Bottari, M.; Siracusano, S. [CNR-ITAE ' ' Nicola Giordano' ' , via S. Lucia sopra Contesse, 5 - 98126 Messina (Italy)

    2010-10-15

    Methane reforming in steam (SR), auto-thermal (ATR) and partial oxidation (POX) conditions over Ni/Ba-Ce{sub 0.9}-Y{sub 0.1} catalyst was investigated in the temperature range 500-700 C. Catalyst presents a satisfying activity in POX condition only. BCY carrier was not stable in the presence of CO{sub 2} and, irrespective of reaction conditions, it reacts with CO{sub 2} giving rise to the formation of BaCO{sub 3} and CeO{sub 2}. The very low activity observed in SR conditions was due to the negative role exerted by water strongly absorbed on catalyst surface, limiting so the accessibility and reduction state of Ni active sites. In POX condition catalyst is active and satisfying H{sub 2} yield can be reached by operating at T = 700 C. A significant reduction of coke formation was observed by operating in POX at 700 C. On the contrary, in ATR condition at the same reaction temperature huge amount of filamentous coke was observed. (author)

  1. Synthesis, structure and ionic conductivity in scheelite type Li0.5Ce0.5−LnMoO4 ( = 0 and 0.25, Ln = Pr, Sm)

    Indian Academy of Sciences (India)

    Dipankar Saha; Giridhar Madras; Aninda J Bhattacharyya; Tayur N Guru Row

    2011-01-01

    Scheelite type solid electrolytes, Li0.5Ce0.5−LnMoO4 ( = 0 and 0.25, Ln = Pr, Sm) have been synthesized using a solid state method. Their structure and ionic conductivity () were obtained by single crystal X-ray diffraction and ac-impedance spectroscopy, respectively. X-ray diffraction studies reveal a space group of 41/ for Li0.5Ce0.5−LnMoO4 ( = 0 and 0.25, Ln = Pr, Sm) scheelite compounds. The unsubstituted Li0.5Ce0.5MoO4 showed lithium ion conductivity ∼ 10−5-10−3 −1cm-1 in the temperature range of 300-700°C ( = 2.5 × 10−3 −1cm-1 at 700°C). The substituted compounds show lower conductivity compared to the unsubstituted compound, with the magnitude of ionic conductivity being two (in the high temperature regime) to one order (in the low temperature regime) lower than the unsubstituted compound. Since these scheelite type structures show significant conductivity, the series of compounds could serve in high temperature lithium battery operations.

  2. Preparation of Eu2+ and Ce3+ co-activated phosphors with optimal composition in (Ba,Sr)2ZnS3 solid solution series by polymerizable complex method

    International Nuclear Information System (INIS)

    The series of Ba2-xSrxZnS3:Eu2+,Ce3+ (x = 0.3, 0.4, 0.5) red emission phosphors was synthesized by a solution based technique employing polymerizable complex method. The prepared materials conformed to Ba2MnS3 type crystal structure. Red fluorescence could be efficiently exited by the blue light of 445nm; thus these phosphors are prospective in white LED lighting application. The emission intensity vs. Sr concentration showed a distinct maximum at x = 0.4, while co-doping with Eu2+ and Ce3+ allowed for enhancement of emission intensity by 5-15% compared to the Ce free samples. The maximum emission intensity at 670nm exhibited by the material with optimal Sr concentration approached 80% compared to one of the best commercially available YAG:Ce3+.

  3. Magnetic manipulation by resistance switching in CeO2/PrBa2Cu3O7−δ/Pt heterostructure: The role of oxygen vacancies

    International Nuclear Information System (INIS)

    Pronounced bipolar resistance switching with a good retention property has been observed in CeO2/PrBa2Cu3O7−δ/Pt heterostructure. The low resistance state and high resistance state exhibited distinguished ferromagnetic signals, as compared to the nearly non-magnetic initial state. It is found that the migration of the oxygen vacancies under electric field is mainly responsible for the electric and the magnetic changes. The modified interfacial electronic structure by the oxygen vacancy migration and the trapping/detrapping of the carriers leads to the resistance switching. The exchange interaction of the hydrogen-like orbitals formed around the singly occupied oxygen vacancies in CeO2 is accounting for the emerged and modulated ferromagnetic signals. Temperature dependence of resistance in the low resistance state follows a variable range hopping law, further confirming that the amount of oxygen vacancies in the CeO2 layer directly affects the hydrogen-like orbital radius, which determines the strength of the ferromagnetic coupling

  4. Influence of anode pore forming additives on the densification of supported BaCe0.7Ta0.1Y0.2O3−δ electrolyte membranes based on a solid state reaction

    NARCIS (Netherlands)

    Bi, Lei; Fang, Shumin; Tao, Zetian; Zhang, Shangquan; Peng, Ranran; Liu, Wei

    2009-01-01

    We describe a solid state reaction for the preparation of both NiO–BaCe0.7Ta0.1Y0.2O3−δ anode substrates and BaCe0.7Ta0.1Y0.2O3−δ (BCTY10) electrolyte membranes on porous NiO–BCTY10 anode substrates. The amounts of the pore forming additive in the substrates showed a significant influence on the den

  5. Complexes of o-Vanillin oxime with La(III), Ce(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III), Ho(III) and Yb(III)

    International Nuclear Information System (INIS)

    Ten complexes of lanthanides with o-vanillin oxime have been swynthesised and characterised. The composition of the complexes as determined by elemental and thermal analyses, infrared electronic spectral and magnetic moment studies is [Ln(C8H8NO3)3.XH2O], where X=2 when Ln=La, Ce, Pr, Nd, Sm and X=3 when Ln=Gd, Dy, Tb, Ho, Yb; C8H8NO3- represents the anion of the ligand. (author). 16 refs., 2 figs., 2 tables

  6. Thermoelastic and structural properties of ionically conducting cerate perovskites: (I) BaCeO3 at low temperature in the Pbnm phase

    DEFF Research Database (Denmark)

    Knight, Kevin S.; Bonanos, Nikolaos

    2013-01-01

    parameter. Structural parameters are presented as the amplitudes of the seven symmetry-adapted basis-vectors of the aristotype phase, and a structural basis for the temperature-dependence of the bond lengths is outlined. The critical exponent associated with the temperature variation of the primary order......The thermoelastic and structural properties of BaCeO3 perovskite in the Pbnm phase field have been studied using high resolution neutron diffractometry at 37 temperatures between 2 K and 350 K. From a simultaneous fit of the isochoric heat capacity and unit cell volume, the vibrational density...... of states in the Pbnm phase is shown to be approximated by a two-term modified Debye model with characteristic temperatures 176(1) K and 543(2) K. Vibrational Debye temperatures, determined from the temperature-variation of the atomic displacement parameters, suggest the cations to be more associated...

  7. Hydrogen Permeation Properties of Perovskite-type BaCe0.9Mn0.1O3-δDense Ceramic Membrane

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The electrical conduction properties of dense BaCe0.9Mn0.1O3-δ (BCM10) membrane were investigated in the temperature range of 600-900℃. High ionic and electronic conductivities at elevated temperatures make BCM10 a potential ceramic material for hydrogen separation. Hydrogen permeation through BCM10 membranes was studied using a hightemperature permeation cell. Little hydrogen could be detected at the sweep side. However,appreciable hydrogen can permeate through BCM10 membrane coated with porous platinum black,which shows that the process of hydrogen permeation through BCM10 membranes was controlled by the catalytic decomposition and recomposition of hydrogen on the surfaces of BCM10 membranes.

  8. Chemical stability and electrical property of Ba1.03Ce0.6Zr0.2Yb0.2O3-α ceramic

    Institute of Scientific and Technical Information of China (English)

    WANG Maoyuan; QIU Ligan; CAO Xu

    2011-01-01

    Ba1.03Ce0.6Zr0.2Yb0.2O3-α ceramic was prepared by solid state reaction.Phase composition,surface and cross-section morphologies of the material were characterized by using X-ray diffractometer (XRD) and scanning electron microscopy (SEM),respectively.Its chemical stability against carbon dioxide and water steam at high temperature was tested.Ionic conduction of the material was investigated by ac impedance spectroscopy and gas concentration cell methods under different gas atmospheres in the temperature range of 500-900 ℃.Using the ceramic as solid electrolyte and porous platinum as electrodes,the hydrogen-air fuel cell was constructed,and the cell performance at the temperature from 500 to 900 ℃ was examined.The results indicated that Ba1.03Ce06Zr0.2Yb0.2O3-α was a single-phase perovskite-type orthorhombic system,with high density and good chemical stability under carbon dioxide and water steam atmospheres at high temperature.In wet hydrogen,the material was a pure protonic conductor with the protonic transport number of I from 500 to 700 ℃,a mixed conductor of proton and electron with the protonic transport numbers of 0.945-0.916 from 800 to 900 ℃.In wet air,the material was a mixed conductor of proton,oxide ion and electronic hole.The protonic transport numbers were 0.013-0.003,and the oxide ionic transport numbers were 0.346-0.265.Under hydrogen-air fuel cell conditions,the material was a mixed conductor of proton,oxide ion and electron,the ionic transport numbers were 0.945-0.848.The fuel cell could work stably,and at 900 ℃,the maximum power output density was 36.5 mW/cm2.

  9. Crystal structure of the R{sub 3}Ag{sub 1-{delta}}SiS{sub 7} (R = La, Ce, Pr, Nd, Sm, {delta} = 0.10-0.23) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Daszkiewicz, M. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna Street 2, P.O. Box 1410, Wroclaw 50-950 (Poland)], E-mail: m.daszkiewicz@int.pan.wroc.pl; Gulay, L.D. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna Street 2, P.O. Box 1410, Wroclaw 50-950 (Poland); Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, Lutsk 43009 (Ukraine); Lychmanyuk, O.S. [Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, Lutsk 43009 (Ukraine); Pietraszko, A. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna Street 2, P.O. Box 1410, Wroclaw 50-950 (Poland)

    2008-07-28

    The crystal structure of the R{sub 3}Ag{sub 1-{delta}}SiS{sub 7} (R = La, Ce, Pr, Nd, Sm, {delta} = 0.10-0.23, space group P6{sub 3}, Pearson symbol hP23.80 - 23.54) compounds were determined by means of X-ray single crystal diffraction (a = 1.04168(8) nm, c = 0.57825(4) nm, R1 = 0.0116 for La{sub 3}Ag{sub 0.90}SiS{sub 7}; a = 1.0312(1) nm, c = 0.57395(7) nm, R1 = 0.0152 for Ce{sub 3}Ag{sub 0.82}SiS{sub 7}; a = 1.0248(1) nm, c = 0.57223(5) nm, R1 = 0.0105 for Pr{sub 3}Ag{sub 0.85}SiS{sub 7}; a = 1.0192(1) nm, c = 0.57020(6) nm, R1 = 0.0292 for Nd{sub 3}Ag{sub 0.81}SiS{sub 7}, a = 1.0100(1) nm, c = 0.56643(6) nm, R1 = 0.0208 for Sm{sub 3}Ag{sub 0.77}SiS{sub 7}. Gradual decrease of the silver amount in the series of chalcogenides was found.

  10. Crystal structure and magnetic properties of R{sub 3}Fe{sub 0.5}GeS{sub 7} (R = Y, La, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er and Tm)

    Energy Technology Data Exchange (ETDEWEB)

    Daszkiewicz, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław (Poland); Pashynska, Yu.O. [Department of Material Science, Lutsk National Technical University, L’vivska str. 75, 43018 Lutsk (Ukraine); Marchuk, O.V. [Department of Inorganic and Physical Chemistry, Eastern European National University, Voli Ave 13, 43009 Lutsk (Ukraine); Gulay, L.D. [Department of Ecology and Protection of Environment, Eastern European National University, Voli Ave 13, 43009 Lutsk (Ukraine); Kaczorowski, D., E-mail: D.Kaczorowski@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław (Poland)

    2014-12-15

    Highlights: • Identification of eleven novel R{sub 3}Fe{sub 0.5}GeS{sub 7} compounds. • Refinement of their crystal structures from single crystal XRD data. • Determination of magnetic behaviour in eight R{sub 3}Fe{sub 0.5}GeS{sub 7} phases. - Abstract: The crystal structure of quaternary compounds R{sub 3}Fe{sub 0.5}GeS{sub 7} (R = Y, La, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er and Tm) was determined by means of single-crystal and powder X-ray diffraction methods. It is of the hexagonal La{sub 3}Mn{sub 0.5}SiS{sub 7} type (space group P6{sub 3}, Pearson symbol hP23) The R atoms occupy trigonal prisms capped with two additional atoms, the Fe atoms are located inside octahedra, and the Ge atoms have tetrahedral environment. Magnetic properties of the compounds R{sub 3}Fe{sub 0.5}GeS{sub 7} (R = Ce, Pr, Sm, Gd, Tb, Dy, Er and Tm) were studied down to 1.72 K. Their magnetic behaviour results from combined contributions due to R{sup 3+} and Fe{sup 2+} sublattices. In each material magnetic exchange interactions are dominated by antiferromagnetic correlations. In most of them, the exchange interactions give rise to long-range magnetic orderings at low temperatures.

  11. Magnetic hyperfine interactions on Cd sites of the rare-earth cadmium compounds R Cd (R =Ce , Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er)

    Science.gov (United States)

    Cavalcante, F. H. M.; Leite Neto, O. F. L. S.; Saitovitch, H.; Cavalcante, J. T. P. D.; Carbonari, A. W.; Saxena, R. N.; Bosch-Santos, B.; Pereira, L. F. D.; Mestnik-Filho, J.; Forker, M.

    2016-08-01

    This paper reports the investigation of the magnetic hyperfine field Bh f in a series of rare-earth (R ) cadmium intermetallic compounds R Cd and GdCd2 measured by perturbed angular correlation (PAC) spectroscopy using 111In/111Cd as probe nuclei at Cd sites as well as first-principles calculations of Bh f at Cd sites in the studied compounds. Vapor-solid state reaction of R metals with Cd vapor and the 111In radioisotope was found to be an appropriate route of doping rare-earth cadmium compounds with the PAC probe 111In/111Cd. The observation that the hyperfine parameters depend on details of the sample preparation provides information on the phase preference of diffusing 111In in the rare-earth cadmium phase system. The 111Cd hyperfine field has been determined in the compounds R Cd for the R constituents Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er, in several cases as a function of temperature. For most R constituents, the temperature dependence Bh f(T ) of 111Cd:R Cd is consistent with ferromagnetic order of the compound. DyCd, however, presents a remarkable anomaly: a finite magnetic hyperfine field is observed only in the temperature interval 35 K ≤ T ≤ 80 K which indicates a transition from ferromagnetic order to a spin arrangement where all 4 f -induced contributions to the magnetic hyperfine field at the Cd site cancel. First-principles calculation results for DyCd show that the (π , π , 0) antiferromagnetic configuration is energetically more favorable than the ferromagnetic. The approach used in the calculations to simulate the R Cd system successfully reproduces the experimental values of Bh f at Cd sites and shows that the main contribution to Bh f comes from the valence electron polarization. The de Gennes plot of the hyperfine field Bh f of 111Cd:R Cd vs the 4 f -spin projection (g -1 )J reflects a decrease of the strength of indirect 4 f -4 f exchange across the R series. Possible mechanisms are discussed and the experimental results indicate that

  12. New tetragonal derivatives of cubic NaZn{sub 13}-type structure: RNi{sub 6}Si{sub 6} compounds, crystal structure and magnetic ordering (R=Y, La, Ce, Sm, Gd–Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Pani, M.; Manfrinetti, P.; Provino, A. [INFM and Dipartimento di Chimica e Chimica Industriale, Universita‘ di Genova, Via Dodecaneso 31, 16146 Genova (Italy); Yuan, Fang; Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4M1 (Canada); Morozkin, A.V., E-mail: morozkin@general.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Knotko, A.V.; Garshev, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Isnard, O. [Université Grenoble Alpes, Inst NEEL, BP166, F-38042 Grenoble (France); CNRS, Institut NEEL, 25 rue des martyrs, F-38042 Grenoble (France)

    2014-02-15

    Novel RNi{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure for R=La–Ce (tP52, space group P4/nbm N 125-1) and new YNi{sub 6}Si{sub 6}-type structure for R=Y, Sm, Gd–Yb (tP52, space group P4{sup ¯}b2N 117) that are tetragonal derivative of NaZn{sub 13}-type structure, like LaCo{sub 9}Si{sub 4}-type. The CeNi{sub 6}Si{sub 6}, GdNi{sub 6}Si{sub 6}, TbNi{sub 6}Si{sub 6}, DyNi{sub 6}Si{sub 6} and HoNi{sub 6}Si{sub 6} compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 5 K. However, the inverse paramagnetic susceptibility of LaNi{sub 6}Si{sub 6} does not follow Curie–Weiss law. The DyNi{sub 6}Si{sub 6} shows ferromagnetic-like saturation behaviour at 5 K in applied fields of 50 kOe, giving rise to a magnetic moment value of 6.5 μ{sub B}/f.u. in 50 kOe. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi{sub 6}Si{sub 6} with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. - Graphical abstract: Novel (La, Ce)Ni{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure and (Y, Sm, Gd–Yb) adopt the new YNi{sub 6}Si{sub 6}-type structure that are tetragonal derivative of NaZn{sub 13}-type structure, like LaCo{sub 9}Si{sub 4}-type. The CeNi{sub 6}Si{sub 6}, GdNi{sub 6}Si{sub 6}, TbNi{sub 6}Si{sub 6}, DyNi{sub 6}Si{sub 6} and HoNi{sub 6}Si{sub 6} compounds are Curie–Weiss paramagnets down to ∼30 K, and do not order magnetically down to 4.2 K. The powder neutron diffraction study in zero applied filed indicates square modulated the c-collinear antiferromagnetic ordering of TbNi{sub 6}Si{sub 6} with K=[±1/4, ±1/4, 0] wave vector below ∼10 K. Display Omitted - Highlights: • The new (La, Ce)Ni{sub 6}Si{sub 6} compounds adopt the new CeNi{sub 6}Si{sub 6}-type structure. • The new (Y, Sm, Gd–Yb)Ni{sub 6}Si{sub 6} compounds adopt the new YNi{sub 6}Si{sub 6}-type structure. • TbNi{sub 6}Si

  13. Preparation and Gas Sensitivity Study of Water-Soluble Polyaniline/Sm0.5Ba0.5Cu0.8Cr0.2O3+δfor NH3%水溶性聚苯胺/Sm0.5Ba0.5Cu0.8Cr0.2O3+δ材料的制备与氨敏性能研究

    Institute of Scientific and Technical Information of China (English)

    郝红霞; 米红宇; 柴琳琳

    2015-01-01

    The PANI/SBCC composites from water-soluble Polyaniline(PANI),prepared by chemical-oxide method and SmBaCu1-yCryO3+δ(y=0,0.1,0.2,0.3,0.4,0.5,0.6)(SBCC)powders,prepared by sol-gel method were analyzed through XRD,EDS,FT-IR spectra and TEM respectively. The composites were prepared by particle packing,and their sensitivities to NH3 under low temperature were studied. The results show that the sensitivities of PANI/SBCC materials to NH3 are superior to those of single PANI and SBCC under the same condition. At 60℃,the response of PANI/Sm0.5Ba0.5Cu0.8Cr0.2O3+δ(PANI/SBC80C20)reaches to 3.79 to NH3(volume fraction:100×10-6),and the re-sponse-recovery time is short.%采用化学氧化法制备了水溶性聚苯胺(PANI),用溶胶凝胶法制备了Sm0.5Ba0.5Cu1-yCryO3+δ(y=0,0.1,0.2,0.3,0.4,0.5, 0.6)(SBCC)粉体,用微粒填充法制备了PANI/SBCC复合材料.利用XRD、EDS、FT-IR、TEM多种手段对产物进行表征,研究其在较低工作温度下(60℃)对氨气的敏感性.结果表明,在同等条件下,在PANI元件、SBCC元件及PANI/SBCC元件中,PANI/Sm0.5Ba0.5Cu0.8Cr0.2O3+δ(PANI/SBC80C20)元件对NH3的气敏性能最优,对体积分数为100×10-6 NH3的灵敏度在60℃条件下达到最大值为3.79,且响应恢复时间短,还具有较好的选择性.

  14. Syntheses, Structure, Magnetism, and Optical Properties of the Ordered Interlanthanide Copper Chalcogenides Ln{sub 2}YbCuQ{sub 5} (Ln = La, Ce, Pr, Nd, Sm; Q = S, Se): Evidence for Unusual Magnetic Ordering in Sm{sub 2}YbCuS{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Geng Bang; Choi, Eun Sang; Guertin, Robert P.; Booth, Corwin H.; Albrecht-Schmitt, Thomas E.

    2010-11-19

    Ln{sub 2}YbCuQ{sub 5} (Ln = La, Ce, Pr, Nd, Sm; Q = S, Se) have been prepared by direct reaction of the elements in Sb{sub 2}Q{sub 3} (Q = S, Se) fluxes at 900 °C. All compounds have been characterized by single-crystal X-ray diffraction methods and they are isotypic. The structure of Ln{sub 2}YbCuQ{sub 5} consists of one-dimensional {sup 1}{sub {infinity}} [YbCuQ{sub 5}]{sup 6-} ribbons extending along the b axis that are connected by larger Ln{sup 3+} ions. Each ribbon is constructed from two single chains of [YbQ{sub 6}] octahedra with one double chain of [CuQ{sub 5}] trigonal bipyramids in the middle. All three chains connect with each other via edge-sharing. There are two crystallographically unique Ln atoms, one octahedral Yb site, and two disordered Cu positions inside of distorted Q{sub 5} trigonal bipyramids. Both Ln atoms are surrounded by eight Q atoms in bicapped trigonal prisms. The magnetic properties of Ln{sub 2}YbCuQ{sub 5} have been characterized using magnetic susceptibility and heat capacity measurements, while their optical properties have been explored using UV-vis-NIR diffuse reflectance spectroscopy. Cesub 2}YbCuSe{sub 5}, La{sub 2}YbCuS{sub 5}, Ce{sub 2}YbCuS{sub 5}, and Pr{sub 2}YbCuS{sub 5} are Curie-Weiss paramagnets. La{sub 2}YbCuSe{sub 5} and Nd{sub 2}YbCuS{sub 5} show evidence for short-range antiferromagnetic ordering at low temperatures. Sm{sub 2}YbCuS{sub 5} shows magnetic ordering at 5.9 K, followed by negative magnetization at low external fields. The band gaps of La{sub 2}YbCuSe{sub 5}, Ce{sub 2}YbCuSe{sub 5}, La{sub 2}YbCuS{sub 5}, Ce{sub 2}YbCuS{sub 5}, Pr{sub 2}YbCuS{sub 5}, Nd{sub 2}YbCuS{sub 5},and Sm{sub 2}YbCuS{sub 5} are 1.15 eV, 1.05 eV, 1.45 eV, 1.37 eV, 1.25 eV, 1.35 eV, and 1.28 eV respectively.

  15. Ce-Fe-modified zeolite-rich tuff to remove Ba(2+)-like (226)Ra(2+) in presence of As(V) and F(-) from aqueous media as pollutants of drinking water.

    Science.gov (United States)

    Olguín, María Teresa; Deng, Shuguang

    2016-01-25

    The sorption behavior of the Ba(2+)-like (226)Ra(2+) in the presence of H2AsO4(-)/HAsO4(2-) and F(-) from aqueous media using Ce-Fe-modified zeolite-rich tuff was investigated in this work. The Na-modified zeolite-rich tuff was also considered for comparison purposes. The zeolite-rich tuff collected from Wyoming (US) was in contact with NaCl and CeCl3-FeCl3 solutions to obtain the Na- and Ce-Fe-modified zeolite-rich tuffs (ZUSNa and ZUSCeFe). These zeolites were characterized by scanning electron microscopy and X-ray diffraction. The BET-specific surface and the points of zero charge were determined as well as the content of Na, Ce and Fe by neutron activation analysis. The textural characteristics and the point of zero charge were changed by the presence of Ce and Fe species in the zeolitic network. A linear model described the Ba(2+)-like (226)Ra(2+) sorption isotherms and the distribution coefficients (Kd) varied with respect to the metallic species present in the zeolitic material. The As(V) oxianionic chemical species and F(-) affected this parameter when the Ba(2+)-like (226)Ra(2+)-As(V)-F(-) solutions were in contact with ZUSCeFe. The H2AsO4(-)/HAsO4(2-) and F(-) were adsorbed by ZUSCeFe in the same amount, independent of the concentration of Ba(2+)-like (226)Ra(2+) in the initial solution.

  16. Preparation and Spectra Properties of BaO-Al2O3-P2O5-Sm2O3 System Protection Glasses

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The forming-regions of phosphate glasses doped with high Sm2O3 contents were studied by two step melting method. The relationship between absorption spectrum and rare earth contents was also discussed. The spectra of BASP glasses were measured by spectrophotometer. The results show that the forming regions will shrink with the increase of Al2O3 and it is difficult to form glass when [PO4]/[AlO4]<2. The forming regions tend to be a closed elliptical, and the intensity of characteristic absorption peak increases gradually with the increase of Sm2O3, the absorption lines broadens non-uniformly and there is approximate linear relation between optical density at the 1064 nm wavelength and Sm2O3 content.

  17. Improved activity and stability of Ni-Ce0.8Sm0.2O1.9 anode for solid oxide fuel cells fed with methanol through addition of molybdenum

    Science.gov (United States)

    Li, Ping; Yu, Baolong; Li, Jiang; Yao, Xueli; Zhao, Yicheng; Li, Yongdan

    2016-07-01

    Ni-Mo-Ce0.8Sm0.2O1.9 (SDC) composites are prepared and investigated as anodes of solid oxide fuel cells with methanol as fuel. The addition of Mo improves the catalytic activity for methanol pyrolysis and the resistance to carbon deposition of Ni-SDC anode. The anode with a mole ratio of Mo to Ni of 0.03:1 exhibits the lowest polarization resistance. The cell with that anode and SDC-carbonate composite electrolyte shows a maximum power density of 680 mW cm-2 at 700 °C. The stability of the cell is enhanced with the increase of the content of Mo in the anode, which is mainly attributed to the decreased amount of carbon deposits with a high graphitization degree.

  18. The stannides RE{sub 3}Au{sub 6}Sn{sub 5} (RE = La, Ce, Pr, Nd, Sm). Synthesis, structure, magnetic properties and {sup 119}Sn Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fickenscher, Thomas; Rodewald, Ute C.; Niehaus, Oliver; Gerke, Birgit; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Haverkamp, Sandra; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie

    2015-07-01

    The Ce{sub 3}Pd{sub 6}Sb{sub 5}-type rare earth stannides RE{sub 3}Au{sub 6}Sn{sub 5} (RE = La, Ce, Pr, Nd, Sm) were synthesized by arc-melting of the elements and subsequent annealing in open tantalum crucibles within sealed evacuated silica ampoules. The polycrystalline samples were studied by powder X-ray diffraction. The structures of three crystals were refined from single crystal X-ray diffractometer data: Pmmn, a = 1360.3(9), b = 455.9(2), c = 1023.6(4) pm, wR2 = 0.0275, 1069 F{sup 2} values, 48 variables for Ce{sub 3}Au{sub 6}Sn{sub 5}, a = 1352.4(4), b = 455.1(1), c = 1023.7(3) pm, wR2 = 0.0367, 1160 F{sup 2} values, 48 variables for Nd{sub 3}Au{sub 6}Sn{sub 5}, and a = 1339.8(2), b = 452.80(7), c = 1012.4(2) pm, wR2 = 0.1204, 1040 F{sup 2} values, 49 variables for Sm{sub 3}Au{sub 5.59(2)}Sn{sub 5.41(2)}. One of the gold sites of the samarium compound shows a significant degree of Au/Sn mixing. The RE{sub 3}Au{sub 6}Sn{sub 5} structures are composed of three-dimensional [Au{sub 6}Sn{sub 5}] polyanionic networks with the two crystallographically independent rare earth atoms in larger cages, i.e., RE1 rate at Au{sub 10}Sn{sub 6} and RE2 rate at Au{sub 8}Sn{sub 8}. The [Au{sub 6}Sn{sub 5}] network is stabilized by Au-Sn (266-320 pm), Au-Au (284-301 pm) as well as Sn-Sn (320 pm; distances given for the cerium compound) interactions. Temperature-dependent magnetic susceptibility measurements reveal an antiferromagnetic ordering only for Sm{sub 3}Au{sub 6}Sn{sub 5}, while the other compounds exhibit Curie-Weiss paramagnetism. {sup 119}Sn Moessbauer spectroscopy shows resonances in the typical range for intermetallic tin compounds where tin takes part in the polyanionic network [isomer shifts between 1.73(1) and 2.28(1) mm . s{sup -1}]. With the help of theoretical electric field gradient calculations using the WIEN2k code it was possible to resolve the spectroscopic contributions of all three crystallographically independent atomic tin sites in the {sup 119}Sn

  19. New orthorhombic derivative of CaCu{sub 5}-type structure: RNi{sub 4}Si compounds (R=Y, La, Ce, Sm, Gd–Ho), crystal structure and some magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Morozkin, A.V., E-mail: morozkin@general.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Knotko, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Yuan, Fang; Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India)

    2013-12-15

    The crystal structure of new YNi{sub 4}Si-type RNi{sub 4}Si (R=Y, La, Ce, Sm, Gd–Ho) compounds has been established using powder X-ray diffraction. The YNi{sub 4}Si structure is a new structure type, which is orthorhombic derivative of CaCu{sub 5}-type structure (space group Cmmm N 65, oC12). GdNi{sub 4}Si and DyNi{sub 4}Si compounds order ferromagnetically at 25 and 19 K, respectively whereas YNi{sub 4}Si shows antiferromagnetic nature. At 15 K, DyNi{sub 4}Si shows second antiferromagnetic-like transition. The magnetic moment of GdNi{sub 4}Si at 5 K in 50 kOe field is ∼7.2 μ{sub B}/f.u. suggesting a completely ordered ferromagnetic state. The magnetocaloric effect of GdNi{sub 4}Si is calculated in terms of isothermal magnetic entropy change and it reaches the maximum value of −12.8 J/kg K for a field change of 50 kOe near T{sub C} ∼25 K. - Graphical abstract: The RNi{sub 4}Si (R=Y, La, Ce, Sm, Gd–Ho) compounds crystallize in new YNi{sub 4}Si-type structure which is orthorhombic derivative of the basic CaCu{sub 5}-type structure. GdNi{sub 4}Si and DyNi{sub 4}Si compounds show the ferromagnetic-like ordering, whereas.YNi{sub 4}Si has the antiferromagnetic nature. The GdNi{sub 4}Si demonstrates the big magnetocaloric effect near temperature of ferromagnetic ordering. The relationship between initial CaCu{sub 5}-type DyNi{sub 5} and YNi{sub 4}Si-type DyNi{sub 4}Si lattices.

  20. Improving SiO2 impurity tolerance of Ce0.8Sm0.2O1.9: Synergy of CaO and ZnO in scavenging grain-boundary resistive phases

    Science.gov (United States)

    Ge, Lin; Ni, Qing; Cai, Guifan; Sang, Tianyi; Guo, Lucun

    2016-08-01

    Rapid oxygen ion conduction, which is important in solid oxide fuel cell (SOFC) electrolytes, is often dramatically hindered by the presence of even small concentrations of impurities such as SiO2, which is ubiquitous in ceramic processing. In this study, rapid degradation of the grain boundary (GB) conduction of Ce0.8Sm0.2O1.9 (SDC) is observed with increasing SiO2 addition from 0 to 1 wt%. Nearly complete GB conduction recovery is achieved through synergy between CaO and ZnO in the SDC + x wt% Si systems. Scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS) demonstrate the formation of a Ca-, Si-, and Sm-containing secondary phases, which is related to the enhancements in GB conductivity and reductions in activation energy. The scavenging effect of CaO is verified in this study and ZnO is observed to promote the scavenging reaction. Compared with the single-addition case (CaO/ZnO), the much higher SiO2 impurity tolerance of the combined system suggests the commercial potential of the "scavenger + promoter" strategy presented in this work.

  1. Preparation, spectroscopic and thermal characterization of new La(III), Ce(III), Sm(III) and Y(III) complexes of enalapril maleate drug. In vitro antimicrobial assessment studies

    Science.gov (United States)

    Refat, Moamen S.; Al-Azab, Fathi M.; Al-Maydama, Hussein M. A.; Amin, Ragab R.; Jamil, Yasmin M. S.

    2014-02-01

    The 1:1 M ratio metal complexes of enalapril maleate hypertensive drug with La(III), Ce(III), Sm(III) and Y(III) were synthesized. The suggested structures of the resulted complexes based on the results of elemental analyses, molar conductivity, (infrared, UV-visible and fluorescence) spectra, effective magnetic moment, thermal analysis (TG), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) were discussed. The infrared spectral data were suggested that enalapril reacts with metal ions as an ionic bidentate ligand through its carboxylate oxygen and the amide carbonyl oxygen, but in case of the Sm(III) complex, it reacted as a monodentate through its amide carbonyl oxygen. Maleate moiety acts with all these metals as bidentate ligand through its carboxylate or carbonyl oxygen. The kinetic and thermodynamic parameters such as: Ea, ΔH*, ΔS* and ΔG* were estimated from the DTG curves. The antibacterial evaluation of the enalapril maleate and their complexes were also performed against some gram positive and negative bacteria as well as fungi.

  2. Conductivity, transport number measurements and hydration thermodynamics of BaCe0.2Zr0.7Y(0.1 − ξ)NiξO(3 − δ)

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Bonanos, Nikolaos; Wang, Hsiang-Jen;

    2011-01-01

    BaCe0.2Zr0.7Y(0.1 − ξ)NiξO(3 − δ) compounds with ξ = 0.01 and 0.02 have been synthesized by solid state reaction at 1400 °C and sintered at 1450 °C. TEM analyses were performed and showed a segregation of nickel at the grain boundaries for ξ = 0.02. This apparent solubility limit of Ni in the B......-site of the perovskite is in agreement with similar data obtained earlier for the two compositions. The first aim of this work was to evaluate the conductivity of BaCe0.2Zr0.7Y(0.1 − ξ)NiξO(3 − δ) at temperature between 500 and 900 °C, using impedance spectroscopy at different oxygen partial pressures and water vapor...

  3. Water vapour solubility and conductivity study of the proton conductor BaCe(0.9 − x)ZrxY0.1O(3 − δ)

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Bonanos, Nikolaos; Caboche, G:

    2009-01-01

    in the sample. The direct current conductivity has been measured as a function of oxygen partial pressure, at a water vapour partial pressure of 0.015 atm. The total conductivity has been resolved into a p-type and an ionic component using a fitting procedure appropriate to the assumed defect model....... An estimation of the protonic component was made by assuming a conductivity isotope effect between 1.4 and 1.8. The total conductivity, obtained using impedance spectroscopy has been measured as a function of temperature in the water and heavy water exchanged states. The activation energy has been found to be 0......The perovskite BaCe(0.9 − x)ZrxY0.1O(3 − δ) has been prepared by solid state reaction at 1400 °C and conventional sintering at 1700 °C. Water uptake experiments performed between 400 and 600 °C, at a water vapour pressure of 0.02 atm, provide data on the concentration of protons incorporated...

  4. Rectification in (La,Sr)MnO3/(Ba,Sr)TiO3/(La,Ce)2CuO4 trilayer p-i-n junctions

    International Nuclear Information System (INIS)

    Oxide trilayer p-i-n junctions, with p-type La0.67Sr0.33MnO3 (LSMO) manganite layer and n-type La1.89Ce0.11CuO4 (LCCO) cuperate layer separated by Ba0.7Sr0.3TiO3 (BST) titanite insulator layer, have been deposited in situ and characterized. With the increment of the insulator layer thickness, the I-V characteristic of such p-i-n junctions changes from symmetric to asymmetric, and then to symmetric again, given the highest rectifying performance at the BST layer of about 25 nm thick. The largest asymmetry, defined as the ratio of dI/dV at +2 V and -2 V, respectively, is found >1000. The insulator layer thickness dependency indicates that the transport properties of the p-i-n junctions are dominated by the interplay between the interior fields at the LSMO/BST and BST/LCCO interfaces

  5. Hydrogen Permeation Performance of Ni-BaZr0.1Ce0.7Y0.2O3-δ Metal-Ceramic Hollow Fiber Membrane

    Institute of Scientific and Technical Information of China (English)

    Chun-li Yang; Qi-ming Xu; Zhi-wen Zhu; Wei Liu

    2012-01-01

    A dense Ni-BaZr0.1Ce0.7Y0.2O3-δ (BZCY) cermet hollow fiber is fabricated by sintering NiOBZCY hollow fiber precursors prepared by phase inversion method in 5%H2/95%Ar and its hydrogen permeation performance is investigated. The Ni-BZCY hollow fiber membrane possesses a "sandwich" structure.Finger-like structures are observed near both the inner and outer surfaces,while a dense layer is present in the center part.With 200 mL/min wet 20%H2/80%N2 on the shell side and 150 mL/min high purity Ar on the core side,the hydrogen permeation flux through the Ni-BZCY hollow fiber membrane at 900 ℃ is 0.53 μmol/cm2s.Owing to a high packing density,the hydrogen permeation flux per unit volume is greatly improved and membrane components composed of an assembly of hollow fibers may be applied in industrial hydrogen separation.

  6. Profile of yttrium segregation in BaCe{sub 0,9}Y{sub 0,1}O{sub 3-{delta}} as function of sintering temperature; Perfil da segregacao do itrio em BaCe{sub 0,9}Y{sub 0,1}O{sub 3-{delta}} em funcao da temperatura de sinterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Hosken, C.M.; Souza, D.P.F. de, E-mail: camila.hosken@gmail.co [Universidade Federal de Sao Carlos (LAPCEC/UFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais. Lab. de Preparacao e Caracterizacao Eletrica em Ceramicas

    2010-07-01

    Researches on solid oxide fuel cells indicate barium cerate perovskite as a very attractive material for using as electrolyte due to its high protonic conductivity. The objective of this work is investigate the yttrium segregation during sintering of BaCe{sub 0,9}Y{sub 0,1}O{sub 3-{delta}} doped with Zn O as a sintering aid. The powders were prepared by citrate process. Powders were isostatic pressed into pellets and sintered in air at 1200, 1275, 1325 and 1400 deg C. The samples were characterized by scanning electron microscopy, X-ray diffraction and impedance spectroscopy. Secondary phase containing Yttrium and Cerium was detected as sintering temperature increased. Increase of the lattice parameter and activation energy for electrical conductivity were also detected on samples sintered at 1400 deg C. (author)

  7. R{sub 4}Ir{sub 13}Ge{sub 9} (R=La, Ce, Pr, Nd, Sm) and RIr{sub 3}Ge{sub 2} (R=La, Ce, Pr, Nd): Crystal structures with nets of Ir atoms

    Energy Technology Data Exchange (ETDEWEB)

    Yarema, Maksym [Department of Inorganic Chemistry, Ivan Franko National University of Lviv, Kyryla i Mefodiya Str, 6, UA-79005 Lviv (Ukraine); Swiss Federal Laboratories for Materials Science and Technology (EMPA), Ueberlandstr. 129, CH-8600 Duebendorf (Switzerland); Zaremba, Oksana; Gladyshevskii, Roman [Department of Inorganic Chemistry, Ivan Franko National University of Lviv, Kyryla i Mefodiya Str, 6, UA-79005 Lviv (Ukraine); Hlukhyy, Viktor, E-mail: viktor.hlukhyy@lrz.tu-muenchen.de [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85747 Garching (Germany); Faessler, Thomas F. [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85747 Garching (Germany)

    2012-12-15

    The crystal structures of the new ternary compounds Sm{sub 4}Ir{sub 13}Ge{sub 9} and LaIr{sub 3}Ge{sub 2} were determined and refined on the basis of single-crystal X-ray diffraction data. They belong to the Ho{sub 4}Ir{sub 13}Ge{sub 9} (oP52, Pmmn) and CeCo{sub 3}B{sub 2} (hP5, P6/mmm) structure types, respectively. The formation of isotypic compounds R{sub 4}Ir{sub 13}Ge{sub 9} with R=La, Ce, Pr, Nd, and RIr{sub 3}Ge{sub 2} with R=Ce, Pr, Nd, was established by powder X-ray diffraction. The RIr{sub 3}Ge{sub 2} (R=La, Ce, Pr, Nd) compounds exist only in as-cast samples and decompose during annealing at 800 Degree-Sign C with the formation of R{sub 4}Ir{sub 13}Ge{sub 9}. The structure of Sm{sub 4}Ir{sub 13}Ge{sub 9} contains intersecting, slightly puckered nets of Ir atoms (4{sup 4})(4{sup 3}.6){sub 2}(4.6{sup 2}){sub 2} and (4{sup 4}){sub 2}(4{sup 3}.6){sub 4}(4.6{sup 2}){sub 2} that are perpendicular to [0 1 1] as well as to [0 -1 1] and [0 0 1]. The Ir atoms are surrounded by Ge atoms that form tetrahedra or square pyramids (where the layers intersect). The Sm and additional Ir atoms (in trigonal-planar coordination) are situated in channels along [1 0 0] (short translation vector). In the structure of LaIr{sub 3}Ge{sub 2} the Ir atoms form planar Kagome nets (3.6.3.6) perpendicular to [0 0 1]. These nets alternate along the short translation vector with layers of La and Ge atoms. - Graphical abstract: The crystal structures contain the nets of Ir atoms as main structural motif: R{sub 4}Ir{sub 13}Ge{sub 9} contains intersecting slightly puckered nets of Ir atoms, whereas in the structure of RIr{sub 3}Ge{sub 2} the Ir atoms form planar Kagome nets. Highlights: Black-Right-Pointing-Pointer The Ir-rich ternary germanides R{sub 4}Ir{sub 13}Ge{sub 9} (R=La, Ce, Pr, Nd, Sm) and RIr{sub 3}Ge{sub 2} (R=La, Ce, Pr, Nd) have been synthesized. Black-Right-Pointing-Pointer The RIr{sub 3}Ge{sub 2} compounds exist only in as-cast samples and decompose during annealing at 800

  8. Luminescence of Ce 3+ -Doped MB2Si2O8 (M = Sr, Ba): A Deeper Insight into the Effects of Electronic Structure and Stokes Shift

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Qi [Sun Yat-Sen Univ., Guangzhou, (China); Liu, Chunmeng [Sun Yat-Sen Univ., Guangzhou, (China); Hou, Dejian [Sun Yat-Sen Univ., Guangzhou, (China); Zhou, Weijie [Sun Yat-Sen Univ., Guangzhou, (China); Ma, Chong-Geng [Chongqing Univ. of Posts and Telecommunications (China); Liu, Guokui [Argonne National Lab. (ANL), Argonne, IL (United States); Brik, Mikhail G. [Chongqing Univ. of Posts and Telecommunications (China); Tao, Ye [Chinese Academy of Sciences (CAS), Beijing (China); Liang, Hongbin [Sun Yat-Sen Univ., Guangzhou, (China)

    2015-12-18

    A series of Sr 1 -2x CexNaxB2Si2O8 and Ba 1-2x CexKxB2Si2O8 (x = 0.005, 0.01, 0.02, 0.04, 0.06, 0.08) samples were synthesized by a high-temperature solid-state reaction. The low temperature excitation, emission, and fluorescence decay spectra together demonstrated that all spectral bands arise from the Ce 3+ ions located at only one kind of lattice site. The first-principles calculations of the structural and electronic properties of pure and Ce 3+2Si2O8 (M = Sr, Ba) were performed, and the obtained results were used for understanding the structural changes after doping and identification of the observed position of the host absorption bands. The measured 4f-5d excitation and emission spectra of Ce3+ ions doped in MB2Si2O8 were analyzed and simulated in the framework of the crystal-field (CF) theory. The electron-phonon coupling effect generally ignored in most studies published so far was also taken into account by applying the configurational coordinate model. The validity of such a combined insight into the 5d CF energy level positions and the Stokes shift has been confirmed by analyzing the dependence of the Ce 3+

  9. Experimental evidence of hydrogen–oxygen decoupled diffusion into BaZr0.6Ce0.25Y0.15O3−δ

    International Nuclear Information System (INIS)

    The electrical properties of BaZr0.6Ce0.25Y0.15O3−δ (BZCY) were studied as a function of both oxygen partial pressure (-2.65⩽log(PO2atm-1)⩽-0.62) and water vapor activity (-3.33⩽log(PH2Oatm-1⩽-1.3)) in the temperature range of 973–1073 K. The total conductivity slightly increased in reducing atmospheres with increasing water vapor activity because of the relative contribution to the total conductivity by the redox reaction at the given thermodynamic conditions. The partial conductivities of protons, holes and oxygen vacancies were successfully calculated, and the activation energy determined for proton transport was 0.3 ± 0.1 eV. The chemical diffusivity of oxygen at a fixed water vapor activity, D∼vO, could only be evaluated from Fick’s second law during oxidation and reduction at the fixed water vapor activity. However, twofold nonmonotonic conductivity relaxation behaviors were clearly confirmed in the temperature range investigated during hydration/dehydration. If PO2 represents the fixed oxygen partial pressure, D∼iH is the hydrogen chemical diffusivity at PO2 and D∼vH is the oxygen chemical diffusivity at PO2, it was observed that D∼iH>D∼vH at all experimental conditions, suggesting that the hydrogen chemical diffusion is always faster than oxygen on hydration/dehydration in the temperature range studied

  10. Crystal structure of R{sub 3}Ge{sub 1+x}Se{sub 7} (R = La, Ce, Pr, Sm, Gd and Tb, x = 0.43-0.49) and magnetic properties of Ce{sub 3}Ge{sub 1.47}Se{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Daszkiewicz, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, P.O. Box 1410, 50-950 Wroclaw (Poland); Strok, O.M. [Department of General and Inorganic Chemistry, Volyn National University, Voli Ave 13, 43009 Lutsk (Ukraine); Gulay, L.D. [Department of Ecology and Protection of Environment, Volyn National University, Voli Ave 13, 43009 Lutsk (Ukraine); Kaczorowski, D., E-mail: D.Kaczorowski@int.pan.wroc.p [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, P.O. Box 1410, 50-950 Wroclaw (Poland)

    2010-10-22

    Research highlights: {yields} Determination and refinement of the crystal structures of R{sub 3}Ge{sub 1+x}Se{sub 7} (R = La, Ce, Pr, Sm, Gd and Tb, x = 0.43-0.49) compounds from single-crystal X-ray diffraction data {yields} Determination of the magnetic behavior in single-crystalline Ce{sub 3}Ge{sub 1.47}Se{sub 7}. - Abstract: The crystal structures of ternary compounds R{sub 3}Ge{sub 1+x}Se{sub 7} (Dy{sub 3}Ge{sub 1.25}S{sub 7} structure type, space group P6{sub 3}, Pearson symbol hP22 + 2x, a = 10.7656(7) A, c = 6.0801(5) A, R1 = 0.0186 for La{sub 3}Ge{sub 1.48}Se{sub 7}; a = 10.684(1) A, c = 6.0611(8) A, R1 = 0.0257 for Ce{sub 3}Ge{sub 1.47}Se{sub 7}; a = 10.6408(9) A, c = 6.0548(7) A, R1 = 0.0290 for Pr{sub 3}Ge{sub 1.49}Se{sub 7}; a = 10.4419(7) A, c = 6.0283(6) A, R1 = 0.0201 for Sm{sub 3}Ge{sub 1.48}Se{sub 7}; a = 10.325(7) A, c = 6.0506(7) A, R1 = 0.0269 for Gd{sub 3}Ge{sub 1.45}Se{sub 7}; a = 10.2747(7) A, c = 6.0743(5) A, R1 = 0.0499 for Tb{sub 3}Ge{sub 1.43}Se{sub 7}) were determined by means of X-ray single-crystal diffraction. The R atoms occupy trigonal prisms capped with two additional atoms. The Ge atoms are located in octahedral and tetrahedral environment. The compound Ce{sub 3}Ge{sub 1.47}Se{sub 7} exhibits a Curie-Weiss type paramagnetic behavior due to the presence of fairly stable local magnetic moments on cerium ions. No hint at any magnetic phase transition was observed down to 1.72 K.

  11. Crystal structures of the R{sub 3}Mg{sub 0.5}GeS{sub 7} (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Huch, M.R. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine)]. E-mail: gulay@lab.univer.lutsk.ua; Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine); Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Ave 13, 43009 Lutsk (Ukraine)

    2006-11-09

    The crystal structures of the R{sub 3}Mg{sub 0.5}GeS{sub 7} (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er) compounds (La{sub 3}CuSiS{sub 7} structure type, space group P6{sub 3}, Pearson symbol hP23) were determined by means of X-ray powder diffraction: a = 0.9788(1) nm, c = 0.57745(5) nm, R {sub Bragg} = 0.0814 (Y{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 1.0262(2) nm, c = 0.57849(7) nm, R {sub Bragg} 0.0687 (Ce{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 1.01249(3) nm, c = 0.58040(2) nm, R {sub Bragg} = 0.0832 (Pr{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 1.00701(3) nm, c = 0.58047(3) nm, R {sub Bragg} = 0.0636 (Nd{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 0.99500(3) nm, c 0.57872(3) nm, R {sub Bragg} = 0.0870 (Sm{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 0.99319(3) nm, c = 0.57083(3) nm, R {sub Bragg} = 0.0901 (Gd{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 0.98007(5) nm, c = 0.57843(4) nm, R {sub Bragg} = 0.0859 (Tb{sub 3}Mg{sub 0.5}GeS{sub 7}); a 0.97698(4) nm, c = 0.57675(5) nm, R {sub Bragg} = 0.0931 (Dy{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 0.9735(2) nm, c = 0.57941(7) nm, R {sub Bragg} = 0.0763 (Ho{sub 3}Mg{sub 0.5}GeS{sub 7}); a = 0.9694(2) nm, c = 0.57994(7) nm, R {sub Bragg} 0.0724 (Er{sub 3}Mg{sub 0.5}GeS{sub 7}). The R-centered trigonal prisms, Mg-centered octahedra and Ge-centered tetrahedra can be selected in the crystal structure of the R{sub 3}Mg{sub 0.5}GeS{sub 7} compounds.

  12. Unprecedented CO2-promoted hydrogen permeation in Ni-BaZr0.1Ce0.7Y0.1Yb0.1O(3-δ) membrane.

    Science.gov (United States)

    Fang, Shumin; Brinkman, Kyle; Chen, Fanglin

    2014-01-01

    Conventional Ni-BaCeO3-based membranes possess high hydrogen permeation flux but suffer serious flux degradation in CO2-containing atmosphere because of the formation of BaCO3 insulating layer. In this work, we report a novel Ni-BaZr0.1Ce0.7Y0.1Yb0.1O(3-δ) (Ni-BZCYYb) membrane, capable of both high hydrogen permeation flux and stable performance in CO2-containing atmosphere at 900 °C. Most importantly, the flux is found to be promoted rather than being diminished by CO2 normally observed for other high temperature proton conductors. The flux enhancement in Ni-BZCYYb membrane is attributed to the increase of moisture content in feed gas. When CO2 is introduced, the reverse water-gas shift reaction takes place generating H2O and CO. This work demonstrates that CO2 can be beneficial rather than detrimental for hydrogen permeation membranes that possess high chemical stability. PMID:24328190

  13. Seleção de eletrodos para caracterização elétrica de Y-BaCeO3 contendo ZnO como aditivo de sinterização Electrode selection for electrical characterization of Y-BaCeO3 with ZnO as sintering aid

    Directory of Open Access Journals (Sweden)

    C. M. Hosken

    2012-09-01

    Full Text Available Neste trabalho é abordada a escolha da pasta de eletrodo para realização da caracterização elétrica de amostras de BaCeO3 dopado com ítrio e contendo ZnO como aditivo de sinterização. A sinterização ocorreu via fase líquida. Foi utilizada uma pasta de eletrodo de platina e outra de prata cujas temperaturas de cura são 1100 °C e 750 °C, respectivamente. A análise das interfaces amostra-eletrodo por microscopia eletrônica de varredura revelou que durante a cura da pasta de platina, devida a elevada temperatura, ocorreu exsudação de fase que permaneceu entre a superfície original da amostra e o eletrodo. Por conseqüência, durante a caracterização elétrica por espectroscopia de impedância foi detectada polarização adicional na interface amostra-eletrodo comprometendo a veracidade dos valores de resistividade elétrica do material em análise o que não ocorreu com o uso do eletrodo de prata devida sua menor temperatura de cura.This work deals with the choice of electrodes for realizing the electrical characterization of Yttrium doped-BaCeO3 sample which contains ZnO as sintering aid. The sintering occurred through liquid phase. It were used platinum and silver pastes which curing temperatures are 1100 °C and 750 °C, respectively. Scanning electron microscopy characterization of sample-electrode interfaces showed that during the curing of the platinum paste, due to the high temperature, occurred phase exudation which remained between the primary sample surface and electrode. Consequently, electrical characterization by impedance spectroscopy detected additional polarization at interface sample-electrode becoming non-veracious the electrical resistivity values of the material under analysis. No additional polarization was detected for silver electrodes due to the lowest curing temperature.

  14. Crystal structures of the R{sub 2}Pb{sub 3}Sn{sub 3}S{sub 12} (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gulay, L.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine)], E-mail: gulay@univer.lutsk.ua; Ruda, I.P. [Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine); Marchuk, O.V. [Department of Physical and Colloidal Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine); Olekseyuk, I.D. [Department of General and Inorganic Chemistry, Volyn State University, Voli Avenue 13, 43009 Lutsk (Ukraine)

    2008-06-12

    The crystal structures of the R{sub 2}Pb{sub 3}Sn{sub 3}S{sub 12} (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) compounds (space group Pmc2{sub 1}, Pearson symbol oP40, a = 0.38992 (1) nm, b = 2.01175 (7) nm, c = 1.15140 (4) nm, R{sub I} 0.0785 for Ho{sub 2}Pb{sub 3}Sn{sub 3}S{sub 12}) were investigated using X-ray powder diffraction. The R{sub 1} atoms are surrounded by trigonal prisms with two additional atoms, the R{sub 2} atoms by distorted octahedra with one additional atom. The Pb{sub 1} and Pb{sub 3} atoms are surrounded by trigonal prisms with one additional atom, the Pb{sub 2} atoms by trigonal prisms with two additional atoms. Octahedral surrounding exists for Sn{sub 1} and Sn{sub 2}. The Sn{sub 3} atoms are located in trigonal bipyramids. Four or five neighbours surround the S atoms.

  15. Defect Scheelite-Type Lanthanoid(III Ortho-Oxomolybdates(VI Ln0.667[MoO4] (Ln = Ce, Pr, Nd, and Sm and Their Relationship to Zircon and the NaTl-Type Structure

    Directory of Open Access Journals (Sweden)

    Ingo Hartenbach

    2011-12-01

    Full Text Available The rare-earth metal(III ortho-oxomolybdates with the formula Ln0.667[MoO4] (Ln = Ce, Pr, Nd, and Sm and defect scheelite-type structure crystallize in the tetragonal space group I41/a (a = 533–525, c = 1183–1158 pm with four formula units per unit cell. The Ln3+ cations at Wyckoff position 4b exhibit a coordination sphere of eight oxygen atoms in the shape of a trigonal dodecahedron. The same site symmetry (.. is observed for the tetrahedral oxomolybdate(VI entities [MoO4]2–, since their central Mo6+ cation is situated at the 4a position. Due to this equal site multiplicity, the lanthanoid(III cations have to be statistically under-occupied to maintain electroneutrality, thus a defect scheelite structure emerges. The partial structure of both the Ln3+ cations and the [MoO4]2– anions (if shrunk to their centers of gravity can be best described as distorted diamond-like arrangements. Therefore, these two interpenetrating partial structures exhibit a similar setup as found in the zircon-type as well as in the NaTl-type structure.

  16. Hydrothermal synthesis and structural characterization of a family of lanthanide tartrates: [Ln 2(C 4H 4O 6) 3(H 2O) 3]·1.5H 2O (Ln = La, Ce, Pr, Nd, Sm)

    Science.gov (United States)

    Athar, Muhammad; Li, Guanghua; Shi, Zhan; Chen, Yan; Feng, Shouhua

    2008-12-01

    Coordination polymers containing lanthanides with tartaric acid [Ln 2(C 4H 4O 6) 3(H 2O) 3]·1.5H 2O (Ln = La, Ce, Pr, Nd, Sm and C 4H 4O 6 = D(-) or L(+) tartrate anion) have been synthesized using hydrothermal techniques and characterized by single crystal X-ray diffraction. The compounds are all isotypic with a monoclinic crystal system in the P2 1/ n space group. The asymmetric units of coordination polymers contain two metal centers having different coordination environments. One metal is bonded to four tartrate groups having three D and one L isomers (or three L and one D isomers), whereas the other metal is bonded to five tartrate groups having two D and three L isomers (or two L and three D isomers). Each trivalent metal center is coordinated to nine oxygen atoms that originate from carboxylate and hydroxyl groups of the tartrate anions and water molecules. These new polymers have three-dimensional structures containing open channels that are occupied by non-coordinating water molecules. Thermogravimetric and differential thermal analyses and adsorption of nitrogen have also been studied for these compounds.

  17. LaCoO3: Promising cathode material for protonic ceramic fuel cells based on a BaCe0.2Zr0.7Y0.1O3−δ electrolyte

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Bonanos, Nikolaos; Lenrick, Filip;

    2012-01-01

    Symmetric cells (cathode/electrolyte/cathode) were prepared using BaCe0.2Zr0.7Y0.1O3−δ (BCZY27) as proton conducting electrolyte and LaCoO3 (LC) infiltrated into a porous BCZY27 backbone as cathode. Single phased LC was formed after annealing in air at 600 °C for 2 h. Scanning electron micrographs....... Two arcs correspond to the cathode contribution: a middle range frequency one (charge transfer) and a low frequency one (oxygen dissociation/adsorption). The area specific resistances (ASRs) of both contributions increase when decreasing the oxygen partial pressure. The low frequency arc...

  18. Vortex creep and critical current densities J c in a 2 μm thick SmBa2Cu3O7‑d coated conductor with mixed pinning centers grown by co-evaporation

    Science.gov (United States)

    Haberkorn, N.; Coulter, Y.; Condó, A. M.; Granell, P.; Golmar, F.; Ha, H. S.; Moon, S. H.

    2016-07-01

    We report the critical current densities J c and flux creep rates in a 2 μm thick SmBa2Cu3O7–δ coated conductor produced by co-evaporation. The sample presents strong pinning produced by correlated disorder (CD) (boundaries between growth islands, dislocations and twin boundaries) as well as random nanoparticles. Correlated pinning along the c-axis was evidenced due to the appearance of a large peak in the angular critical current, centered at H║c. The analysis of the critical current density J c (with the magnetic field applied parallel (H║c) and at 45° of the c-axis (H║45°)) indicates that CD assists pinning throughout the temperature range. For all temperatures and at both angles the in-field dependence of J c exhibits a power-law behavior. The contribution of CD drops when the field is rotated to intermediate angles between the c axis and a–b axis (i. e. H║45°), which derives in a reduction of the absolute J c value and poorer in-field dependences. The flux creep rate depends on the angle and its values remain approximately constant within the power-law regime. For H║c and H║45° and for magnetic fields lower than 20 kOe, the flux relaxation presents characterizing glassy exponents μ = 1.70 and μ = 1.32, respectively.

  19. Sm2O3掺杂Ce2O3的加入量对YBa2Cu3O7-δ界面性能的影响

    Institute of Scientific and Technical Information of China (English)

    夏红伟; 胡学飞

    2011-01-01

    Solid oxide fuel cell (SOFC) has many virtues such as high stability, long life, and low pollntion and so on, and is considered to be one of the green powers in twenty-one century. Currently, doped perovskite ABO3 materials are adopted as cathode material%固体氧化物燃料电池(SOFC)具有稳定性高、寿命长、污染低等优点,是二十一世纪的绿色能源之一。当前SOFC阴极通常采用掺杂的ABO3钙钛矿型材料。这类材料在高温下具有较高的导电率和催化活性,但中温化是SOFC的趋势,高温下常用的La(Sr)MnO3阴极材料在中温下性能下降,不能满足中温下电导率的要求。本论文尝试采用柠檬酸燃烧法来制备YBa2Cu3O7-δ,并在YBCO中加入一定量的Sm2O3掺杂的Ce2O3(SDC)作为SOFC的阴极材料,通过对阻抗分析,研究了SDC掺杂量、烧结温度等对该阴极材料性能的影

  20. Sm2O3掺杂Ce2O3的加入量对YBa2Cu3O7-δ界面性能的影响

    Institute of Scientific and Technical Information of China (English)

    夏红伟; 胡学飞

    2011-01-01

    固体氧化物燃料电池(SOFC)具有稳定性高、寿命长、污染低等优点,是二十一世纪的绿色能源之一.当前SOFC阴极通常采用掺杂的ABO3钙钛矿型材料.这类材料在高温下具有较高的导电率和催化活性,但中温化是SOFC的趋势,高温下常用的La(Sr)MnO3阴极材料在中温下性能下降,不能满足中温下电导率的要求.本论文尝试采用柠檬酸燃烧法来制备YBa2Cu3O7-δ,并在YBCO中加入一定量的Sm2O3掺杂的Ce2O3(SDC)作为SOFC的阴极材料,通过对阻抗分析,研究了SDC掺杂量、烧结温度等对该阴极材料性能的影响.实验结果表明:随着SDC的掺杂量x(0≤x≤50%)和烧结温度的升高,阴极材料的界面阻抗减小.在SDC的掺杂量为50%时,且在800℃下烧结得到的烧结体界面阻抗最小,其界面比电阻仅为0.1353ohm/c㎡(800℃).这标志着掺杂SDC的YBCO作为中温固体氧化物燃料电池的阴极材料时非常具有发展前景的.

  1. Preparation and characterization of the sup erlattice (Sm-doped ceria/yttria-stabilized zirconia)N electrolyte film%(Ce0.8Sm0.2O2-δ/Y2O3:ZrO2)N 超晶格电解质薄膜的制备及表征∗

    Institute of Scientific and Technical Information of China (English)

    刘华艳; 范悦; 康振锋; 许彦彬; 薄青瑞; 丁铁柱

    2015-01-01

    As is well known, a solid oxide fuel cell(SOFC) is a device that can convert chemical energy directly into electrical energy. The possibility to grow thin films of oxide materials is of great importance in the development of SOFC. Recently, it is expected that oxide heterostructures, with almost ideal interfaces, should lead to the interesting artificial materials with some novel properties. So we have prepared superlattice electrolyte thin films. On the MgO single-crystal substrates, multilayer epitaxial thin-film heterostructures of 20 mol% samarium-oxide-doped ceria (Ce0.8Sm0.2O2−δ, SDC) and 8 mol%yttria-stabilized zirconia (Y2O3: ZrO2YSZ) have been deposited in turn, using the pulsed laser deposition (PLD) technique. Five different superlattices (SDC/YSZ)N (N =3, 5, 10, 20, 30) films are fabricated, keeping the total thickness constant (300 nm), but with a different number of hetero-interfaces. The choice of coupling SDC and YSZ aims to have both layers in the superlattices made of oxygen-ion conductors with compatible crystallographic features. On one hand, we have to remove any potential contribution of the deposition substrate to the total conductivity, and the superlattices may be grown on ⟨110⟩-oriented MgO single-crystalline wafers. On the other hand, the YSZ electrolyte film requires that the temperature should be higher, and SDC as the electrolyte leakage;both should be combined with each other, so as to have complementary advantages. In this way, not only the temperature of SOFCs is reduced, but also the leakage avoided. Because YSZ and SDC both belong to cubic fluorite structure and have similar lattice parameters, the lattice constant of YSZ is 5.14 Å, and the lattice constant of SDC is 5.44 Å. Compatible crystal properties, oxygen ion conductivity, and great matching defects can lead to a semi-coherent interface between the ZrO2 and CeO2 layers. The interface effect is obvious. X-ray diffraction (XRD), high-resolution transmission electron

  2. Improvement in J{sub c} performance below liquid nitrogen temperature for SmBa{sub 2}Cu{sub 3}O{sub y} superconducting films with BaHfO{sub 3} nano-rods controlled by low-temperature growth

    Energy Technology Data Exchange (ETDEWEB)

    Miura, S., E-mail: miura-syun12@ees.nagoya-u.ac.jp; Yoshida, Y.; Ichino, Y.; Xu, Q. [Department of Energy Engineering and Science, Nagoya University, Nagoya 464-8603 (Japan); Matsumoto, K. [Department of Materials Science and Engineering, Kyushu Institute of Technology, Kitakyushu 804-8550 (Japan); Ichinose, A. [Electric Power Engineering Research Laboratory, Central Research Institute of Electric Power Industry, Yokosuka, Kanagawa 240-0196 (Japan); Awaji, S. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2016-01-01

    For use in high-magnetic-field coil-based applications, the critical current density (J{sub c}) of REBa{sub 2}Cu{sub 3}O{sub y} (REBCO, where RE = rare earth) coated conductors must be isotropically improved, with respect to the direction of the magnetic field; these improvements must be realized at the operating conditions of these applications. In this study, improvement of the J{sub c} for various applied directions of magnetic field was achieved by controlling the morphology of the BaHfO{sub 3} (BHO) nano-rods in a SmBCO film. We fabricated the 3.0 vol. % BHO-doped SmBCO film at a low growth temperature of 720 °C, by using a seed layer technique (T{sub s} = 720 °C film). The low-temperature growth resulted in a morphological change in the BHO nano-rods. In fact, a high number density of (3.1 ± 0.1) × 10{sup 3} μm{sup −2} of small (diameter: 4 ± 1 nm), discontinuous nano-rods that grew in various directions, was obtained. In J{sub c} measurements, the J{sub c} of the T{sub s} = 720 °C film in all directions of the applied magnetic field was higher than that of the non-doped SmBCO film. The J{sub c}{sup min} (6.4 MA/cm{sup 2}) of the former was more than 6 times higher than that (1.0 MA/cm{sup 2}) of the latter at 40 K, under 3 T. The aforementioned results indicated that the discontinuous BHO nano-rods, which occurred with a high number density, exerted a 3D-like flux pinning at the measurement conditions considered. Moreover, at 4.2 K and under 17 T, a flux pinning force density of 1.6 TN/m{sup 3} was realized; this value was comparable to the highest value recorded, to date.

  3. Crystal structure and magnetic properties of R{sub 3}Mn{sub 0.5}GeS{sub 7} (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er)

    Energy Technology Data Exchange (ETDEWEB)

    Daszkiewicz, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław (Poland); Marchuk, O.V. [Department of Inorganic and Physical Chemistry, Eastern European National University, Voli Ave 13, 43009 Lutsk (Ukraine); Gulay, L.D. [Department of Ecology and Protection of Environment, Eastern European National University, Voli Ave 13, 43009 Lutsk (Ukraine); Kaczorowski, D., E-mail: D.Kaczorowski@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław (Poland)

    2014-10-15

    Highlights: • Identification of two novel compounds Tb{sub 3}Mn{sub 0.5}GeS{sub 7} and Ho{sub 3}Mn{sub 0.5}GeS{sub 7}. • Refinement of crystal structures of ten R{sub 3}Mn{sub 0.5}GeS{sub 7} single-crystalline phases. • Finding of R and Mn contributions to magnetic behavior in R{sub 3}Mn{sub 0.5}GeS{sub 7} phases. - Abstract: The crystal structures of quaternary R{sub 3}Mn{sub 0.5}GeS{sub 7} (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er) compounds of La{sub 3}Mn{sub 0.5}SiS{sub 7} structure type (space group P6{sub 3}, Pearson symbol hP23) were determined by means of single crystal X-ray diffraction. The R atoms occupy trigonal prisms with two additional atoms, the Mn atoms are located in octahedra, while the Ge atoms are located in tetrahedra. Magnetic studies were performed on polycrystalline samples of Y{sub 3}Mn{sub 0.5}GeS{sub 7}, Pr{sub 3}Mn{sub 0.5}GeS{sub 7} and Dy{sub 3}Mn{sub 0.5}GeS{sub 7}. The former compound is a Curie–Weiss paramagnet due to magnetic moments carried on trivalent Mn ions. The other ones exhibit localized paramagnetic behavior due to both Mn{sup 3+} and R{sup 3+} sublattices. While the Dy-bearing sulfide orders antiferromagnetically below 5.5 K, no unambiguous indication of any magnetic ordering in Y{sub 3}Mn{sub 0.5}GeS{sub 7} and Pr{sub 3}Mn{sub 0.5}GeS{sub 7} was found down to 1.72 K.

  4. Separation of Red(Y_2O_3:Eu~(3+)),Blue(BaMgAl_(10)O_(17):Eu~(2+))and Green(CeMgAl_(10)O_(17):Tb)Rare Earth Phosphors by Liquid/Liquid Extraction

    Institute of Scientific and Technical Information of China (English)

    MEI Guangjun; RAO Peng; Mitsuaki Matsuda; Toyohisa Fujita

    2009-01-01

    A novel process for separation of red(Y_2O_3:Eu~(3+)),blue(BaMgAl_(10)O_(17):Eu~(2+))and green(CeMgAl_(10)O_(17):Tb~3)rare earth fluorescent powders was proposed.At first,the blue powder can be extracted selectively from an aqueous solution using a chelating collector 2-thenoyltrifluoroacetone (TTA)dissolved in heptane at alkaline pH condition,then,chloroform was used for extracting the green powder into organic phase.The red phosphor remains in aqueous phase with potassium sodium tartrate depressant(PST).Therefore,three phosphors can be separated successfully from their artificial mixtures by liquid/liquid extraction,and grades and recovery of separated products reach respectively as follows:red is 96.9%and 95.2%,blue is 82.7%and 98.8%,green is 94.6%and 82.6%.

  5. Pinning Properties of PLD (NdxSmxGd1−2x)Ba2Cu3O7−δ Thin films

    DEFF Research Database (Denmark)

    Li, Xiaofen; Grivel, Jean-Claude; Yue, Zhao;

    2012-01-01

    The self field critical current density, flux relaxation rate and accommodation field is studied in ternary rare earth (RE) barium cuprate thin films made by PLD on STO, with RE=Nd, Sm and Gd. By systematically changing the substitution level of Nd and Sm in GdBCO films, we found that the accommo......The self field critical current density, flux relaxation rate and accommodation field is studied in ternary rare earth (RE) barium cuprate thin films made by PLD on STO, with RE=Nd, Sm and Gd. By systematically changing the substitution level of Nd and Sm in GdBCO films, we found...

  6. Thermal evolution of the crystal structure of proton conducting BaCe0.8Y0.2O3-δ from high-resolution neutron diffraction in dry and humid atmosphere.

    Science.gov (United States)

    Eriksson Andersson, Annika K; Selbach, Sverre M; Grande, Tor; Knee, Christopher S

    2015-06-21

    The crystal structure of the proton conducting perovskite BaCe(0.8)Y(0.2)O(3-δ) (BCY20) has been studied via high-resolution in situ neutron diffraction performed in controlled dry and humid (heavy water) oxygen flow. Two phase transitions, cubic Pm3[combining macron]m→R3[combining macron]c (775 °C)→Imma (250 °C) were observed on cooling from 1000 °C in dry O(2). A significant shift of the phase stability fields was observed on cooling in wet oxygen (pD(2)O ≈ 0.2 atm) with the R3[combining macron]c structure stabilised at 900 °C, and the R3[combining macron]c→Imma transition occurring at 675 °C. On cooling below 400 °C a monoclinic, I2/m, phase started to appear. The structural dependence on hydration level is primarily due to the de-stabilisation of the correlated, octahedra tilts as a consequence of structural relaxation around the oxygen vacancies present in the non-hydrated phase. The tendency of hydrated BaCe(0.8)Y(0.2)O(3-δ) to show octahedral tilting is also found to be enhanced, indicating that the deuteronic (protonic) defects influence the crystal structure, possibly via hydrogen bonding. Stabilisation of the monoclinic I2/m phase is attributed to the structural effect of deuterons that is inferred to increase on cooling as deuterons localise to a greater extent. Changing from wet oxidising (O(2) + D2O(g)) to wet reducing (5% H2 in Ar + D2O(g)) atmosphere did not influence the structure or the phase stability, indicating that Ce(4+) was not reduced under the present conditions. Based on the observed cell volume expansion protonic defects are present in the material at 900 °C at a D(2)O partial pressure of ∼0.2 atm. The origin of the chemical expansion is explained by the effective size of the oxygen vacancy being significantly smaller than the [OD] defect. Rietveld analysis has been used to locate possible sites for the deuterons in the high temperature, R3[combining macron]c and Imma, phases that are most relevant for proton transport

  7. Studies on Structural and Morphological Properties of Multidoped Ceria Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-δ (x=0.2 as Solid Solutions

    Directory of Open Access Journals (Sweden)

    Marija Stojmenović

    2016-01-01

    Full Text Available The nanopowdery solid solutions of multidoped ceria Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095O2-δ (x=0.2 with the fluorite type crystal structure of CeO2 were synthesized for the first time. Two synthesis procedures were applied: the modified glycine-nitrate procedure (MGNP method and room temperature self-propagating reaction (SPRT method. All nanopowders were characterized by XRPD analysis, Raman spectroscopy, low temperature nitrogen physisorption, TEM, and SEM methods. According to the XRPD and Raman spectroscopy results, single phase solid solutions of fluorite structure were evidenced regardless of the number of dopants and synthesis procedure. Both XRPD and TEM were analyses evidenced nanometer particle dimensions. The SPRT method results in obtaining sample with higher specific surface area, smaller crystallite and particles sizes, and the same values of the lattice parameter in comparison to pure CeO2. Raman spectroscopy was confirmed to the oxygen vacancies introduced into the ceria lattice when Ce4+ ions were replaced with cations (dopants of lower valence state (3+, which may indicate the potential improvement of ionic conductivity. Additionally, the presence of oxygen vacancies in the lattice ceria, as well as very developed grain boundaries, gives a new possibility for potential application of obtained nanopowders in the area of room temperature ferromagnetism as spintronics.

  8. Studies on Structural and Morphological Properties of Multidoped Ceria Ce 0.8 Nd 0.0025 Sm 0.0025 Gd 0.005 Dy 0.095 Y 0.095 O 2 - δ ( x = 0.2 ) as Solid Solutions

    KAUST Repository

    Stojmenović, Marija

    2016-04-17

    The nanopowdery solid solutions of multidoped ceria Ce0.8Nd0.0025Sm0.0025Gd0.005Dy0.095Y0.095 () with the fluorite type crystal structure of CeO2 were synthesized for the first time. Two synthesis procedures were applied: the modified glycine-nitrate procedure (MGNP method) and room temperature self-propagating reaction (SPRT method). All nanopowders were characterized by XRPD analysis, Raman spectroscopy, low temperature nitrogen physisorption, TEM, and SEM methods. According to the XRPD and Raman spectroscopy results, single phase solid solutions of fluorite structure were evidenced regardless of the number of dopants and synthesis procedure. Both XRPD and TEM were analyses evidenced nanometer particle dimensions. The SPRT method results in obtaining sample with higher specific surface area, smaller crystallite and particles sizes, and the same values of the lattice parameter in comparison to pure CeO2. Raman spectroscopy was confirmed to the oxygen vacancies introduced into the ceria lattice when Ce4+ ions were replaced with cations (dopants) of lower valence state (3+), which may indicate the potential improvement of ionic conductivity. Additionally, the presence of oxygen vacancies in the lattice ceria, as well as very developed grain boundaries, gives a new possibility for potential application of obtained nanopowders in the area of room temperature ferromagnetism as spintronics.

  9. Power-law index and penetration depth of (NdxSmxGd1−2x)Ba2Cu3O7−δ films studied by AC susceptibility

    DEFF Research Database (Denmark)

    Li, Xiaofen; He, Dong; Grivel, Jean-Claude

    2012-01-01

    Superconducting (NdxSmxGd1−2x)Ba2Cu3O7−δ films with x=0, 0.1, 0.25, 0.33 were grown by PLD on STO single crystal substrates. The power-law index n and penetration depth λ are studied by AC susceptibility. During cooling, n in films with x ≠ 0 increases much slower compared with the films with x = 0....... The films with x ≠ 0 also tend to have a longer penetration depth. These properties might be related to the higher possibility for disorder in the mixed (Nd,Sm,Gd)BCO films....

  10. Nitrato-complexes of Y(III), La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl) benzimidazole

    International Nuclear Information System (INIS)

    The nitrato-complexes, [Y(PyBzH)2(NO3)2]NO3.H2O and Nd, Sm, Gd, Tb, Dy, Ho ; n=1-3, m=0-0.5 ; PyBzh=2-(2 -pyridyl)benzimidazole] are formed on interaction of the ligand with metal nitrates in ethanol. The electrical conductance values (116-129 ohm-1cm2mol-1) suggest 1:1 electrolyte-nature of the complexes. Magnetic moment values of Ce(2.53 B.M.), Pr(3.62 B.M.), Nd(3.52 B.M.), Sm(1.70 B.M.), Gd(8.06 B.M.), Tb(9.44 B.M.), Dy(10.56 B.M.) and Ho(10.51 B.M.) in the complexes confirm the terpositive state of the metals. Infrared evidences are obtained for the existance of both coordinated (C2v) and uncoordinated (D3h) nitrate groups. Electronic absorption spectra of Pr(III)-, Nd(III)-, Sm(III)-, Tb(III)-, Dy(III)- and Ho(III)-complexes have been analysed in the light of LSJ terms. (author)

  11. Surface exchange kinetics and chemical diffusivities of BaZr{sub 0.2}Ce{sub 0.65}Y{sub 0.15}O{sub 3−δ} by electrical conductivity relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Dae-Kwang; Jeon, Sang-Yun; Singh, Bhupendra [Ionics Lab, School of Materials Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwang-Ju 500-757 (Korea, Republic of); Park, Jun-Young [Department of Advanced Materials Engineering, Sejong University, Seoul 143-747 (Korea, Republic of); Song, Sun-Ju, E-mail: song@chonnam.ac.kr [Ionics Lab, School of Materials Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwang-Ju 500-757 (Korea, Republic of)

    2014-10-15

    Highlights: • Electrical conductivity relaxation in BaCe{sub 0.65}Zr{sub 0.2}Y{sub 0.15}O{sub 3−δ} was monitored. • Monotonic relaxation behavior was observed during oxidation/reduction. • Nonmonotonic twofold relaxation behavior was observed during hydration/dehydration. • Surface exchange coefficients and diffusivities of O and H were calculated. - Abstract: Perovskite-type oxide BaCe{sub 0.65}Zr{sub 0.2}Y{sub 0.15}O{sub 3−δ} (BCZY2015) was synthesized by a solid state reaction method. BCZY2015 samples were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The time dependent variation in electrical conductivity of BCZY2015 was monitored during the oxidation/reduction in oxygen partial pressure (pO{sub 2}) range of −2.28 ⩽ log (pO{sub 2}/atm) ⩽ −0.68 at a fixed water vapor pressure (pH{sub 2}O), and during the hydration/dehydration in −3.15 ⩽ log (pH{sub 2}O/atm) ⩽ −2.35 range in air. The electrical conductivity showed a monotonic relaxation behavior by the ambipolar diffusion of V{sub o}{sup ··} and OH{sub o}{sup ·} during the oxidation/reduction and the relaxation process was governed by the diffusivity of oxygen (D-tilde{sub vO}). On the other hand, during the hydration/dehydration process, a non-monotonic twofold relaxation behavior was observed due to the decoupled diffusion of H and O components with the mediation of holes, and the conductivity relaxation process was governed by the diffusivities of both H (D-tilde{sub iH}) and O (D-tlde{sub vH}). The values of surface exchange coefficients and diffusivities of oxygen and hydrogen were calculated from Fick’s second law by the nonlinear least squares fitting of the conductivity data, as proposed by Yoo et al. (2008)

  12. Analysis of the melting temperatures of RT2 compounds (MgCu2 structure) (R=Rare Earth, T=Mn,Fe,Co,Ni,Ru,Rh,Pd,Os,Ir,Pt) and RT2X2 compounds (R=La,Ce,Sm,Er; T=Mn,Fe,Co,Ni,Cu,Ru,Rh,Pd,Pt; X=Si,Ge)

    International Nuclear Information System (INIS)

    Physico-chemical analysis techniques, including X-ray phase analysis and differential thermal analysis were employed for the characterisation of compounds including their melting temperature. The melting temperature for 70 RT2X2 compounds has been measured (R=(La, Ce, Sm, Er, Tm), T=(Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Pt), X=(Si, Ge)). It is established, that the compounds CePt2Ge2, LaPt2Si2, LaPt2Ge2 belong to the CaBe2Ge2 structure type (group P4/mmm): LaPt2Si2 (a=0.4280(2) nm, c=0.9831(6) nm); LaPt2Ge2 (a=0.4417(3) nm, c=0.976(2) nm) and CePt2Ge2 (a=0.44033(4) nm, c=0.9808(1)). An empirical model able to describe the melting temperature of Tm of the compounds RT2, RT2X2 with accuracy often better than 5% is presented: Tm=const/V1/3, where the constant factor depends on the type of atoms constituting the compound, and where V is unit cell volume. (orig.)

  13. A high temperature study on thermodynamic, thermal expansion and electrical properties of BaCe0.4Zr0.4Y0.2O3-δ proton conductor

    Science.gov (United States)

    Basbus, J. F.; Arce, M. D.; Prado, F. D.; Caneiro, A.; Mogni, L. V.

    2016-10-01

    BaCe0.4Zr0.4Y0.2O3-δ (BCZY) was synthesized by solid state reaction, calcined and sintered at 1600 °C for 12 h. Crystal structure was studied by X-ray diffraction (XRD). Morphology and porosity were determined by scanning electron microscopy (SEM). Crystalline structure, oxygen non-stoichiometry, linear expansion and electrical conductivity were characterized under oxidizing and reducing atmosphere by high temperature X-ray diffraction (HT-XRD), thermogravimetry (TG), dilatometry, and electrochemical impedance spectroscopy (EIS), respectively. Chemical stability under CO2-rich atmosphere was evaluated by TG. BCZY electrical conductivity was studied by EIS under O2-containing atmosphere with water vapor (2% H2O) and heavy water vapor (2% D2O) in order to evaluate protonic conductivity. Throughout these techniques, interstitial proton incorporation/loss was observed under oxidizing and reducing atmosphere, between 300 and 500 °C. The conductivity presents two contributions. The bulk conductivity at high frequencies takes the same value regardless wet oxidizing or reducing atmosphere, decreasing its value in presence of D2O vapor supporting H-conductivity. On the other hand, the grain boundary conductivity was strongly dependent on the nature of wet atmosphere.

  14. Structural, thermal and microstructural studies of the proton conductor BaCe0.7Zr0.1Y0.05Zn0.15O3 for IT-SOFCs

    Science.gov (United States)

    Hossain, S.; Radenahmad, N.; Zaini, J. H.; Begum, F.; Azad, A. K.

    2016-03-01

    The specimen of BaCe0.7Zr0.1Y0.05Zn0.15O3, a perovskite-type electrolyte, has been synthesized for application in an anode-supported protonic solid oxide fuel cell by the conventional solid state reaction in air at 1200°C for 12 hours. Structural and thermal characterization has been performed using room temperature X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). Rietveld analysis of the XRD data has been analyzed by FullProf program and confirmed the single phase of the sample with an orthorhombic crystal structure in the Pbnm space group. To understand the temperature dependent behaviour TG/DTA scan of the precursor was recorded. The TG/DTA scan was performed under constant flow of Argon which exhibits a gradual weight loss up to 900oC. The SEM image of the pellet surface of the sample shows that the sample sintered at 1200oC was dense and suitable to use as electrolyte in solid oxide fuel cells (SOFCs).

  15. Crystal grains alignment of SmBCO film by advanced TFA-MOD method

    International Nuclear Information System (INIS)

    We grew SmBa2Cu3O7-y (SmBCO) films on LaAlO3 (LAO) single crystalline substrates by an advanced TFA-MOD method and discussed the effects of process conditions such as oxygen partial pressure in the crystallization step on the crystal grains alignment of SmBCO film. Oxygen partial pressure affected strongly on the orientation of SmBCO film. Formation of a-axis crystal grains of the SmBCO was suppressed, and, at the same time, c-axis crystal grains of the SmBCO increased with decreasing the oxygen concentration

  16. Fabrication of 5 cm long epitaxial Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} single buffer layer on textured Ni-5%W substrate for YBCO coated conductors via dip-coating PACSD method

    Energy Technology Data Exchange (ETDEWEB)

    Lei, M.; Wang, W.T.; Pu, M.H.; Yang, X.S.; He, L.J. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [Science and Engineering, University of New South Wales, Sydney 2052, New South Wales (Australia); Zhao, Y., E-mail: yzhao@home.swjtu.edu.cn [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)] [Science and Engineering, University of New South Wales, Sydney 2052, New South Wales (Australia)

    2011-11-15

    Epitaxial Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} single buffer layer for YBCO coated conductors was deposited via fluorine-free dip-coating CSD. Flat, dense and crack-free SCO films with sharp (2 0 0) c-axis texture were obtained by carefully controlling the processing. YBCO thin films with a homogeneous surface microstructure were deposited on the SCO-buffered NiW substrate via CSD approach. Five centimeters long epitaxial Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} (SCO) single buffer layer for YBCO coated conductors was deposited via dip-coating polymer-assisted chemical solution deposition (PACSD) approach on bi-axially textured Ni-5%W (2 0 0) alloy substrate. The film formation and texture evolution were investigated using X-ray diffraction and scanning electron microscopy. Flat, dense and crack-free SCO films with sharp (2 0 0) c-axis texture were obtained by way of carefully controlling the concentration of precursor solution, withdrawing speed, annealing temperature and dwelling time. On consideration of both microstructure and texture, epitaxial SCO single buffer layers were fabricated using precursor solution of 0.3 M cationic concentration, the withdrawing speed of 10 mm/min and heat treatment at 1100 deg. C in Ar-5%H{sub 2} mixture gas for 0.5 h. Epitaxial YBCO thin films with a homogeneous surface microstructure were deposited on the SCO-buffered NiW substrate via dip-coating PACSD approach. The PACSD approach was a promising way to fabricate long and low-cost YBCO coated conductors.

  17. A magnetic study of ThCr2Si2-type pseudo-ternary RMn1.5T0.5Ge2 compounds. (R=Y,Ce-Sm,Gd-Ho; T=Fe,Cu)

    International Nuclear Information System (INIS)

    We report on bulk magnetization measurements performed on ThCr2Si2-type RMn1.5T0.5Ge2 compounds (R=Y, La-Nd, Sm, Gd-Ho; T=Cu, Fe). These pseudo-ternary compounds display largely correlated variations of their magnetic transition temperatures. This phenomenon might be related to magnetic properties based on competing in-plane and inter-plane Mn-Mn interactions. The RMn1.5Cu0.5Ge2 compounds are characterized by relatively large magnetocrystalline anisotropy. (orig.)

  18. $\\gamma$-soft $^{146}$Ba and the role of non-axial shapes at N ~ 90

    CERN Document Server

    Mitchell, A J; McCutchan, E A; Albers, M; Ayangeakaa, A D; Bertone, P F; Carpenter, M P; Chiara, C J; Chowdhury, P; Clark, J A; Copp, P; David, H M; Deo, A Y; DiGiovine, B; D'Olympia, N; Dungan, R; Harding, R D; Harker, J; Hota, S S; Janssens, R V F; Kondev, F G; Liu, S H; Ramayya, A V; Rissanen, J; Savard, G; Seweryniak, D; Shearman, R; Sonzogni, A A; Tabor, S L; Walters, W B; Wang, E; Zhu, S

    2015-01-01

    Low-spin states in the neutron-rich, N = 90 nuclide $^{146}$Ba were populated following $\\beta$-decay of $^{146}$Cs, with the goal of clarifying the development of deformation in Ba isotopes through delineation of their non-yrast structures. Fission fragments of $^{146}$Cs were extracted from a 1.7-Ci $^{252}$Cf source and mass-selected using the CARIBU facility. Low-energy ions were deposited at the center of a box of thin $\\beta$ detectors, surrounded by a high-efficiency HPGe array. The new $^{146}$Ba decay scheme now contains 31 excited levels extending up to ~2.5 MeV excitation energy, double what was previously known. These data are compared to predictions from the Interacting Boson Approximation (IBA) model. It appears that the abrupt shape change found at N = 90 in Sm and Gd is much more gradual in Ba and Ce, due to an enhanced role of the $\\gamma$ degree of freedom.

  19. Study on new BaCe{sub 0.7}In{sub 0.3}O{sub 3−δ}–Gd{sub 0.1}Ce{sub 0.9}O{sub 2−δ} composite electrolytes for intermediate-temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fengguang; Dang, Junjie; Hou, Jie; Qian, Jing; Zhu, Zhiwen; Wang, Zhongtao [CAS Key Laboratory of Materials for Energy Conversion, Department of Material Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Liu, Wei, E-mail: wliu@ustc.edu.cn [CAS Key Laboratory of Materials for Energy Conversion, Department of Material Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-08-05

    Highlights: • New BCI–GDC composite electrolytes were synthesized using a one-step method for SOFCs. • The sintering temperature decreases as the BCI content increases. • The conductivity and OCV values enhanced as the GDC content increases. • The possible interface effects between BCI and GDC were analyzed. - Abstract: New mixed ionic conductors, BaCe{sub 0.7}In{sub 0.3}O{sub 3−δ}–Gd{sub 0.1}Ce{sub 0.9}O{sub 2−δ} (BCI–GDC, weight ratio, 3:7, 5:5 and 7:3), were synthesized via a one-step citric acid–nitrate gel combustion method as electrolyte materials for solid oxide fuel cells (SOFCs). X-ray diffraction patterns of BCI–GDC indicated that there was no impurity phase formed after sintering at high temperature up to 1400 °C. Scanning electron microscopic study of BCI–GDC depicted dense grain morphology. Single fuel cells were prepared and the corresponding electrochemical performances were tested. The sintering temperature of the dense composite electrolyte membranes decrease as the BCI content increases because of the sintering aids of In element. All samples with the composite electrolyte showed higher open circuit voltage (OCV) values than the single phase GDC. In addition, Electrical conductivity of the composite electrolyte under different atmospheres at different temperatures confirmed that the BCI–GDC exhibited high mixed oxygen ionic and protonic conduction. The test results indicated that the conductivity and OCV values of the composite electrolyte enhanced as the GDC content increases, and the optimum performance was found to be BCI3–GDC7 compared with the pure BCI and GDC electrolyte. The possible interface effects were suggested to explain this phenomenon. Our results not only provide one new promising composite electrolyte material for intermediate-temperature SOFCs but the composition dependence can actually provide a guide for the material design, optimization.

  20. Influence of foreign cations (Zr4+, La3+, Pr3+ and Sm3+) on CuO-CeO2: microwave induced solution combustion synthesis, characterization and CO oxidation activity

    International Nuclear Information System (INIS)

    Carbon monoxide treatment by catalytic oxidation, such as water-gas-shift reaction (WGSR), preferential oxidation of CO in H2 rich streams (PROX) and its simple oxidation have received a great attention by the scientific community. The noble metal-based nanocomposites have proven to be the highly effective candidates towards the CO oxidation. However, some of the disadvantages associated with the noble metals leads to an extensive search for alternative materials. In recent years, copper-cerium based mixed oxides have received much attention because they are inexpensive, environmentally benign and can be prepared easily. Therefore, the present study was aimed at developing a new class of copper promoted metal doped CeO2 catalysts using microwave-assisted combustion method

  1. Single crystals of LnFeAsO{sub 1-x}F{sub x} (Ln = La, Pr, Nd, Sm, Gd) and Ba{sub 1-x}Rb{sub x}Fe{sub 2}As{sub 2}: Growth, structure and superconducting properties

    Energy Technology Data Exchange (ETDEWEB)

    Karpinski, J., E-mail: karpinski@phys.ethz.c [Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich (Switzerland); Zhigadlo, N.D.; Katrych, S.; Bukowski, Z.; Moll, P. [Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich (Switzerland); Weyeneth, S.; Keller, H. [Physik-Institut der Universitaet Zuerich, 8057 Zuerich (Switzerland); Puzniak, R. [Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland); Tortello, M.; Daghero, D.; Gonnelli, R. [Dipartimento di Fisica, Politecnico di Torino, 10129 Torino (Italy); Maggio-Aprile, I. [DPMC-MaNEP, University of Geneva, Geneva (Switzerland); Fasano, Y. [DPMC-MaNEP, University of Geneva, Geneva (Switzerland); Low Temperatures Laboratory and Instituto Balseiro, Bariloche (Argentina); Fischer, O. [DPMC-MaNEP, University of Geneva, Geneva (Switzerland); Rogacki, K. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wroclaw, P.O. Box 1410 (Poland); Batlogg, B. [Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich (Switzerland)

    2009-05-01

    A review of our investigations on single crystals of LnFeAsO{sub 1-x}F{sub x} (Ln = La, Pr, Nd, Sm, Gd) and Ba{sub 1-x}Rb{sub x}Fe{sub 2}As{sub 2} is presented. A high-pressure technique has been applied for the growth of LnFeAsO{sub 1-x}F{sub x} crystals, while Ba{sub 1-x}Rb{sub x}Fe{sub 2}As{sub 2} crystals were grown using a quartz ampoule method. Single crystals were used for electrical transport, structure, magnetic torque and spectroscopic studies. Investigations of the crystal structure confirmed high structural perfection and show incomplete occupation of the (O, F) position in superconducting LnFeAsO{sub 1-x}F{sub x} crystals. Resistivity measurements on LnFeAsO{sub 1-x}F{sub x} crystals show a significant broadening of the transition in high magnetic fields, whereas the resistive transition in Ba{sub 1-x}Rb{sub x}Fe{sub 2}As{sub 2} simply shifts to lower temperature. The critical current density for both compounds is relatively high and exceeds 2 x 10{sup 9} A/m{sup 2} at 15 K in 7 T. The anisotropy of magnetic penetration depth, measured on LnFeAsO{sub 1-x}F{sub x} crystals by torque magnetometry is temperature dependent and apparently larger than the anisotropy of the upper critical field. Ba{sub 1-x}Rb{sub x}Fe{sub 2}As{sub 2} crystals are electronically significantly less anisotropic. Point-Contact Andreev-Reflection spectroscopy indicates the existence of two energy gaps in LnFeAsO{sub 1-x}F{sub x}. Scanning Tunneling Spectroscopy reveals in addition to a superconducting gap, also some feature at high energy (approx20 meV).

  2. Structural studies of type N superconductive compounds: R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} (R = Gd, Eu, Sm, Nd, Pr); influences of chemical treatments on physical properties; Etudes structurales des composes supraconducteurs de type N: R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} (R = Gd, Eu, Sm, Nd, Pr); influences des traitements chimiques sur les proprietes physiques

    Energy Technology Data Exchange (ETDEWEB)

    Vigoureux, P.

    1995-06-01

    Different chemical treatments of R{sub 2-x}Ce{sub x}CuO{sub 4{+-}{delta}} compounds monocrystals (gadolinium, europium, samarium, neodymium and praseodymium cuprates) modify their physical properties especially their superconductive properties. The presented chemical treatments are: the substitution of the trivalent rare earth element R by an other trivalent lanthanide, its substitution by tetravalent cerium, and heat treatment under low oxygen pressure. After these chemical treatments, structural modifications are observed by neutrons and X-rays diffraction, and allow to precise their actions: size effect of the rare earth element on the deformation of the CuO{sub 2} planes, links between deformation and superconductivity and magnetic properties. (A.B.). 394 refs/.

  3. Recent progress on compositional nanostripes of REBa2Cu3O7-δ (RE = Sm,Eu,Gd) superconductors

    International Nuclear Information System (INIS)

    We characterized ordered compositional fluctuation in high-quality SmBa2Cu3O7-δ, (Sm0.5Eu0.5)Ba2Cu3O7-δ, and (Sm0.33Eu0.33Gd0.33)Ba2Cu3O7-δ superconductors by atomic force microscopy, scanning tunnelling microscopy, and transmission electron microscopy. The presence of nanostripes along the crystalline c direction was confirmed in SmBa2Cu3O7-δ single crystals and in melt-processed (Sm0.5Eu0.5)Ba2Cu3O7-δ, (Sm0.33Eu0.33Gd0.33)Ba2Cu3O7-δ materials. Meanwhile, thickness fringes originating from the twin boundaries were also identified in some samples; these could be clearly separated from real nanostripes with sample tilting. Compositional nanostripes displayed spatial variation in both shape and wavelength over a large area of RE-Ba-Cu-O single domains. The origin of the nanostripe is discussed in the context of the competitive growth mechanism of RE1+xBa2-xCu3O7-δ solid solution

  4. Syngas production on a symmetrical solid oxide H2O/CO2 co-electrolysis cell with Sr2Fe1.5Mo0.5O6-Sm0.2Ce0.8O1.9 electrodes

    Science.gov (United States)

    Wang, Yao; Liu, Tong; Fang, Shumin; Chen, Fanglin

    2016-02-01

    High temperature H2O/CO2 co-electrolysis process is performed on the symmetrical Sr2Fe1.5Mo0.5O6(SFM)-Sm0.2Ce0.8O1.9(SDC)/La0.8Sr0.2Ga0.87Mg0.13O3 (LSGM)/SFM-SDC cells, which exhibit excellent electrochemical performance with the current density of -734 mAcm-2 at 1.3 V and the interfacial polarization resistance of 0.48 Ωcm2 at 850 °C. Enhanced co-electrolysis kinetics are obtained with increasing the operating temperature and applied cell voltage. Synthesis gas of H2 and CO is produced by H2O splitting and reverse water gas shift (RWGS) reaction on the SFM-SDC/LSGM/SFM-SDC co-electrolysis cells. Effects of temperature and electrolysis current on the produced gas fraction are predicted using the chemical equilibrium co-electrolysis model. High CO2 conversion rate and ideal H2 to CO ratio of approximately 2 can be achieved by adjusting appropriate inlet gas fraction, temperature and electrolysis current. The SFM-SDC/LSGM/SFM-SDC cell shows a relative stable cell voltage in the 103-h galvanostatic test.

  5. Microscopic mechanistic study on the multiferroic of R2CoMnO6/La2CoMnO6 (R = Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm) by chemical and hydrostatic pressures: a first-principles calculation.

    Science.gov (United States)

    Meng, Junling; Liu, Xiaojuan; Hao, Xianfeng; Zhang, Lifang; Yao, Fen; Meng, Jian; Zhang, Hongjie

    2016-09-14

    A specific class of multiferroic superlattices R2CoMnO6/La2CoMnO6 (R = Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm), which displayed observable electric polarizations and considerable magnetization, were investigated based on density functional theory. The multiferroic behavior was induced by both of the a(-)a(-)c(+) Glazer rotation patterns of BO6 (CoO6 and MnO6) octahedra and ferromagnetic coupling in the magnetic ordered superlattices. In addition, the ferroelectric and ferromagnetic properties of R2CoMnO6/La2CoMnO6 superlattices can be tuned by chemical pressure and hydrostatic pressure, with the former being more effective in tuning magnetoelectric properties than the latter. For chemical pressure, the incorporation of lanthanide ions promoted an increase of BO6 octahedral tilting, reflected by the sharp decrease of Co-O3-Mn bond angles in the R-layer along the c axis. By contrast, the hydrostatic pressure acts on all three directions of the superlattice so that the change in Co-O-Mn bond angles is relatively small, therefore the octahedral distortion is much smaller than that caused by chemical pressure. Consequently, the electric polarization and magnetization changed more slowly. Our first-principles simulations proposed a series of rational multiferroic superlattices with tunable ferromagnetism and ferroelectricity by chemical and hydrostatic pressures, with expectation to be applied as novel spintronic materials. PMID:27506617

  6. Materiales ferroeléctricos basados en BaTiO3 y Ba2(Nd,Sm)Ti2Nb3O15. Caracterización eléctrica por espectroscopia de impedancia

    OpenAIRE

    Prades Tena, Marta

    2011-01-01

    Esta tesis versa en la síntesis, mediante métodos de baja temperatura(sol-gel y solvotermal), la caracterización y el estudio de las propiedades eléctricas, mediante Espectroscopia de Impedancia, de dos tipos de materiales ferroeléctricos: el óxido mixto de titanio y bario, BaTiO3(BT), dopado con diferentes iones (con estructura perovsquita), y la familia de compuestos Ba2LnTi2Nb3O15 (Ln = ión lantánido), con estructura de bronce de tungsteno tetragonal (TTB). Los principales resultados en el...

  7. A cobalt-free SrFe 0.9Sb 0.1O 3- δ cathode material for proton-conducting solid oxide fuel cells with stable BaZr 0.1Ce 0.7Y 0.1Yb 0.1O 3- δ electrolyte

    Science.gov (United States)

    Ling, Yihan; Zhang, Xiaozhen; Wang, Songlin; Zhao, Ling; Lin, Bin; Liu, Xingqin

    A cobalt-free cubic perovskite oxide SrFe 0.9Sb 0.1O 3- δ (SFSb) is investigated as a novel cathode for proton-conducting solid oxide fuel cells (H-SOFCs). XRD results show that SFSb cathode is chemically compatible with the electrolyte BaZr 0.1Ce 0.7Y 0.1Yb 0.1O 3- δ (BZCYYb) for temperatures up to 1000 °C. Thin proton-conducting BZCYYb electrolyte and NiO-BaZr 0.1Ce 0.7Y 0.1Yb 0.1O 3- δ (NiO-BZCYYb) anode functional layer are prepared over porous anode substrates composed of NiO-BZCYYb by a one-step dry-pressing/co-firing process. Laboratory-sized quad-layer cells of NiO-BZCYYb/NiO-BZCYYb/BZCYYb/SFSb are operated from 550 to 700 °C with humidified hydrogen (∼3% H 2O) as fuel and the static air as oxidant. An open-circuit potential of 0.996 V, maximum power density of 428 mW cm -2, and a low electrode polarization resistance of 0.154 Ω cm 2 are achieved at 700 °C. The experimental results indicate that the cobalt-free SFSb is a promising candidate for cathode material for H-SOFCs.

  8. Properties of the (Sm sub 0 sub . sub 3 sub 3 Eu sub 0 sub . sub 3 sub 3 Gd sub 0 sub . sub 3 sub 3)Ba sub 2 Cu sub 3 O sub y superconductor prepared by different processes in air

    CERN Document Server

    Giovannelli, F; Monot-Laffez, I

    2003-01-01

    Bars and pellets of the (Sm sub 0 sub . sub 3 sub 3 Eu sub 0 sub . sub 3 sub 3 Gd sub 0 sub . sub 3 sub 3)Ba sub 2 Cu sub 3 O sub x superconductor were processed in air, using the floating zone method and the top-seeded melt-textured growth method, respectively. The samples were prepared using different experimental conditions, i.e. maximal processing temperature, translation rate or cooling rate. Their physical properties and their microstructure were studied. All the samples exhibit a satisfying superconducting transition whereas the critical current density greatly depends on the processing parameters. The sample prepared by the floating zone method at 1070 deg C with a translation rate of 2 mm h sup - sup 1 exhibits a very high J sub c value of 70000 A cm sup - sup 2 in the self-field and more than 30000 A cm sup - sup 2 at 1.7 T. The pellet processed at 1080 deg C with a cooling rate of 2 deg C h sup - sup 1 has a high J sub c reaching about 56000 A cm sup - sup 2 in the self-field and more than 32000 A ...

  9. Impedance spectroscopy studies on (Na0.5Bi0.5)0.94Ba0.06TiO3 + 0.3 wt% Sm2O3 + 0.25 wt% LiF lead-free piezoelectric ceramics

    Indian Academy of Sciences (India)

    N Zidi; A Chaouchi; S D’Astorg; M Rguiti; C Courtois

    2015-06-01

    The a.c. complex impedance spectroscopy technique was used to obtain the electrical parameters of (Na0.5Bi0.5)0.94Ba0.06TiO3 +0.3 wt% Sm2O3 +0.25 wt% LiF lead-free ceramics in a wide frequency range at different temperatures. These samples were prepared by a high-temperature solid-state reaction technique and their single phase formation was confirmed by the X-ray diffraction technique. Dielectric studies exhibit a diffuse phase transition characterized by a temperature and frequency dispersion of permittivity, and this relaxation has been modelled using the modified Curie–Weiss law. The variation of imaginary part (″) of impedance with frequency at various temperatures shows that the ″ values reach a maxima peak (″max) above 400° C. The appearance of single semicircle in the Nyquist plots (″ vs. ′) pattern at high temperatures suggests that the electrical process occurring in the material has a relaxation process possibly due to the contribution for bulk material only. The bulk resistance of the material decreases with rise in temperatures similar to that of a semiconductor, and the Nyquist plot showed the negative temperature coefficient of resistance (NTCR) character of these materials. The frequencies, thermal effect on a.c. conductivity and activation energy have been assessed.

  10. Synthesis by spark plasma sintering of a novel protonic/electronic conductor composite: BaCe0.2Zr0.7Y0.1O3−δ /Sr0.95Ti0.9Nb0.1O3−δ (BCZY27/STN95)

    DEFF Research Database (Denmark)

    Fish, Jason; Ricote, Sandrine; Lenrick, Filip;

    2013-01-01

    A novel two-phase ceramic composite (cercer) material consisting of a solid solution of barium cerate and -zirconate doped with yttrium (BaCe0.2Zr0.7Y0.1O3−δ : BCZY27), together with niobium-doped strontium titanate (Sr0.95Ti0.9Nb0.1O3−δ : STN95), has been synthesized by solid-state reaction...

  11. Draft Genome Sequences of Stenotrophomonas maltophilia Strains Sm32COP, Sm41DVV, Sm46PAILV, SmF3, SmF22, SmSOFb1, and SmCVFa1, Isolated from Different Manures in France.

    Science.gov (United States)

    Bodilis, Josselin; Youenou, Benjamin; Briolay, Jérome; Brothier, Elisabeth; Favre-Bonté, Sabine; Nazaret, Sylvie

    2016-01-01

    Stenotrophomonas maltophilia is a major opportunistic human pathogen responsible for nosocomial infections. Here, we report the draft genome sequences of Sm32COP, Sm41DVV, Sm46PAILV, SmF3, SmF22, SmSOFb1, and SmCVFa1, isolated from different manures in France, which provide insights into the genetic determinism of intrinsic or acquired antibiotic resistance in this species. PMID:27540065

  12. Ternary rare-earth titanium antimonides: Phase equilibria in the RE-Ti-Sb (RE=La, Er) systems and crystal structures of RE2Ti7Sb12 (RE=La, Ce, Pr, Nd) and RETi3(SnxSb1-x)4 (RE=Nd, Sm)

    International Nuclear Information System (INIS)

    Investigations on phase relationships and crystal structures have been conducted on several ternary rare-earth titanium antimonide systems. The isothermal cross-sections of the ternary RE-Ti-Sb systems containing a representative early (RE=La) and late rare-earth element (RE=Er) have been constructed at 800 deg. C. In the La-Ti-Sb system, the previously known compound La3TiSb5 was confirmed and the new compound La2Ti7Sb12 (own type, Cmmm, Z=2, a=10.5446(10) A, b=20.768(2) A, and c=4.4344(4) A) was discovered. In the Er-Ti-Sb system, no ternary compounds were found. The structure of La2Ti7Sb12 consists of a complex arrangement of TiSb6 octahedra and disordered fragments of homoatomic Sb assemblies, generating a three-dimensional framework in which La atoms reside. Other early rare-earth elements (RE=Ce, Pr, Nd) can be substituted in this structure type. Attempts to prepare crystals in these systems through use of a tin flux resulted in the discovery of a new Sn-containing pseudoternary phase RETi3(SnxSb1-x)4 for RE=Nd, Sm (own type, Fmmm, Z=8; a=5.7806(4) A, b=10.0846(7) A, and c=24.2260(16) A for NdTi3(Sn0.1Sb0.9)4; a=5.7590(4) A, b=10.0686(6) A, and c=24.1167(14) A for SmTi3(Sn0.1Sb0.9)4). Its structure consists of double-layer slabs of Ti-centred octahedra stacked alternately with nets of the RE atoms; the Ti atoms are arranged in kagome nets. - Graphical abstract: La2Ti7Sb12 contains sectioned layers consisting of Ti-centred octahedra linked by corner- and face-sharing

  13. Thermophysical properties of Sm2(Zr1-xCex)2O7 ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hongsong; SUN Kun; XU Qiang; WANG Fuchi; LIU Ling; WEI Yuan; CHEN Xiaoge

    2009-01-01

    Sm2(Zr1-xCex)2O7 (x = 0.1, 0.2, and 0.3) ceramics were prepared by solid reaction method at 1600~C for 10 h using Sm2O3, ZrO2, and CeO2as starting reactants. The phase compositions, microstructures, thermal expansion coefficients, and partial thermal conductivities of these materials were investigated. X-ray diffraction (XRD) results reveal that Sm2(Zr0.gCe0.t~zO7 with pyrochiore structure and Sm2(Zr1-xCex)2O7 (x = 0.2 and 0.3) with fluorite structure were synthesized, and scanning electrical microscopy (SEM) images show that the microstructures of these products are very dense. The linear thermal expansion coefficients increase with increasing temperature in the temperature range from ambient to 1200℃, and the thermal expansion coefficients increase with increasing content of doped CeO2. The thermal conductivities of Sm2(Zr0.8Ce0.2)2O7 and Sm2(Zr0.7Ce0.3)2O7 decrease gradually with an increase in temperature. These results show that the synthesized ceramic materials can be explored as novel prospective candidate materials for use in new thermal barrier coating systems in the future.

  14. Performance of Composite Cathode Sr0.95Ti0.05Co0.95O3-δ-Sm0.2Ce0.8O1.9 Used in Intermediate Temperature SOFCs%新型复合阴极 Sr0.95Ti0.05Co0.95O3-δ-Sm0.2Ce0.8O1.9在中低温固体氧化物燃料电池中的性能

    Institute of Scientific and Technical Information of China (English)

    余良浩; 王晓晴; 林彬; 田冬; 卢肖永; 顾庆文; 陈永红

    2015-01-01

    采用柠檬酸自蔓延燃烧法合成了 Sr0.95Ti0.05Co0.95O3−δ(STC)阴极粉体和 Sm0.2Ce0.8O1.9(SDC)电解质粉体,将 STC 与SDC 粉体按质量比7:3混合得到复合阴极。通过 X 射线衍射(XRD)、直流四端子法和热膨胀仪表征了样品的化学相容性、电导率和热膨胀系数。XRD 表明,STC 在900℃能够得到立方纯钙钛矿结构,复合阴极 STC−SDC 在工作温度区间内具有很好的化学相容性;在650℃空气气氛下 STC−SDC 与 SDC 之间的界面极化阻抗仅为0.05Ω·cm2。制备了阳极支持型(NiO-SDC│SDC│STC−SDC)单电池,在450~650℃范围内以湿润的 H2(3%水蒸汽)为燃料气,空气为氧化剂测试了单电池的性能。结果表明:阳极支撑的单电池共烧1350℃可以得到致密的电解质层和多孔的电极,而且650℃时单电池开路电压0.82 V,最大输出功率为721 mW/cm2。结果预示,在以 SDC 为电解质的中低温固体氧化物燃料电池(IT-SOFC)中,STC-SDC 是一个很有前途的复合阴极材料。%A cathode powder of Sr0.95Ti0.05Co0.95O3−δ(STC) and an electrolyte powder of Sm0.2Ce0.8O1.9 (SDC) were synthesized by a citric acid-nitrates self-propagating combustion method. The composite-cathode was obtained by mixing the STC and SDC powders in a mass ratio of 7:3. The chemical compatibility, electrical conductivity and thermal expansion coefficient of the composite cathode were characterized by X-ray diffraction(XRD), direct current four-terminal method and thermal dilatometer, respectively. The XRD results show that a pure cubic STC perovskite phase can be obtained at 900 and℃ no second phase is formed in the composite cathode at the operating temperature. The polarization resistance of the electrode is only 0.05 Ω·cm2 at 650 ℃. The anode-supported solid oxide fuel cells of NiO-SDC│SDC│STC−SDC were fabricated. The electrochemical performances were examined at 450−650 ℃ with humidified hydrogen (about 3

  15. Tuning the Thickness of Ba-Containing "Functional" Layer toward High-Performance Ceria-Based Solid Oxide Fuel Cells.

    Science.gov (United States)

    Gong, Zheng; Sun, Wenping; Shan, Duo; Wu, Yusen; Liu, Wei

    2016-05-01

    Developing highly efficient ceria-based solid oxide fuel cells with high power density is still a big concern for commercial applications. In this work, a novel structured Ce0.8Sm0.2O2-δ (SDC)-based fuel cell with a bilayered anode consisting of Ni-SDC and Ni-BaZr0.1Ce0.7Y0.2O3-δ (Ni-BZCY) was designed. In addition to the catalysis function, the Ni-BZCY anode "functional" layer also provides Ba source for generating an electron-blocking layer in situ at the anode/electrolyte interface during sintering. The Ni-BZCY thickness significantly influences the quality of the electron-blocking layer and electrochemical performances of the cell. The cell with a 50 μm thick Ni-BZCY layer exhibits the best performance in terms of open circuit voltage (OCV) and peak power density (1068 mW cm(-2) at 650 °C). The results demonstrate that this cell with an optimal structure has a distinct advantage of delivering high power performance with a high efficiency at reduced temperatures.

  16. Rare earth metal doped CeO2-based catalytic materials for diesel soot oxidation at lower temperatures

    Institute of Scientific and Technical Information of China (English)

    A Rangaswamy; Putla Sudarsanam; Benjaram M Reddy

    2015-01-01

    In this work, the influence of trivalent rare-earth dopants (Sm and La) on the structure-activity properties of CeO2 was thor-oughly studied for diesel soot oxidation. For this, an optimized 40%of Sm and La was incorporated into the CeO2 using a facile co-precipitation method from ultra-high dilute aqueous solutions. A systematic physicochemical characterization was carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM), Brumauer-Emmett-teller method (BET) surface area, X-ray pho-toelectron spectroscopy (XPS), Raman, and H2-temperature programmed reduction (TPR) techniques. The soot oxidation efficiency of the catalysts was investigated using a thermogravimetric method. The XRD results suggested the formation of nanocrystalline sin-gle phase CeO2-Sm2O3 and CeO2-La2O3 solid solutions. The Sm-and La-doped CeO2 materials exhibited smaller crystallite size and higher BET surface area compared with the pure CeO2. Owing to the difference in the oxidation states of the dopants (Sm3+and La3+) and the Ce4+, a number of oxygen vacancies were generated in CeO2-Sm2O3 and CeO2-La2O3 samples. The H2-TPR studies evidenced the improved reducible nature of the CeO2-Sm2O3 and CeO2-La2O3 samples compared with the CeO2. It was found that the addition of Sm and La to the CeO2 outstandingly enhanced its catalytic efficiency for the oxidation of diesel soot. The observed 50%soot con-version temperatures for the CeO2-Sm2O3, CeO2-La2O3 and CeO2 were~790, 843 and 864 K (loose contact), respectively, and similar activity order was also found under the tight contact condition. The high soot oxidation efficacy of the CeO2-Sm2O3 sample was at-tributed to numerous catalytically favourable properties, like smaller crystallite size, larger surface area, abundant oxygen vacancies, and superior reducible nature.

  17. Microstructure and performance of La0.58Sr0.4Co0.2Fe0.8O3−δ cathodes deposited on BaCe0.2Zr0.7Y0.1O3−δ by infiltration and spray pyrolysis

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Bonanos, Nikolaos; Rørvik, Per Martin;

    2012-01-01

    La0.58Sr0.4Co0.2Fe0.8O3−δ (LSCF) cathodes have been deposited on proton-conducting BaCe0.2Zr0.7Y0.1O3−δ (BCZY27) electrolyte and studied in symmetric cells to investigate the cathode microstructure and electrochemical performance. Three different types of cathodes have been prepared: two prepared...... and 600°C in air, with varying p(H2O), reveals that the charge transfer contribution is the lowest for the backbone-infiltrated cathode while the oxygen dissociation/adsorption contribution is the lowest for the spray-pyrolyzed cathode. The area specific resistances increase with the water vapor pressure...

  18. Semi-empirical calculations of radiative rates for parity-forbidden transitions within the 4f2 configuration of Ba-like ions La+, Ce2+, Pr3+ and Nd4+ and 4f12 configuration of Dy-like Yb4+

    International Nuclear Information System (INIS)

    The experimental free ion 4f12 energy levels for Yb4+ have been fitted to the standard f-shell free ion Hamiltonian, which includes the major electrostatic and spin–orbit terms as well as various minor contributions like two-body, spin–spin, spin–other-orbit and electrostatically correlated spin–orbit interactions. Then, the fitted values of free ion parameters and the corresponding eigenstates are used to calculate the oscillator strengths for all absorption transitions and the spontaneous emission rates for all magnetic dipole and electric quadrupole transitions, originating from levels of the 4f2 configuration in Ba-like ions La+, Ce2+, Pr3+ and Nd4+, and the conjugate electron configuration 4f12 in Dy-like Yb4+ ions. Our calculated results are also compared with some findings available in the literature. (paper)

  19. The WWR-SM-20 research reactor

    International Nuclear Information System (INIS)

    In this paper the design features and experimental capabilities of the WWR-SM-20 research reactor are described. The reactor uses fuel assemblies consisting of six coaxial fuel tubes with a square cross-section. IRT-3M fuel assemblies can be used with both 90% enriched and 36% enriched uranium. The main characteristics of the IRT-3M fuel assemblies are given, as are the technical and physical parameters of the WWR-SM-20 reactor. The core can hold up to ten ampoule-type channels with a diameter of up to 68 mm. For irradiation purposes, up to 22 26-mm-diameter channels in the fuel assemblies, and up to 48 42-mm-diameter channels in the beryllium blocks of the reflector can be used. In the graphite blanket between the horizontal channels, channels with a diameter of up to 130 mm can be used. The thermal neutron flux density has a maximum value of 1.5 X 1018 m-2 · s-1 in the core and 2.3 X 1018 m-2 · s-1 in the reflector, and the fast neutron flux density (cE > 0.821 MeV) a maximum of 1.9 X 1018 m-2 · s-1. A number of design features have been incorporated in the WWR-SM-20 reactor to make it effectively safe

  20. Nonisothermal Kinetice of Dehydration Process of [Sm(m-CIBA)3phen]2·2H2O and[Sm(p-CIBA)3phen]2·2H2O

    Institute of Scientific and Technical Information of China (English)

    REN Ning; WANG Xie; ZHANG Jie; ZHANG Jian-jun; XU Su-ling; ZHANG Hai-yan

    2008-01-01

    Compounds[Sm(m-CIBA)3phen]2·2H2O and[Sm(p-ClBA)3phen]2·2H2O(m-ClBA=m-chlorobenzoate,PClBA=p-chlorobenzoate,phen=1,10-phenanthroline)were prepared.The dehydration processes and kinetics of these compounds were studied from the analysis of the DSC curves using a method of processing the data of thermal analysis kinetics.The Arrhenius equation for the dehydration process can be expressed as lnk=38.65-243.90x103|RT for and△S≠ of dehydration reaction for the title compounds are determined,respectively.

  1. Luminescence properties of the Sm-doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kindrat, I.I. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Padlyak, B.V., E-mail: B.Padlyak@if.uz.zgora.pl [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Vlokh Institute of Physical Optics, 23 Dragomanov Street, 79-005 Lviv (Ukraine); Drzewiecki, A. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland)

    2015-10-15

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, CaB{sub 4}O{sub 7}, and LiCaBO{sub 3} compositions were investigated and analysed. The Li{sub 2}B{sub 4}O{sub 7}:Sm, LiKB{sub 4}O{sub 7}:Sm, CaB{sub 4}O{sub 7}:Sm, and LiCaBO{sub 3}:Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm{sup 3+} (4f{sup 5}, {sup 6}H{sub 5/2}) ions, exclusively. All observed 4f – 4f transitions of the Sm{sup 3+} centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm{sup 3+} ions peaked about 598 nm ({sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm{sup 3+} luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm{sup 3+} centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce{sup 3+} non-controlled impurity and intrinsic luminescence centres to the Sm{sup 3+} centres has been observed. Peculiarities of the Sm{sup 3+} local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, Ca

  2. SM18 Visits and Access

    CERN Multimedia

    2012-01-01

      VISITS The rules and conditions to be followed for visits in the SM18 Hall are laid out in the EDMS 1205328 document. No visit is allowed without prior reservation.   ACCESS Special access right is needed ONLY from 7 p.m. to 7 a.m. and during week-ends. From 1 December, the current SM18 access database will be closed and a new one “SM18-OWH outside normal hours” started from scratch. Requests, via EDH SM18-OWH, will have to be duly justified.   For further information, please contact Evelyne Delucinge.

  3. Highly Enhanced Concentration and Stability of Reactive Ce^3+ on Doped CeO_2 Surface Revealed In Operando

    OpenAIRE

    Chueh, William C.; McDaniel, Anthony H.; Grass, Michael E.; Hao, Yong; Jabeen, Naila; Liu, Zhi; Haile, Sossina M.; McCarty, Kevin F.; Bluhm, Hendrik; El Gabaly, Farid

    2012-01-01

    Trivalent cerium ions in CeO_2 are the key active species in a wide range of catalytic and electro-catalytic reactions. We employed ambient pressure X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy to quantify simultaneously the concentration of the reactive Ce^3+ species on the surface and in the bulk of Sm-doped CeO_2(100) in hundreds of millitorr of H2–H2O gas mixtures. Under relatively oxidizing conditions, when the bulk cerium is almost entirely in the 4+ oxida...

  4. Electrochemical performance and carbon deposition resistance of M-BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (M = Pd, Cu, Ni or NiCu) anodes for solid oxide fuel cells

    Science.gov (United States)

    Li, Meng; Hua, Bin; Pu, Jian; Chi, Bo; Jian, Li

    2015-01-01

    Pd-, Cu-, Ni- and NiCu-BaZr0.1Ce0.7Y0.1Yb0.1O3-δ anodes, designated as M-BZCYYb, were prepared by impregnating M-containing solution into BZCYYb scaffold, and investigated in the aspects of electrocatalytic activity for the reactions of H2 and CH4 oxidation and the resistance to carbon deposition. Impregnation of Pd, Ni or NiCu significantly reduced both the ohmic (RΩ) and polarization (RP) losses of BZCYYb anode exposed to H2 or CH4, while Cu impregnation decreased only RΩ in H2 and the both in CH4. Pd-, Ni- and NiCu-BZCYYb anodes were resistant to carbon deposition in wet (3 mol. % H2O) CH4 at 750°C. Deposited carbon fibers were observed in Pd- and Ni-BZCYYb anodes exposed to dry CH4 at 750°C for 12 h, and not observed in NiCu-BZCYYb exposed to dry CH4 at 750°C for 24 h. The performance of a full cell with NiCu-BZCYYb anode, YSZ electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-δ-Gd doped CeO2 (LSCF-GDC) cathode was stable at 750°C in wet CH4 for 130 h, indicating that NiCu-BZCYYb is a promising anode for direct CH4 solid oxide fuel cells (SOFCs).

  5. Phonon modes in Gd1-xCexBa2Cu3O7-δ

    Directory of Open Access Journals (Sweden)

    SH Mozaffari

    2009-08-01

    Full Text Available  XRD and Raman analyses were performed to probe the phase formation and the variation of the normal phonon frequencies of the high temperature superconductor GdBa2Cu3O7-δ upon Ce doping. It was found that in addition to the orthorhombic 123 phase, some nonsuperconducting peaks, which are mainly due to the BaCeO3 secondary phase, are also formed that suppress the superconducting transition temperature. Besides, analysis of the Raman peaks shows that substitutions of Ce for Gd in GdBa2Cu3O7-δ are restricted to low concentrations in favor of impurity island formation .

  6. Separation of Red(Y_2O_3:Eu~(3+)),Blue(Sr,Ca,Ba)_(10)(PO_4)_6Cl_2:Eu~(2+)and Green(LaPO_4:Tb~(3+),Ce~(3+))Rare Earth Phosphors by Liquid/Liquid Extraction

    Institute of Scientific and Technical Information of China (English)

    MEI Guangjun; RAO Peng; MITSUAKI Matsuda; TOYOHISA Fujita

    2009-01-01

    A novel process for separation of red(Y_2O_3:Eu~(3+)),blue(Sr,Ca,Ba)_(10)(PO_4)_6Cl_2:Eu~(2+) and green(LaPO_4:Tb~(3+),Ce~(3+) )fine tricolor phosphor powders was established.First,the green phosphor was extracted and separated from three phosphor mixtures in heptane/DMF(N,N-Dimethylformamide)system using stearylamine or laurylamine(DDA)as the cationic surfactant.Then,after being treated with 99.5%ethanol,the blue and red phosphors could be separated in Heptane/DMF system in presence of 1-octanesulfonic acid sodium salt as the anionic surfactant.Satisfactory separation results have been achieved through two steps extractions with their artificial mixtures.The grades and recovery of separated products reached respectively as follows:red product was 95.3%and 90.9%,blue product was 90.0%and 95.2%,and green product was 92.2%and 91.8%.

  7. Preparation and Oxygen Permeability of BaCo0.7Fe0.2Nb0.1O3-δ Membrane Modified by Ce0.8Y0.2O2-δ Porous Layer on the Air Side

    Directory of Open Access Journals (Sweden)

    Yuan Qiang

    2013-01-01

    Full Text Available BaCo0.7Fe0.2Nb0.1O3−δ (BCFN dense ceramic membrane with submicron-Ce0.8Y0.2O2−δ (YDC porous layer was investigated by the partial oxidation of coke oven gas (COG in hydrogen production. XRD analysis showed this composite had good stability and no chemical reaction at high temperature. SEM and TEM characterization further showed BCFN membrane was uniformly modified by YDC porous layer (about 5~6 μm thickness formed by the accumulation of relative nanoparticles. At the respective COG flux and air flux of 108 mL/min and 173 mL/min, the oxygen permeation flux of BCFN modified by submicron-YDC porous layer reached 16.62 mL·min−1·cm−2, which was about 23.5% higher than that of pure BCFN membrane. Therefore, submicron-YDC porous layer obviously improved the oxygen permeation flux of BCFN membrane and its stability at 875°C.

  8. COMPARISION OF THE COLOR PROPERTIES OF COMPOUNDS Ln2Ce2O7 AND Ln2CeZrO7

    OpenAIRE

    B. Hablovicova; P. Sulcova

    2015-01-01

    Pyrochlore type pigments Ln2Ce2O7 and Ln2CeZrO7 (Ln = Nd, Sm, Gd, Dy, Er, Yb and Y) prepared by solid-state reaction were investigated. Effect of rare earths and zirconium ions and calcination temperature (1400, 1500 and 1600oC for Ln2Ce2O7 and 1400, 1450 and 1500 C for Ln2CeZrO7) on their color properties in organic matrix and ceramic glazes, particle size distribution and phase composition were evaluated. The most interesting shades achieve compounds with the highest calcination temperature...

  9. Fabrication of large single-domain Sm123 superconductors by OCMG method

    International Nuclear Information System (INIS)

    Melt processing of Sm-Ba-Cu-O bulk superconductors was studied to find the optimum conditions for fabricating a large single-domain superconductor. First, the holding time at the maximum temperature for the partial melting is important for the fabrication of a uniform bulk, especially for a large diameter. When the holding time at the maximum temperature during partial melting was not enough, two separated regions were observed, which can be diminished by sufficient holding time. Next we studied the optimum conditions for grain growth, varying the temperature gr[ient and cooling rate. The processing condition with which we have succeeded in growing a single-domain SmBa2Cu3Oy (Sm123 hereafter) with dimensions of 35 φ x 15 mm2 is a temperature gr[ient of 7.5 C cm-1 with a slow cooling rate of 0.33 C h-1. (orig.)

  10. Synthesis and characterization of BaAl2O4:Eu2+ co-doped with different rare earth ions

    International Nuclear Information System (INIS)

    Combustion method was used in this study to prepare BaAl2O4:Eu2+ phosphors co-doped with different trivalent rare-earths (Re3+=Dy3+, Nd3+, Gd3+, Sm3+, Ce3+, Er3+, Pr3+ and Tb3+) ions at an initiating temperature of 600 °C. The phosphors were annealed at 1000 °C for 3 h. As confirmed from the X-ray diffraction (XRD) data, both as prepared and post annealed samples crystallized in the well known hexagonal structure of BaAl2O4. All samples exhibited bluish-green emission associated with the 4f65d1→4f7 transitions of Eu2+ at ∼500 nm. Although the highest intensity was observed from Er3+ co-doping, the longest afterglow (due to trapping and detrapping of charge carriers) was observed from Nd3+ followed by Dy3+ co-doping. The traps responsible for the long afterglow were studied using thermoluminescence (TL) spectroscopy.

  11. Application of Sm0/Auxiliary and Sm0/MCln System in Organic Synthesis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-Min; LIU Yun-Kuia

    2001-01-01

    @@Though samarium metal itself has strong reducingpower, in most cases, certain additives are still needed when it is used as a reductant because the surface of samarium metal is inactive.Thus Sm0/auxiliary systems are proposed.The explored systems include: Sm0/I2,Sm0/TMSCl, Sm0/THF-NH4Cl (aq.), Sm0/Cp2TiCl2,Sm(Hg), Sm0/cat.KI etc.

  12. SM*A*S*H

    CERN Document Server

    Ringwald, Andreas

    2016-01-01

    We present a minimal model for particle physics and cosmology. The Standard Model (SM) particle content is extended by three right-handed SM-singlet neutrinos N_i and a vector-like quark Q, all of them being charged under a global lepton number and Peccei-Quinn (PQ) U(1) symmetry which is spontaneously broken by the vacuum expectation value v_sigma around 10^{11} GeV of a SM-singlet complex scalar field sigma. Five fundamental problems -- neutrino oscillations, baryogenesis, dark matter, inflation, strong CP problem -- are solved at one stroke in this model, dubbed "SM*A*S*H" (Standard Model*Axion*Seesaw*Higgs portal inflation). It can be probed decisively by upcoming cosmic microwave background and axion dark matter experiments.

  13. Effect of Sintering Temperature on Microstructure, Chemical Stability and Electrical Properties of Transition Metal or Yb-Doped BaZr0.1Ce0.7Y0.1M0.1O3-δ (M = Fe, Ni, Co and Yb

    Directory of Open Access Journals (Sweden)

    Behzad eMirfakhraei

    2014-03-01

    Full Text Available Perovskite-type BaZr0.1Ce0.7Y0.1M0.1O3-δ (M = Fe, Ni, Co and Yb (BZCY-M oxides were synthesized using the conventional solid-state reaction method at 1350-1550 oC in air in order to investigate the effect of dopants on sintering, crystal structure, chemical stability under CO2 and H2S, and electrical transport properties. The formation of the single-phase perovskite-type structure with an orthorhombic space group Imam was confirmed by Rietveld refinement using powder X-ray diffraction (PXRD for the Fe, Co, Ni and Yb-doped samples. The BZCY-Co and BZCY-Ni oxides show a total electrical conductivity of 0.01 and 8 × 10-3 Scm-1 at 600 oC in wet H2 with an activation energy of 0.36 and 0.41 eV, respectively. Scanning electron microscopy (SEM and energy-dispersive X-ray analysis (EDX revealed Ba and Co rich secondary phase at the grain-boundaries, which may explain the enhancement in the total conductivity of the BZCY-Co. However, ex-solution of Ni at higher sintering temperatures, especially at 1550 oC, decreases the total conductivity of the BZCY-Ni material. The Co and Ni dopants act as a sintering aid and form dense pellets at a lower sintering temperature of 1250 oC. The Fe, Co and Ni-doped BZCY-M samples synthesized at 1350 oC show stability in 30 ppm H2S/H2 at 800 oC, and increasing the firing temperature to 1550 oC, enhanced the chemical stability in CO2 / N2 (1: 2 at 25-900 oC. The BZCY-Co and Ni compounds with high conductivity in wet H2 could be considered as possible anodes for intermediate temperature solid oxide fuel cells (IT-SOFCs.

  14. Why the Four SM Families

    CERN Document Server

    Sultansoy, S F

    2001-01-01

    The flavor democracy favors the existence of the nearly degenerate fourth SM family, whereas the fifth SM family is disfavored both by the mass phenomenology and precision tests of the Standard Model. The multi-hundreds GeV fourth family quarks will be copiously produced at the LHC. However, the first indication of the fourth family may come from the Higgs search at the upgraded Tevatron.

  15. Stability, characterization and functionality of proton conducting NiO–BaCe{sub 0.85−x}Nb{sub x}Y{sub 0.15}O{sub 3−δ} cermet anodes for IT-SOFC application

    Energy Technology Data Exchange (ETDEWEB)

    Žunić, Milan, E-mail: milan@iq.unesp.br [Instituto de Quimica, UNESP-LIEC, CMDMC, Rua Prof. Francisco Degni, 55, CEP 14800-900, Araraquara, SP (Brazil); Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11000 Belgrade (Serbia); Branković, Goran [Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11000 Belgrade (Serbia); Basoli, Francesco [Department of Chemical Science and Technologies, University of Rome Tor Vergata, Via Ricerca Scientifica 1, 00133 Rome (Italy); Cilense, Mario; Longo, Elson; Varela, José Arana [Instituto de Quimica, UNESP-LIEC, CMDMC, Rua Prof. Francisco Degni, 55, CEP 14800-900, Araraquara, SP (Brazil)

    2014-10-01

    Highlights: • The influence niobium concentration on properties of anode substrates was investigated. • The cermet anode powders were obtained without any undesirable phases. • Porous anode substrates showed chemical stability in the CO{sub 2} atmosphere. • Conductivity values of reduced anode samples were σ{sup *} > 50 S cm{sup −1}. • Fuel cell tests demonstrated functionality of anode substrates. - Abstract: There are many of properties of anodes based on proton conductors, like microstructure, conductivity and chemical stability, which should be optimized. In this work we were dealing with the influence of niobium on the chemical stability, microstructural and electrical characteristics of proton conducting NiO–BaCe{sub 0.85−x}Nb{sub x}Y{sub 0.15}O{sub 3−δ} (NiO–BCNYx) anodes. Four anode substrates NiO–BCNYx of different Nb concentration were prepared using the method of evaporation and decomposition of solutions and suspensions (EDSS). Sintered anode substrates were reduced and their microstructural and electrical properties were examined before and after reduction as a function of the amount of niobium. Chemical stability tests showed strong influence of Nb amount on the chemical stability of anodes in the CO{sub 2}. Microstructural properties of the anode pellets before and after testing in CO{sub 2} were investigated using X-ray diffraction analysis. Electrical properties of anode samples were examined by impedance spectroscopy measurements and the conductivity values of reduced anodes were more than 50 S cm{sup −1} at 600 °C confirming percolation through Ni particles. Fuel cells were fabricated with aim to examine the functionality of anodes. During the fuel cell test the cell with Ni–BCNY10 anode achieved the highest performance, demonstrating a peak power density of 164 mW cm{sup −2} at 650 °C, which confirmed the functionality of Ni–BCNY anodes.

  16. A cobalt-free SrFe{sub 0.9}Sb{sub 0.1}O{sub 3-{delta}} cathode material for proton-conducting solid oxide fuel cells with stable BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}Yb{sub 0.1}O{sub 3-{delta}} electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Yihan; Zhao, Ling; Lin, Bin; Liu, Xingqin [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Zhang, Xiaozhen [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Key Laboratory of Jiangxi Universities for Inorganic Membranes, School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Wang, Songlin [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Department of Mechanical Engineering, Tongling University (TLU), Tongling, Anhui 244000 (China)

    2010-10-15

    A cobalt-free cubic perovskite oxide SrFe{sub 0.9}Sb{sub 0.1}O{sub 3-{delta}} (SFSb) is investigated as a novel cathode for proton-conducting solid oxide fuel cells (H-SOFCs). XRD results show that SFSb cathode is chemically compatible with the electrolyte BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}Yb{sub 0.1}O{sub 3-{delta}} (BZCYYb) for temperatures up to 1000 C. Thin proton-conducting BZCYYb electrolyte and NiO-BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}Yb{sub 0.1}O{sub 3-{delta}} (NiO-BZCYYb) anode functional layer are prepared over porous anode substrates composed of NiO-BZCYYb by a one-step dry-pressing/co-firing process. Laboratory-sized quad-layer cells of NiO-BZCYYb/NiO-BZCYYb/BZCYYb/SFSb are operated from 550 to 700 C with humidified hydrogen ({proportional_to}3% H{sub 2}O) as fuel and the static air as oxidant. An open-circuit potential of 0.996 V, maximum power density of 428 mW cm{sup -2}, and a low electrode polarization resistance of 0.154 {omega} cm{sup 2} are achieved at 700 C. The experimental results indicate that the cobalt-free SFSb is a promising candidate for cathode material for H-SOFCs. (author)

  17. Optical properties of Ce3+ doped fluorophosphates scintillation glasses

    Science.gov (United States)

    Yao, Yongxin; Liu, Liwan; Zhang, Yu; Chen, Danping; Fang, Yongzheng; Zhao, Guoying

    2016-01-01

    Fluorophosphates (P2O5-BaO-BaF2-Al2O3-Gd2O3-Ce2O3) glasses with different Gd2O3 and BaF2 concentrations have been prepared by a melt quenching method. The effect of Gd2O3 and BaF2 on the glass performance including the density, absorption as well as luminescence properties under both ultraviolet (UV) and X-ray excitation was studied systematically. Energy transfer from Gd3+ to Ce3+ plays an important role in the scintillation mechanism of these glasses and the optimum concentration of Gd2O3 is found to be approximately 3 mol%. The highest integrated light emission intensity of these glass samples excited by X-ray is 25% of BGO and the decay time constants are in the range of 25-35 ns, much shorter than the 300 ns decay time of BGO. Meanwhile, replacing lighter compound BaO with the BaF2 can increase the density of the glasses and also improve the light yield.

  18. Phase equilibria in Sm-Ga-S ternary system according to SmGa2-GaS, SmGa2-SmS, Sm3S4-Ga2S3, SmS-GaS, Sm-GaS cross sections

    International Nuclear Information System (INIS)

    Phase equilibria in ternary system Sm-Ga-S over cross sections SmGa2-GaS, SmGa2-SmS, SmS-GaS, Sm3S4-Ga2S3, Sm-GaS have been studied for the first time using the methods of physicochemical analysis, their T-x projections were plotted. The cross sections SmGa2-GaS, SmGa2-SmS, Sm3S4-Ga2S3 and SmS-GaS are quasibinary, while Sm-GaS is nonquasibinary one. Formation of two ternary compounds of the composition Sm4GaS5 and Sm5Ga2S5 was ascertained by peritectic reactions

  19. Surface morphology and in-plane-epitaxy of SmBa2Cu3O7 films on SrTiO3 (001) substrates studied by STM and grazing incidence x-ray diffraction

    DEFF Research Database (Denmark)

    Jiang, Q.D.; Smilgies, D.M.; Feidenhans'l, R.;

    1996-01-01

    as thick as 500 Angstrom grow pseudomorphically on SrTiO3 (001) surfaces, in comparison with a maximum of 130 Angstrom for YBCO. This is probably due to a better lattice match of SmBCO (epsilon(alpha) = 1.2%, epsilon(b)=-0.5%) compared to YBCO (epsilon(alpha)=2.0%, epsilon(b)=0.5%) with the SrTiO3...

  20. Solvothermal fabrication and luminescent properties of Eu2+/Ce3+ doped barium lithium fluoride

    Institute of Scientific and Technical Information of China (English)

    ZHU Guoxian; YANG Qu; SHI Xiaobo; ZHENG Wenzhi; LIU Yingliang

    2012-01-01

    Phosphors of BaLiF3 doped with Eu or/and Ce were solvothermally prepared at 200 ℃ for 5 d and characterized by means of X-ray powder diffraction (XRD) and environment scanning electron microscopy (ESEM).The excitation and emission spectra of the rare earth ions doped BaLiF3 were measured by fluorescence spectroscopy and the effects of Ce3+ions on the luminescence of Eu2+ions were investigated,In the co-doped Eu2+ and Ce3+ system,the emission intensity ofEu2+ ion gradually increased with the Ce3+ concentration increasing,and the enhancement ofEu2+ fluorescence was due to efficient energy transfer from Ce3+ to Eu2+ in the host.

  1. Improving CE with PDM

    NARCIS (Netherlands)

    Wognum, P.M. (Nel); Bondarouk, T.V. (Tanya); Weber, F.; Pawar, K.S.; Thoben, K.D.

    2003-01-01

    The concept of Concurrent Engineering (CE) centers around the management of information so that the right information will be at the right place at the right time and in the right format. Product Data Management (PDM) aims to support a CE way of working in product development processes. In specific

  2. Effect of BaO on Catalytic Activity of Pt-Rh TWC

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of BaO doping on the three-way catalytic activity of Pt-Rh catalyst and on water-gas shift were investigated. The results show that the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides of the fresh catalysts slightly differ from those of the aged catalysts, and the catalysts containing CeO2-ZrO2-BaO have lower lightoff temperature and better catalytic activity than these containing BaO and CeO2-ZrO2 after hydrothermal aging for 5 h at 1000 C. The catalysts were characterized by means of the temperature-programmed reduction (TPR) in hydrogen and the temperature-programmed desorption (TPD) in oxygen. It is confirmed that the suggested route of CeO2-ZrO2-BaO by coprecipitation can improve the catalytic activity of catalysts.

  3. Synthesis and characterization of BaAl{sub 2}O{sub 4}:Eu{sup 2+} co-doped with different rare earth ions

    Energy Technology Data Exchange (ETDEWEB)

    Lephoto, M.A. [Department of Physics, University of the Free State, Private bag X 13, Phuthaditjaba 9866, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Ntwaeaborwa, O.M., E-mail: ntwaeab@ufs.ac.za [Department of Physics, University of the Free State, Private bag X 13, Phuthaditjaba 9866, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Pitale, Shreyas S.; Swart, H.C. [Department of Physics, University of the Free State, Private bag X 13, Phuthaditjaba 9866, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth, ZA 6031 (South Africa); Mothudi, B.M. [Department of Physics, University of South Africa, P.O Box 392, Pretoria, ZA 6031 (South Africa)

    2012-05-15

    Combustion method was used in this study to prepare BaAl{sub 2}O{sub 4}:Eu{sup 2+} phosphors co-doped with different trivalent rare-earths (Re{sup 3+}=Dy{sup 3+}, Nd{sup 3+}, Gd{sup 3+}, Sm{sup 3+}, Ce{sup 3+}, Er{sup 3+}, Pr{sup 3+} and Tb{sup 3+}) ions at an initiating temperature of 600 Degree-Sign C. The phosphors were annealed at 1000 Degree-Sign C for 3 h. As confirmed from the X-ray diffraction (XRD) data, both as prepared and post annealed samples crystallized in the well known hexagonal structure of BaAl{sub 2}O{sub 4}. All samples exhibited bluish-green emission associated with the 4f{sup 6}5d{sup 1}{yields}4f{sup 7} transitions of Eu{sup 2+} at {approx}500 nm. Although the highest intensity was observed from Er{sup 3+} co-doping, the longest afterglow (due to trapping and detrapping of charge carriers) was observed from Nd{sup 3+} followed by Dy{sup 3+} co-doping. The traps responsible for the long afterglow were studied using thermoluminescence (TL) spectroscopy.

  4. Verwey Transition under Oxygen Loading in RBaFe 2O 5+ w ( R=Nd and Sm)

    Science.gov (United States)

    Karen, P.; Woodward, P. M.; Santhosh, P. N.; Vogt, T.; Stephens, P. W.; Pagola, S.

    2002-09-01

    Double-cell perovskites RBaFe 2O 5+ w ( R= Nd and Sm) are synthesized in the -0.03Sm atom than for R=Nd. The discontinuity of the SmBaFe 2O 5+ w transition also persists into much higher levels of the oxygen nonstoichiometry w than for the R=Nd variant. Whereas 3D-charge-ordered SmBaFe 2O 5.00 is isostructural with TbBaFe 2O 5.00 adopting space group Pmma, NdBaFe 2O 5.00 undergoes a more profound structural change upon entering the charge-ordered state, the structure of which is refined in the P2 1ma symmetry from high-resolution X-ray synchrotron diffraction data.

  5. Smøremekanismer ved mekanisk formgivning

    DEFF Research Database (Denmark)

    Bech, Jakob Ilsted; Bay, Niels; Eriksen, Morten

    1997-01-01

    I dette arbejde undersøges den Mikro Plasto Hydrodynamiske smøremekanisme som optræder ved plastisk formgivning, når hydrostatisk indfanget smøremiddel i overfladelommer trænger ud i den omgivende kontakt, og skaber lokale smørefilm mellem emne og værktøj.Smøremekanismen observeres og videofilmes...

  6. Dielectric function of SmS

    International Nuclear Information System (INIS)

    The zone-center longitudinal optical phonon of semiconducting SmS shows a 10% softening with respect to that of EuS. This result confirms the lattice-dynamical model prediction and provides first experimental evidence for the existence of an anomalous dipolar charge deformability of the Sm2+ ion in SmS. (author)

  7. Octupole correlations in 143 Ba and 147 Pr

    International Nuclear Information System (INIS)

    High spin states in neutron-rich odd-Z 143,145 Ba nuclei have been investigated from the study of prompt γ-rays in the spontaneous fission of 252 Cf. Alternating parity bands are identified for the first time in 145 Ba and extended in 143 Ba. A new side band with equal, constant dynamic and kinematic moments of inertia equal to the rigid body value, as found in superdeformed bands, is discovered in 145 Ba. Enhanced E1 transitions between the negative- and positive-parity bands in these nuclei give evidence for strong octupole deformation in 143 Ba and in 145 Ba. These collective bands show competition and co-existence between symmetric and asymmetric shapes in 145 Ba. The first evidence is found for crossing M1 and E1 transitions between the s = +i and s = -i doublets in 143 Ba. Neutron-rich 147 Pr also was studied in the spontaneous fission of 252 Cf. Possible parity doublets observed in 147 Pr with N = 88 indicate that neutron-rich 59147 Pr88 nucleus exhibits strong octupole correlations like those observed in the 58146 Ce88 core. (authors)

  8. Excited states in 146Sm and 147Sm

    International Nuclear Information System (INIS)

    The sup(144,146)Nd(α,xn) and sup(146,148)Nd(3He,xn) reactions with Esub(α) = 20 - 43 MeV and E3sub(He) = 19 - 27 MeV are used to investigate excited states in the isotopes 146Sm and 147Sm. The experiments involve measurements of singles γ-ray spectra and conversion electron spectra, γ-ray angular distributions and three parameter (E sub(γ)E sub(γ) time) coincidences. From these experiments information is obtained for states with spin up to I = 13+ and I = 27/2-, respectively, These states are interpeted within the framework of the cluster-vibration model (CVM) as well as the shell model. (author)

  9. Excited states in 146Sm and 147Sm

    Science.gov (United States)

    Kownacki, J.; Sujkowski, Z.; Hammarén, E.; Liukkonen, E.; Piiparinen, M.; Lindblad, Th.; Ryde, H.; Paar, V.

    1980-03-01

    The 144, 146Nd(α, χn) and 146,148Nd( 3He, χn) reactions with Eα = 20-43 MeV and E3He , = 19-27 MeV are used to investigate excited states in the isotopes 146Sm and 147Sm. The experiments involve measurements of singles γ-ray spectra and conversion electron spectra, γ-ray angular distributions and three-parameter ( Eγ- Eγ-time) coincidences. From these experiments information is obtained for states with spin up to I = 13 +and I = {27}/{2}-, respectively. These states are interpreted within the framework of the cluster-vibration model (CVM) as well as the shell model. In the latter approach, the energies of several well established states, in both isotopes, are calculated using empirical singleparticle energies, empirical two-particle interaction matrix elements and angular momentum algebra. The average deviation between the calculated and the experimental energies is less than 100 keV. The CVM calculations involve the coupling of a three-particle neutron cluster to the quadrupole vibration of the core. For 147Sm, these calculations reproduce the observed sequence of states based on the I π = {7}/{2}- ground state, as well as the sequence of states based on the I π = {13}/{2}+ excited state. The CVM calculations also reproduce the ground band in 146Sm, while for the negative parity states based on the cluster (f {7}/{2}i {13}/{2}) 3 --10 - an additional shift in energy is expected due to the mixing with octupole phonons.

  10. Probing the Metal-Insulator Transition in BaTiO3 by Electrostatic Doping

    Science.gov (United States)

    Raghavan, Santosh; Zhang, Jack Y.; Shoron, Omor F.; Stemmer, Susanne

    2016-07-01

    The metal-to-insulator transition in BaTiO3 is investigated using electrostatic doping, which avoids effects from disorder and strain that would accompany chemical doping. SmTiO3/BaTiO3/SrTiO3 heterostructures are doped with a constant sheet carrier density of 3 ×1014 cm-2 that is introduced via the polar SmTiO3/BaTiO3 interface. Below a critical BaTiO3 thickness, the structures exhibit metallic behavior with high carrier mobilities at low temperatures, similar to SmTiO3/SrTiO3 interfaces. Above this thickness, data indicate that the BaTiO3 layer becomes ferroelectric. The BaTiO3 lattice parameters increase to a value consistent with a strained, tetragonal unit cell, the structures are insulating below ˜125 K , and the mobility drops by more than an order of magnitude, indicating self-trapping of carriers. The results shed light on the interplay between charge carriers and ferroelectricity.

  11. Influence of preparation conditions on 211 particle refinement in YBCO bulk superconductors with Ce addition

    Energy Technology Data Exchange (ETDEWEB)

    Diko, Pavel, E-mail: dikos@saske.sk; Volochová, Daniela; Radušovská, Monika; Zmorayová, Katarína; Šefčiková, Martina; Antal, Vitalij; Jurek, Karel; Jirsa, Miloš; Kováč, Jozef

    2013-11-15

    Highlights: •CeO{sub 2} causes coarsening of Y211 particles in nominal composition Y{sub 1.5}Ba{sub 2}Cu{sub 3}O{sub x}. •Y211 particles grow during sintering at 940 °C. •High local density of Y211 particles hinders their growth at sintering stage. •Addition of BaCeO{sub 3} leads to smaller Y211 particles. •Skeleton of Y211 particles prevents pollution of grown samples. -- Abstract: The influence of CeO{sub 2} and BaCeO{sub 3} addition and the influence of processing conditions on Y{sub 2}BaCuO{sub 5} (Y211) particle size and particle distribution in melt-processed YBa{sub 2}Cu{sub 3}O{sub 7}/Y{sub 2}BaCuO{sub 5} (Y123/Y211) bulk superconductors with nominal composition Y{sub 1.5}Ba{sub 2}Cu{sub 3}O{sub x} was investigated. Ce dissolved in the peritectic melt can actively hinder the Y211 particle growth by the Ostwald ripening process at melting stage. At sintering of intensively milled samples, Y211 particles in the charge free of CeO{sub 2} are smaller than Y211 particles formed in the charge with CeO{sub 2} addition and this behaviour can be related to the melt formation around added CeO{sub 2}. The Y211 particle refinement in the mildly milled samples with large Y123 particles in the pressed green bodies is caused by very dense Y211 skeleton resistant to melt formation at the sintering stage. This skeleton is a barrier for pollution of the sample from the substrate and from the seed. BaCeO{sub 3} added instead CeO{sub 2} causes significant Y211 particle refinement also in the samples with homogenously distributed Y211 particles.

  12. Absolute photoneutron cross sections of Sm isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Gheorghe, I.; Glodariu, T. [National Institute for Physics and Nuclear Engineering Horia Hulubei, str. Atomistilor nr. 407 (Romania); Utsunomiya, H. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Filipescu, D. [Extreme Light Infrastructure - Nuclear Physics, str. Atomistilor nr. 407, Bucharest-Magurele, P.O.BOX MG6 and National Institute for Physics and Nuclear Engineering Horia Hulubei, str. Atomistilor nr. 407 (Romania); Nyhus, H.-T.; Renstrom, T. [Department of Physics, University of Oslo, N-0316 Oslo (Norway); Tesileanu, O. [Extreme Light Infrastructure - Nuclear Physics, str. Atomistilor nr. 407, Bucharest-Magurele, P.O.BOX MG6 (Romania); Shima, T.; Takahisa, K. [Research Center for Nuclear Physics, Osaka University, Suita, Osaka 567-0047 (Japan); Miyamoto, S. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori, Hyogo 678-1205 (Japan)

    2015-02-24

    Photoneutron cross sections for seven samarium isotopes, {sup 144}Sm, {sup 147}Sm, {sup 148}Sm, {sup 149}Sm, {sup 150}Sm, {sup 152}Sm and {sup 154}Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

  13. Formation of stacking faults and their correlation with flux-pinning and critical current density for Sm-doped YBa2Cu3O7- films

    Energy Technology Data Exchange (ETDEWEB)

    Wee, Sung Hun [ORNL; Specht, Eliot D [ORNL; Cantoni, Claudia [ORNL; Zuev, Yuri L [ORNL; Maroni, V. A. [Argonne National Laboratory (ANL); Wong-Ng, W. [National Institute of Standards and Technology (NIST); Liu, G. [National Institute of Standards and Technology (NIST); Haugan, T. J. [Air Force Research Laboratory; Goyal, Amit [ORNL

    2011-01-01

    A correlation between flux-pinning characteristics and stacking faults (SFs) formed by Sm substitution on Y and Ba sites was found in Sm-doped YBa2Cu3O7- (YBCO) films. It was confirmed that 223 type SFs, Y2Ba2Cu3Ox, composed of extra Y and O planes aligned parallel to the ab-planes formed via Sm substitution on the Y site and increased in number with increasing Sm doping on the Ba site. The number density of 223 SFs is correlated strongly with the enhancement in ab-plane correlated flux-pinning, resulting in a sharpening of the H ab peak in the plot of critical current density versus magnetic field orientation.

  14. Large-sized SmBCO single crystals with T sub c over 93 K grown in atmospheric ambient by crystal pulling

    CERN Document Server

    Yao Xin; Shiohara, Y

    2003-01-01

    Sm sub 1 sub + sub x Ba sub 2 sub - sub x Cu sub 3 O sub z (SmBCO) single crystals were grown under atmospheric ambient by the top-seeded solution growth method. Inductively coupled plasma results indicate that there is negligible Sm substitution for Ba sites in the grown SmBCO crystals, although they crystallized from different Ba-Cu-O solvents with a wide composition range (Ba/Cu ratio of 0.5-0.6). As a result, these crystals show high superconducting critical transition temperature values (T sub c) of over 93 K with a sharp transition width after oxygenation. A large-sized crystal with an a-b plane of 23 x 22 mm sup 2 and a c-axis of 19 mm was obtained at a high growth rate of nearly 0.13 mm h sup - sup 1. In short, with more controllable thermodynamic parameters, SmBCO single crystals can readily achieve both large size and high superconducting properties. (rapid communication)

  15. Thickness dependence of Ic and Jc of LTG-SmBCO coated-conductor on IBAD-MgO tapes

    International Nuclear Information System (INIS)

    We have reported SmBa2Cu3Oy (SmBCO) films on single crystalline substrates prepared by low-temperature growth (LTG) technique. The LTG-SmBCO films showed high critical current densities in magnetic fields compared with conventional SmBCO films prepared by pulsed laser deposition (PLD) method. In this study, to enhance critical current (Ic) in magnetic field, we fabricated thick LTG-SmBCO films on metal substrates with ion-beam assisted deposition (IBAD)-MgO buffer and estimated the Ic and Jc in magnetic fields. All the SmBCO films showed c-axis orientation and cube-on-cube in-plane texture. Tc of the LTG-SmBCO films were 93.1-93.4 K. Jc and Ic of a 0.5 μm-thick SmBCO film were 3.0 MA/cm2 and 150 A/cm-width at 77 K in self-field, respectively. Those of a 2.0 μm-thick film were 1.6 MA/cm2 and 284 A/cm-width respectively. Although Ic increased with the film thickness increasing up to 2 μm, the Ic tended to be saturated in 300 A/cm-width. From a cross sectional TEM image of the SmBCO film, we recognized a-axis oriented grains and 45o grains and Cu-O precipitates. Because these undesired grains form dead layers, Ic saturated above a certain thickness. We achieved that Ic in magnetic fields of the LTG-SmBCO films with a thickness of 2.0 μm were 88 A/cm-width at 1 T and 28 A/cm-width at 3 T.

  16. γ -soft Ba146 and the role of nonaxial shapes at N90

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A. J.; Lister, C. J.; McCutchan, E. A.; Albers, M.; Ayangeakaa, A. D.; Bertone, P. F.; Carpenter, M. P.; Chiara, C. J.; Chowdhury, P.; Clark, J. A.; Copp, P.; David, H. M.; Deo, A. Y.; DiGiovine, B.; D' Olympia, N.; Dungan, R.; Harding, R. D.; Harker, J.; Hota, S. S.; Janssens, R. V. F.; Kondev, F. G.; Liu, S. H.; Ramayya, A. V.; Rissanen, J.; Savard, G.; Seweryniak, D.; Shearman, R.; Sonzogni, A. A.; Tabor, S. L.; Walters, W. B.; Wang, E.; Zhu, S.

    2016-01-01

    Low-spin states in the neutron-rich, N=90 nuclide Ba146 were populated following β decay of Cs146, with the goal of clarifying the development of deformation in barium isotopes through delineation of their nonyrast structures. Fission fragments of Cs146 were extracted from a 1.7-Ci Cf252 source and mass selected using the CAlifornium Rare Ion Breeder Upgrade (CARIBU) facility. Low-energy ions were deposited at the center of a box of thin β detectors, surrounded by a highly efficient high-purity Ge array. The new Ba146 decay scheme now contains 31 excited levels extending up to ~2.5 MeV excitation energy, double what was previously known. These data are compared to predictions from the interacting boson approximation (IBA) model. It appears that the abrupt shape change found at N=90 in Sm and Gd is much more gradual in Ba and Ce, due to an enhanced role of the γ degree of freedom.

  17. Synthesis and characterization of rare earth and transition metal doped BaMgF{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Janssens, S. [Industrial Research Limited, PO Box 31310, Lower Hutt 5040 (New Zealand); MacDiarmid Institute, SCPS, Victoria University of Wellington, PO Box 600, Wellington 6012 (New Zealand); Williams, G.V.M., E-mail: grant.williams@vuw.ac.nz [MacDiarmid Institute, SCPS, Victoria University of Wellington, PO Box 600, Wellington 6012 (New Zealand); Clarke, D. [Industrial Research Limited, PO Box 31310, Lower Hutt 5040 (New Zealand)

    2013-02-15

    BaMgF{sub 4} nanoparticles doped with Ce{sup 3+}, Eu{sup 3+}, Mn{sup 2+}, and Nd{sup 3+} have been successfully synthesized using a reverse microemulsion method. They form nanorods that aggregate into 'moustache' shaped clusters. All doped samples show photoluminescence where the Ce{sup 3+} and Eu{sup 3+} photoluminescence spectra are consistent with substitution onto different crystal sites, while only a single site was found for the Mn{sup 2+} doped sample. Mn{sup 2+} was successfully sensitized by Ce{sup 3+} in BaMgF{sub 4}:Mn{sup 2+}:Ce{sup 3+} nanoparticles. The Ce{sup 3+} PL lifetimes are strongly wavelength dependent, which could be due to different Ce{sup 3+} sites with different PL lifetimes as well as energy transfer between Ce{sup 3+} sites. Transparent thick polymer films containing nanoparticles have been made. The appearance of photoluminescence in rare earth and transition metal doped BaMgF{sub 4} nanoparticles and the ability to make transparent thick films means that the BaMgF{sub 4} nanoparticles have a range of potential applications that include optical amplification. - Highlights: Black-Right-Pointing-Pointer BaMgF{sub 4} nanorods synthesized using a reverse microemulsion method. Black-Right-Pointing-Pointer BaMgF{sub 4} nanorods successfully doped with luminescent ions. Black-Right-Pointing-Pointer Ce{sup 3+} and Eu{sup 3+} ions occupy two distinct crystal sites. Black-Right-Pointing-Pointer Efficient energy transfer from Ce{sup 3+} to Mn{sup 2+} is observed. Black-Right-Pointing-Pointer Transparent nanoparticle/PMMA polymer films were made.

  18. Recombination processes in ZnS:Sm

    Science.gov (United States)

    Światek, K.; Godlewski, M.; Hommel, D.

    1991-04-01

    The excitation processes of Sm intraion photoluminescence (PL) in ZnS are discussed on the basis of optical studies. The excitation spectra of Sm3+ (4G5/2-->6H5/2) intraion emission indicate that the Sm3+-->Sm2++hVB photoionization (PI) channel is an active PL excitation (PLE) mechanism. It is proposed that following the PI transition a Sm-bound exciton is formed, which interposes in PLE. The strong temperature quenching of the 4G5/2-->6H5/2 emission under PI excitation is explained as being the consequence of a thermal release of holes from the Sm-bound excitons.

  19. Sierra/SM theory manual.

    Energy Technology Data Exchange (ETDEWEB)

    Crane, Nathan Karl

    2013-07-01

    Presented in this document are the theoretical aspects of capabilities contained in the Sierra/SM code. This manuscript serves as an ideal starting point for understanding the theoretical foundations of the code. For a comprehensive study of these capabilities, the reader is encouraged to explore the many references to scientific articles and textbooks contained in this manual. It is important to point out that some capabilities are still in development and may not be presented in this document. Further updates to this manuscript will be made as these capabilites come closer to production level.

  20. Urheilutapahtuman ilmesuunnittelu : Judo SM2011

    OpenAIRE

    Leppänen, Nette

    2013-01-01

    Opinnäytetyössä käsitellään visuaalisen ilmeen suunnittelua urheilutapahtumalle. Opinnäytetyön tavoitteena oli suunnitella Judon SM2011-kisoille tapahtumailme, jolla tavoitetaan potentiaalinen kisayleisö sekä sponsorit, ja jonka avulla kasvatetaan myös lajin tunnettavuutta yleisellä tasolla. Koska kisoilla ei tähän mennessä ole ollut varsinaista kisatunnusta tai muuta graafista ilmettä, suunnittelu lähtee puhtaalta pöydältä, ottaen kuitenkin huomioon asiakkaan asettamat reunaehdot sekä judon ...

  1. New NaSrPO$_4$:Sm$^{3+}$ phosphor as orange-red emitting material

    Indian Academy of Sciences (India)

    KUN-HSIEN CHEN; MIN-HANG WENG; RU-YUAN YANG; CHENG-TANG PAN

    2016-09-01

    Sm$^{3+}$-activated NaSrPO4 phosphors could be efficiently excited at 403 nm, and exhibited a bright red emission mainly including four wavelength peaks of 565, 600, 646 and 710 nm. The highest emission intensity was foundfor NaSr$_{1−x}$PO$_{4}$:$x$Sm$^{3+}$ with a composition of $x = 0.007$. Concentration quenching was observed as the composition of $x$ exceeds 0.007. The decay time values of NaSr1−xPO4:xSm3+ phosphors range from around 2.55 to 3.49 ms. NaSr$_{1−x}$PO$_{4}$:$x$Sm$^{3+}$ phosphor shows a higher thermally stable luminescence and its thermal quenching temperature$T_{50}$ was found to be 350$^{\\circ}$C, which is higher than that of commercial YAG:Ce$^{3+}$ phosphor and ZnS:(Al, Ag) phosphor. Because NaSr$_{1−x}$PO$_{4}$:$x$Sm$^{3+}$ phosphor features a high colour-rendering index and chemical stability, it is potentially useful as a new scintillation material for white light-emitting diodes.

  2. The influence of impurity on the critical thickness of the CeO2 buffer layer for coated conductors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The lattice parameters, band structure, density of state and elastic constant of RE-doped CeO2 (RE=Sm, Gd, Dy), the buffer material for coated HTS conductors, are calculated using the plane-wave method with pseudopotentials based on the density functional theory (DFT) of first-principle. The rule and mechanism of the effect of rare earth impurity on the critical thickness of the CeO2 buffer layer are investigated. It is found that, in the range of the calculation, the changes of the lattice volume V and elastic constant E of CeO2 with the impurity are mainly determined by the increased electrons ne of the system. The relationship of the elastic constant E and increased electrons ne is established. It is indicated that the critical thickness of the CeO2 single buffer layer doped with Sm, Gd, and Dy may be enhanced by 22%, 43% and 33%, respectively.

  3. Dielectric function of SmS

    International Nuclear Information System (INIS)

    The dielectric response function of SmS and SmAs has been determined via a Kramers-Kronig transformation of the room temperature reflectivity in the range from 10-2 eV to 22 eV. In SmS the assignment of optical transitions, including those from the (S) 3s core level, has been corroborated by the corresponding ones of SmAs. Reductions of the 4f binding energy are revealed in optical f→d transitions as compared to x-ray photoemission data. (author)

  4. Phase equilibria in SmS-In2S3, SmSe-In23Se3 and SmTe-In2Te3 systems

    International Nuclear Information System (INIS)

    Phase equilibria are studied for the first time and state diagrams of SmS-In2S3, SmSe-In23Se3 and SmTe-In2Te3 systems are plotted for the first time using physicochemical analysis techniques. Formations of SmIn2S4, SmIN-4S7, SmIn2Se4 and SmIn2Te4 composition samarium chalcoindates and limited ranges of solubility characteristic for indium sesqui-chalcogenites are determined. SmIn2S4 compound is melted congruently under 1570 K, while SmIn4S7, SmIn2Se4 and SmIn2Te4 are formed by peritectic reaction

  5. Nitrate ion association with Sm3+ ion

    International Nuclear Information System (INIS)

    A solvent extraction method with TBP as an extractant was used for the determination of the stability constants K10 for the SmNO32+ complex, for different least approach distances aa of ions. It was established that aa=6.5A for SmNO32+. (Author)

  6. Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson at muon collider

    Indian Academy of Sciences (India)

    Jai Kumar Singhal; Sardar Singh; Ashok K Nagawat

    2007-06-01

    We explore the possibility of distinguishing the SM-like MSSM Higgs boson from the SM Higgs boson via Higgs boson pair production at future muon collider. We study the behavior of the production cross-section in SM and MSSM with Higgs boson mass for various MSSM parameters tan and A. We observe that at fixed CM energy, in the SM, the total cross-section increases with the increase in Higgs boson mass whereas this trend is reversed for the MSSM. The changes that occur for the MSSM in comparison to the SM predictions are quantified in terms of the relative percentage deviation in cross-section. The observed deviations in cross-section for different choices of Higgs boson masses suggest that the measurements of the cross-section could possibly distinguish the SM-like MSSM Higgs boson from the SM Higgs boson.

  7. On the role of Sm in solidification of Al-Sm metallic glasses

    CERN Document Server

    Bokas, G B; Perepezko, J H; Szlufarska, I

    2016-01-01

    During the solidification of Al-Sm metallic glasses the evolution of the supercooled liquid atomic structure has been identified with an increasing population of icosahedral-like clusters with increasing Sm concentration. These clusters exhibit slower kinetics compared to the remaining clusters in the liquid leading to enhanced amorphous phase stability and glass forming ability (GFA). Maximum icosahedral-ordering and atomic packing density have been found for the Al90Sm10 and Al85Sm15 alloys, respectively, whereas minimum cohesive energy has been found for the Al93Sm7 which is consistent with the range of compositions (from Al92Sm8 to Al84Sm16) found experimentally with high GFA.

  8. Study on rare earth/alkaline earth oxide-doped CeO2 solid electrolyte

    Institute of Scientific and Technical Information of China (English)

    YAN Kai; ZHEN Qiang; Song Xiwen

    2007-01-01

    Five types of rare earth/alkaline earth oxide-doped CeO2 superfine-powders were synthesized by a low-temperature combustion technique. The relevant solid electrolyte materials were also sintered by pressureless sintering at different temperatures. The results of X-ray diffraction and transmission electron microscopy showed that the grain size of the powders was approximately 20-30 nm, and rare earth/alkaline earth oxides were completely dissolved into ceria-based solid solution with fluorite structure. The electrical conductivities of the Sm2O3-CeO2 system were measured by the ac impedance technique in air at temperatures ranging from 513-900℃. The results indicated that the ionic conductivities of Sm0.20Ce0.8O1.875 solid electrolyte increase with increasing sintering temperature, and the relationship between the conductivities and measuring temperature obeys the Arrhenius equation. Then the Sm2O3-CeO2 material was further doped with other rare earth/alkaline earth oxide, and the conductivities improve with the effective index.

  9. Cs3Sm7Se12

    Directory of Open Access Journals (Sweden)

    Christof Schneck

    2012-01-01

    Full Text Available The title compound, tricaesium heptasamarium(III dodecaselenide, is setting a new starting point for realization of the channel structure of the Cs3M7Se12 series, now with M = Sm, Gd–Er. This Cs3Y7Se12-type arrangement is structurally based on the Z-type sesquiselenides M2Se3 adopting the Sc2S3 structure. Thus, the structural set-up of Cs3Sm7Se12 consists of edge- and vertex-connected [SmSe6]9− octahedra [dØ(Sm3+ – Se2− = 2.931 Å], forming a rock-salt-related network [Sm7Se12]3− with channels along [001] that are apt to take up monovalent cations (here Cs+ with coordination numbers of 7 + 1 for one and of 6 for the second cation. The latter cation has a trigonal–prismatic coordination and shows half-occupancy, resulting in an impossible short distance [2.394 (4 Å] between symmetrically coupled Cs+ cations of the same kind. While one Sm atom occupies Wyckoff position 2b with site symmetry ..2/m, all other 11 crystallographically different atoms (namely 2 × Cs, 3 × Sm and 6 × Se are located at Wyckoff positions 4g with site symmetry ..m.

  10. Temperature and host dependence of the transition interference between f–f and f–d transitions of Sm2+ in matlockites

    International Nuclear Information System (INIS)

    The absorption spectra of Sm2+ doped in MFX (M=Sr, Ba; X=Cl, Br) crystals were studied within the range of 20,000–35,000 cm−1 as a function of temperature and host. The absorption bands observed were described with a simple model developed by Wood and Kaiser using group theory. The temperature and host dependence on the 7F0→5D3 Fano resonance lines were investigated. BaFCl:Sm2+ system showed a “normal” 7F0→5D3 transition at 4 K in spite of similar crystal structure and absorption profile with other MFX hosts. New Fano resonances were observed in the absorption spectra at higher energies (23,000–25,000 cm−1) for all MFX:Sm2+ systems at 4 K which persist up to room temperature. Preliminary energy level calculation showed that these resonance lines involve the interaction between higher excited 5LJ states of 4f6 configuration and 4f55d1 configuration. - Highlights: • The absorption spectra of Sm2+ doped in MFX (M=Sr, Ba; X=Cl, Br) crystals within the range of as a function of temperature and host. • The absorption bands described with a simple model developed by Wood and Kaiser using group theory. • BaFCl:Sm2+ system showed a “normal” 7F0→5D3 transition at 4 K in spite of similar crystal structure and absorption profile with other MFX hosts. • New Fano resonances observed in the absorption spectra at higher energies (23,000–25,000 cm−1) for all MFX:Sm2+ systems at 4 K which persist up to room temperature

  11. Epitaxial Cubic Ce2O3 Films via Ce-CeO2 Interfacial Reaction.

    Science.gov (United States)

    Stetsovych, Vitalii; Pagliuca, Federico; Dvořák, Filip; Duchoň, Tomáš; Vorokhta, Mykhailo; Aulická, Marie; Lachnitt, Jan; Schernich, Stefan; Matolínová, Iva; Veltruská, Kateřina; Skála, Tomáš; Mazur, Daniel; Mysliveček, Josef; Libuda, Jörg; Matolín, Vladimír

    2013-03-21

    Thin films of reduced ceria supported on metals are often applied as substrates in model studies of the chemical reactivity of ceria based catalysts. Of special interest are the properties of oxygen vacancies in ceria. However, thin films of ceria prepared by established methods become increasingly disordered as the concentration of vacancies increases. Here, we propose an alternative method for preparing ordered reduced ceria films based on the physical vapor deposition and interfacial reaction of Ce with CeO2 films. The method yields bulk-truncated layers of cubic c-Ce2O3. Compared to CeO2 these layers contain 25% of perfectly ordered vacancies in the surface and subsurface allowing well-defined measurements of the properties of ceria in the limit of extreme reduction. Experimentally, c-Ce2O3(111) layers are easily identified by a characteristic 4 × 4 surface reconstruction with respect to CeO2(111). In addition, c-Ce2O3 layers represent an experimental realization of a normally unstable polymorph of Ce2O3. During interfacial reaction, c-Ce2O3 nucleates on the interface between CeO2 buffer and Ce overlayer and is further stabilized most likely by the tetragonal distortion of the ceria layers on Cu. The characteristic kinetics of the metal-oxide interfacial reactions may represent a vehicle for making other metastable oxide structures experimentally available.

  12. Electronic configurations of Sm2+ in SmS and SmB6, and electrical properties

    International Nuclear Information System (INIS)

    In Dirac's theory the 4f shell is divided into two subshells: 4f/sub 5/2/ with six quantum states and 4f/sub 7/2/ with eight quantum states. Assuming that these two subshells can be filled up successively, we had successfully obtained the saturation magnetic moment of the garnets Ln3Fe5O12. This study is devoted to establish the role of the subshells in the case of SmS phase transformation under pressure P. Particularly for Sm2+ the low spin configuration 4f/sub 5/2/6 4f/sub 7/2/0 which with six 4f electrons has a filled subshell 4f/sub 5/2/ leading to a zero magnetic moment. But as the insulator in equilibrium metal I in equilibrium M transition exhibited with this phase transition, is explained through a valence change, we first consider the localized electron model proposed in the case of Fe3O4 to show that large variations of electrical resistivity of SmS and SmB6 also can be understood through this model. A result which allows us to consider the ion Sm2+ in both phases of SmS. 1 figure

  13. Interaction in the systems Bi2S3-SmS and Bi2S3-Sm2S3

    International Nuclear Information System (INIS)

    Methods of physicochemical analysis are used to study Bi2S3-SmS (1) and Bi2S3-Sm2S3 (2) systems that are quasibinary cross sections of Sm-Bi-S ternary system. Formation of ternary phases of SmBi2S4, SmBi4S7 (in system 1) composition and of SmBiS3 composition (in system 2) is stated. The compounds are crystallized in stibnite type rhombic singony: SmBi2S4: a = 12.55; b = 14.11; c = 4.12 A; SmBi4S7: a = 12.61; b = 14.20, c = 4.70 A, SmBiS3: a 11.15, b = 11.77, c = 3.85 A. SmS(Sm2S3) solubility in Bi2S3 at 300 K is 3 mol.%

  14. Thermodynamic properties of Sm2S3 and SmS2 within wide temperature range

    International Nuclear Information System (INIS)

    For the first time using the mixing method in a wide temperature range inthalpies of Sm2S3 and SmS2 are determined. An intense increase of Sm2S3 enthalpy is observed in the high temperature range and the melting point for this compound is determined. The basic thermodynamic characteristics (enthalpy, thermal capacity, entropy, reduced Gibbs energy) of studied sulfides are calculated

  15. CE-BEMS

    DEFF Research Database (Denmark)

    Mohamed, Nader; Lazarova-Molnar, Sanja; Al-Jaroodi, Jameela

    2016-01-01

    and costs savings in smart buildings significantly depend on the monitoring and control methods used in the installed BEMS. This paper proposes a Cloud-Enabled BEMS (CE-BEMS) for Smart Buildings. This system can utilize cloud computing to provide enhanced management mechanisms and features for energy...... savings in smart buildings. This system is connected to the cloud to have access to a number of advanced cloud-based services to enhance energy management in smart buildings. In this paper, we discuss the current limitations of BEMS, the conceptual design of the proposed system, and the advantages...

  16. Effects of Cerium Doping at Ti Sites and Europium Doping at Ba Sites on Dielectric Properties of BaTiO3 Ceramics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Two special rare earth elements cerium and europium were chosen to conduct chemical modification of the BaTiO3 structure. The cold-pressing ceramic processing technique was used to prepare barium titanate ceramics doped with Ce at Ti sites and with Eu at Ba sites on the base of formulas Ba(Ti1-xCex)O3(x=0.05, 0.10)(CBT) and(Ba1-yEuy)Ti1-y/8O3(y=0.05, 0.10)(EBT). Associated with structures and microstructures, the effects of cerium and europium doping on dielectric properties of BaTiO3 ceramics were discussed. The CBT ceramics exhibit a pseudo-cubic perovskite structure, while the EBT ceramics exhibit a tetragonal perovskite structure with the exception of the existence of a small percentage of the Eu2Ti2O7 phase. The Curie peak of BaTiO3 shifts towards room temperature at rates of 3 ℃/mol Ce atoms and 10 ℃/mol Eu atoms(Eu≤5%), respectively. Compared with the CBT ceramics, the EBT ceramics show significant advantages, such as a narrow fine grain size distribution(1 μm), a lower porosity and a higher density(5.85 g/cm3), more stable dielectric-temperature dependence(ε'=1600-1800 at t<50 ℃) and a lower dissipation factor(<0.05). The stability of dielectric constant with frequency in BaTiO3 can extend to 107 Hz due to Ce and Eu doping.

  17. About defect structure in SmS

    International Nuclear Information System (INIS)

    One managed to obtain the experimental dependence of the conduction band electron concentration on the sizes of X-ray radiation coherent scattering regions. The curve analysis was based on the previously elaborated concentration model of SmS energy spectrum. The impurity donor levels in SmS were shown to correlate with samarium defective ions located at the boundaries of the coherent scattering regions

  18. Fusiblility diagram of the SmS-Sm2S3 system

    International Nuclear Information System (INIS)

    Isobaric fusibility diagram of a part of the binary Sm-S system lying between SmS-Sm2S3 compounds within 1500-2100 deg C temperature range was built on the basis of the data of physicochemical analysis (thermal, annealing and quenching, microstructural, durometric and X-ray phase). Consistency of data from different methods indicates at the reliability and confidence of the presented diagram. The analogy of Sm-S system fusibility diagram with La-S system diagram is noted

  19. Provably-secure (Chinese government) SM2 and simplified SM2 key exchange protocols.

    Science.gov (United States)

    Yang, Ang; Nam, Junghyun; Kim, Moonseong; Choo, Kim-Kwang Raymond

    2014-01-01

    We revisit the SM2 protocol, which is widely used in Chinese commercial applications and by Chinese government agencies. Although it is by now standard practice for protocol designers to provide security proofs in widely accepted security models in order to assure protocol implementers of their security properties, the SM2 protocol does not have a proof of security. In this paper, we prove the security of the SM2 protocol in the widely accepted indistinguishability-based Bellare-Rogaway model under the elliptic curve discrete logarithm problem (ECDLP) assumption. We also present a simplified and more efficient version of the SM2 protocol with an accompanying security proof. PMID:25276863

  20. 从(Sm-Sn/m-n)=(Sm+n/m+n)说开去

    Institute of Scientific and Technical Information of China (English)

    阙程柯

    2004-01-01

    @@ 在等差数列{an}中,Sn为其前n项和,则有如下性质: (Sm-Sn/m-n)=(Sm+n/m+n)(m,n∈N*,且m≠n)(1) 证明∵Sm-Sn =ma1+(1/2)m(m-1)d-na1-(1/2)n(n-1)d =(m-n)[a1+1/2(m+n-1)d], ∴(Sm-Sn/m-n)=a1+(1/2)(m+n-1)d.

  1. Structural Characterization of Sm(III)(EDTMP).

    Science.gov (United States)

    Yang, Y; Pushie, M J; Cooper, D M L; Doschak, M R

    2015-11-01

    Samarium-153 ethylenediamine-N,N,N',N'-tetrakis(methylenephosphonic acid) ((153)Sm-EDTMP, or samarium lexidronam), also known by its registered trademark name Quadramet, is an approved therapeutic radiopharmaceutical used in the palliative treatment of painful bone metastases. Typically, patients with prostate, breast, or lung cancer are most likely to go on to require bone pain palliation treatment due to bone metastases. Sm(EDTMP) is a bone-seeking drug which accumulates on rapidly growing bone, thereby delivering a highly region-specific dose of radiation, chiefly through β particle emission. Even with its widespread clinical use, the structure of Sm(EDTMP) has not yet been characterized at atomic resolution, despite attempts to crystallize the complex. Herein, we prepared a 1:1 complex of the cold (stable isotope) of Sm(EDTMP) under alkaline conditions and then isolated and characterized the complex using conventional spectroscopic techniques, as well as with extended X-ray absorption fine structure (EXAFS) spectroscopy and density functional structure calculations, using natural abundance Sm. We present the atomic resolution structure of [Sm(III)(EDTMP)-8H](5-) for the first time, supported by the EXAFS data and complementary spectroscopic techniques, which demonstrate that the samarium coordination environment in solution is in agreement with the structure that has long been conjectured.

  2. COMPARISION OF THE COLOR PROPERTIES OF COMPOUNDS Ln2Ce2O7 AND Ln2CeZrO7

    Directory of Open Access Journals (Sweden)

    B. Hablovicova

    2015-09-01

    Full Text Available Pyrochlore type pigments Ln2Ce2O7 and Ln2CeZrO7 (Ln = Nd, Sm, Gd, Dy, Er, Yb and Y prepared by solid-state reaction were investigated. Effect of rare earths and zirconium ions and calcination temperature (1400, 1500 and 1600oC for Ln2Ce2O7 and 1400, 1450 and 1500 C for Ln2CeZrO7 on their color properties in organic matrix and ceramic glazes, particle size distribution and phase composition were evaluated. The most interesting shades achieve compounds with the highest calcination temperature. Their colors depend on used rare earth ions (shades change from green, cross yellow to pink in organic mass and from green, cross yellow-green to orange in ceramic glazes, while compounds without zirconium have better color properties. Pigments Ln2Ce2O7 calcined at 1600 C are single-phase (except Yb2Ce2O7.

  3. Magnetic entropy change and large refrigerant capacity of Ce6Ni2Si3-type GdCoSiGe compound

    Institute of Scientific and Technical Information of China (English)

    Shen Jun; Zhang Hu; Wu Jian-Feng

    2011-01-01

    Magnetic entropy change (△Sm) and refrigerant capacity (RC) of Ce6Ni2Si3-type Gd6Co1.67Si2.5Ge0.5 compounds have been investigated. The Gd6Co1.67Si2.5Ge0.5 undergoes a reversible second-order phase transition at the Curie temperature TC = 296 K. The high saturation magnetization leads to a large △Sm and the maximal value of △Sm is found to be 5.9 J/kg ? K around TC for a field change of 0-5 T. A broad distribution of the △Sm peak is observed and the full width at half maximum of the △Sm peak is about 101 K under a magnetic field of 5 T. The large RC is found around TC and its value is 424 J/kg.

  4. Alkaline-earth oxide network modifier on optical properties of Ce3+-activated borogermanate glasses

    Science.gov (United States)

    Sun, Xin-Yuan; Xiao, Zhuo-Hao; Zhong, Jiu-Ping

    2015-12-01

    Transparent and colorless CeO2-activated borogermanate glasses, with the nominal composition of 25B2O3-40GeO2-14Gd2O3-1CeO2-20MO (M = Ba, Sr, Ca and Mg), were synthesized by a melt-quenching method in air. Their optical properties including the transmittance, photoluminescence (excitation and emission spectra), the luminescence decay curves, as well as the temperature-dependent emission spectra were studied in detail. The room temperature photoluminescence spectra reveal that the emission intensity of the MgO glass is about two times stronger than that of the BaO glass. The blue shift of the cut-off edge, excitation and emission spectra of Ce3+-activated borogermanate glass were clearly observed in the order of BaO, SrO, CaO and MgO. And the emission intensity of Ce3+ ions as a function of temperature range in 325-475 K was also investigated.

  5. FT-IR evaluation of SmFeAsO1-xFx (x = 0, 0.069)

    Science.gov (United States)

    Shinohara, Hajime; Kamihara, Yoichi

    2012-02-01

    Optical properties of superconducting SmFeAsO1-xFx (x=0, 0.069) were demonstrated by reflection measurement with FT- IR method. Polycrystalline SmFeAsO1-xFx samples were synthesized using two-step solid state reaction described elsewhere [New J. Phys.12, 033005 (2010)]. Purity of samples was checked by X-ray diffraction patterns using Cu K- alpha radiation. The reflection measurement was performed at the range from 9000 cm-1 to 18000 cm-1 that was corresponded to an energy region from 1.12 eV to 2.25 eV. A photoconductivity of SmFeAsO1-xFx was determined by Kramer-Kroning (KK) relation. Reflectivity and photoconductivity measurements, as well as by FT-IR, at various areas were performed to define an energy level of materials [EPL, 84 67013 (2008), and J. Phys. Soc. Jpn. 80 013707 (2011)]. Obtained photoconductivity and reflection spectra were similar to those of LaFeAsO1-xFx that was a basic compound of LnFeAsO1-xFx (Ln=La, Ce, Sm), reported by Z. G. Chen et al [Phys. Rev. B 81, 100502 (2010)]. Our result suggests that the energy band structure of SmFeAsO was affected by F-doping even in visible area. Details and temperature dependence of the reflection and photoconductivity spectra will be presented at the conference.

  6. Brillouin spectroscopy on doped SmS

    International Nuclear Information System (INIS)

    SmS becomes intermediate valent at an applied pressure of about 6.5 kbar. On the other hand, SmS doped with La or Tm is already intermediate valent at normal pressure and room temperature. The doping atoms (depending on their concentration) create new occupied states in the SmS gap which lead to the typical hybridised 4fi/4fi-1-5d1-states. The La-cation is always trivalent in LaS, whereas the Tm-cation has a valence between 2 and 3. Therefore, we expect to see a difference in the intermediate valent behaviour. A strong evidence of intermediate valence is a negative C12 and a negative Poisson's ratio. Using high-resolution Brillouin-spectroscopy we measured the phase velocity of the surface acoustic waves in the (100)-plane of Sm1-xLaxS and Sm1-xTmxS. Applying a standard fit-algorithm we calculated all three elastic constants (C11, C12 and C44) from the angular dispersion relation. To get more reliable results the compression-moduli also have been determined and linked to the elastic constants C11 and C12 in the fit model. (orig.)

  7. Coherent potential approximation treatment of the Sm valence transition in SmS induced by alloying

    International Nuclear Information System (INIS)

    The Sm valence transition, similar to the pressure-induced transition in pure SmS, has been observed in a large number of cases by substituting a trivalent rare earth, B, for Sm, thereby forming isostructural alloys with a lattice constant smaller than that of semiconducting SmS. Such substitutions are expected to exert a 'chemical' pressure which simulates the external pressure. However, divalent substitutions (Yb, Eu and Ca), although having a favourable 'size' factor, do not induce any valence transition. Accordingly, band structure effects, essentially due to the relative position of the conduction bands of SmS and BS, should also be taken into consideration. In order to clarify the role which the lattice constant and the electronic structure play in the valence transition, these alloys have been studied using the coherent potential approximation (CPA) including both the crystal field effect and the Coulomb interaction between localised and itinerant states as driving mechanisms. For Sm, the 'homogeneous' picture is considered, each Sm site having the average valence; then the Smsub(1-x)Bsub(x)S system is reduced to a binary alloy. Charge transfer between the f states of Sm and the alloy conduction band (i.e. Sm valence change) is determined self-consistently. The calculations are consistent with the experimental behaviour and allow us to understand qualitatively the variation of the critical concentration xsub(c) for the transition as a function of the difference Δa between the lattice parameters of SmS and BS. (author)

  8. Nioboaeschynite-(Ce, Ce(NbTiO6

    Directory of Open Access Journals (Sweden)

    Shaunna M. Morrison

    2012-08-01

    Full Text Available Nioboaeschynite-(Ce, ideally Ce(NbTiO6 [cerium(III niobium(V titanium(IV hexaoxide; refined formula of the natural sample is Ca0.25Ce0.79(Nb1.14Ti0.86O6], belongs to the aeschynite mineral group which is characterized by the general formula AB2(O,OH6, where eight-coordinated A is a rare earth element, Ca, Th or Fe, and six-coordinated B is Ti, Nb, Ta or W. The general structural feature of nioboaeschynite-(Ce resembles that of the other members of the aeschynite group. It is characterized by edge-sharing dimers of [(Nb,TiO6] octahedra which share corners to form a three-dimensional framework, with the A sites located in channels parallel to the b axis. The average A—O and B—O bond lengths in nioboaeschynite-(Ce are 2.471 and 1.993 Å, respectively. Moreover, another eight-coordinated site, designated as the C site, is also located in the channels and is partially occupied by A-type cations. Additionally, the refinement revealed a splitting of the A site, with Ca displaced slightly from Ce (0.266 Å apart, presumably resulting from the crystal-chemical differences between the Ce3+ and Ca2+ cations.

  9. Decay of 120Ba

    International Nuclear Information System (INIS)

    The decay of 120Ba has been studied with an on-line isotope separator. Its half-life was determined to be t1/2=24±2 s. A decay scheme is proposed, based on γ-γ, γ-X, and γ-β+ coincidence measurements, which takes account of all 16 observed γ rays. The total decay energy was measured to be QEC=50±0.3 MeV

  10. The Cloud2SM Project

    Science.gov (United States)

    Crinière, Antoine; Dumoulin, Jean; Mevel, Laurent; Andrade-Barosso, Guillermo; Simonin, Matthieu

    2015-04-01

    From the past decades the monitoring of civil engineering structure became a major field of research and development process in the domains of modelling and integrated instrumentation. This increasing of interest can be attributed in part to the need of controlling the aging of such structures and on the other hand to the need to optimize maintenance costs. From this standpoint the project Cloud2SM (Cloud architecture design for Structural Monitoring with in-line Sensors and Models tasking), has been launched to develop a robust information system able to assess the long term monitoring of civil engineering structures as well as interfacing various sensors and data. The specificity of such architecture is to be based on the notion of data processing through physical or statistical models. Thus the data processing, whether material or mathematical, can be seen here as a resource of the main architecture. The project can be divided in various items: -The sensors and their measurement process: Those items provide data to the main architecture and can embed storage or computational resources. Dependent of onboard capacity and the amount of data generated it can be distinguished heavy and light sensors. - The storage resources: Based on the cloud concept this resource can store at least two types of data, raw data and processed ones. - The computational resources: This item includes embedded "pseudo real time" resources as the dedicated computer cluster or computational resources. - The models: Used for the conversion of raw data to meaningful data. Those types of resources inform the system of their needs they can be seen as independents blocks of the system. - The user interface: This item can be divided in various HMI to assess maintaining operation on the sensors or pop-up some information to the user. - The demonstrators: The structures themselves. This project follows previous research works initiated in the European project ISTIMES [1]. It includes the infrared

  11. Resonant photoemission from SmS(100)

    International Nuclear Information System (INIS)

    A strong, sharp resonance enhancement of 4f photoemission has been observed on SmS(100) surfaces for photon energies in the region of the 4d-4f transitions at about 126 eV. The discrete final state reached via the excitation hν + 4d104f6 → 4d94f7 autoionizes primarily via a super Coster-Kronig transition of the type 4d94f7 → 4d104f5 + unbound electron. Other decay channels, e.g. Sm 5p emission, as well as a surface induce binding energy shift in the Sm3+ final state are identified and discussed. (author)

  12. Triaxiality in 146,148Sm nuclei

    International Nuclear Information System (INIS)

    Recently, attempts have been made to use the dynamic pairing plus quadrupole model to evaluate B(E2) values, B(E2) branching ratios, and low-lying energy levels for 146,148Sm nuclei, which are in poor agreement with experiment. Application of the boson expansion technique on 148Sm shows too much splitting and an incorrect order for the quintet states, while other properties have not been discussed. In the present work, 146,148Sm nuclei have been described using an asymmetric rotor model framework. The nonaxiality parameter γ has been evaluated using the energy ration E2+'/E6+. Remarkable success has been achieved in explaining the correct ordering of known low-lying energy levels, B(E2) values, and B(E2) branching ratios, which indicate that the so-called spherical nuclei may be treated as triaxial. (author). 8 refs., 9 tabs., 1 fig

  13. Specific heat in high magnetic fields. A study of the heavy-fermion systems U(Pt,Pd)3 and CeRu2Si2 and the high-Tc superconductors ReBa2Cu2O7. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    van der Meulen, H.P.

    1992-06-02

    The subject of the thesis is the study of the low-temperature electronic behavior of two classes of materials: the high-T(c) superconductor YBa2Cu3O7 with rare-earth substitutions for Y, and the heavy-fermion compounds U(Pt,Pd)3 and CeRu2Si2. The thesis is organized as follows: In chapter 2, the experimental technique for performing specific-heat measurements in high static magnetic fields are discussed. In addition, a paper on new possibilities of magnetic ripple shielding for specific heat measurements in hybrid magnets is presented. Chapter 3 is devoted to the high-T(c) superconductors of the series REBa2Cu3O7. In chapter 4, the low-temperature specific heat of REBa2Cu3O7, as studied in magnetic fields up to 5 T, is presented. The authors discuss measurements from which information about the crystal-field level schemes of the rare-earth ions can be derived. Chapter 5 is devoted to specific-heat studies in the heavy-fermion superconductor UPt3, and in the Pd-substituted U(Pt1-xPdx)3 compounds, with x=0.05 and 0.10. Chapter 6 describes the field suppression of the heavy-fermion state in CeRu2Si2.

  14. Conceptual Design Plan SM-43 Replacement Project

    Energy Technology Data Exchange (ETDEWEB)

    University of California, Los Alamos National Laboratory, SCC Project Office

    2000-11-01

    The Los Alamos National Laboratory Conceptual Design Plan for the SM-43 Replacement Project outlines plans for replacing the SM-43 Administration Building. Topics include the reasons that replacement is considered a necessity; the roles of the various project sponsors; and descriptions of the proposed site and facilities. Also covered in this proposal is preliminary information on the project schedule, cost estimates, acquisition strategy, risk assessment, NEPA strategy, safety strategy, and safeguards and security. Spreadsheets provide further detail on space requirements, project schedules, and cost estimates.

  15. OTF CCSDS SM and C Interoperability Prototype

    Science.gov (United States)

    Reynolds, Walter F.; Lucord, Steven A.; Stevens, John E.

    2008-01-01

    A presentation is provided to demonstrate the interoperability between two space flight Mission Operation Centers (MOCs) and to emulate telemetry, actions, and alert flows between the two centers. One framework uses a COTS C31 system that uses CORBA to interface to the local OTF data network. The second framework relies on current Houston MCC frameworks and ad hoc clients. Messaging relies on SM and C MAL, Core and Common Service formats, while the transport layer uses AMS. A centralized SM and C Registry uses HTTP/XML for transport/encoding. The project's status and progress are reviewed.

  16. Krager, husskader og småvildt

    DEFF Research Database (Denmark)

    Asferg, T.

    på kragers og husskaders præda-tion på hare, ager-høne og fasan med særlig fokus på perioden fra det tidlige forår til jagtsæsonens start i efteråret. Derudover er der en kort opsummering af prædationen på småfugle. Mange eksperimenter har vist, at prædation på det jagtbare småvildt kan reduceres...

  17. Rotational hysteresis in SmCo5

    International Nuclear Information System (INIS)

    Torque curves of SmCo5 sintered magnets with regularily lowered coercivity up to a maximum field H = 28 x 105 Am-1 have been registered automatically. From the observed rotational hysteresis the values of the rotational integral could be estimated in dependence on the degree of lowering of the coercivity. By comparison with theoretically calculated values for a simple nucleation model for a single crystal it follows that the mechanism of the magnetization reversal for SmCo5 magnets with lowered coercivity should be pinning of Bloch walls in the multidomain state. The absolute value of the maximum rotational hysteresis work is comparable with the maximum linear hysteresis work. (author)

  18. Ce que soigner veut dire

    OpenAIRE

    Mol, Annemarie

    2013-01-01

    Qu'est-ce que bien soigner? Dans ce livre provoquant et original, Annemarie Mol montre que ce n'est pas, comme on l'a beaucoup dit, laisser les patients choisir. À partir de l'exemple des personnes atteintes de diabète, l'auteur propose une nouvelle manière de prendre soin des personnes, qui ne les transforme pas en citoyens ou en consommateurs, mais qui les reconnaît comme corps et âmes souffrants, comme individus investis dans leur propre prise en charge, comme membres de collectifs multipl...

  19. Struktury budoucích směrovacích tabulek pro IPv6

    OpenAIRE

    Kšica, Martin

    2010-01-01

    Tato práce se zabývá strukturami budoucích směrovacích tabulek protokolu IPv6. Obsahuje základní informace o IPv6 adresách, popis hierarchického přidělování adres, multihoming, strategie přidělování IPv4/IPv6 adres, statistiky vlastností vyskytující se ve strukturách směrovacích tabulek a předpověď budoucího adresového prostoru protokolu IPv6. Součástí práce je implementace generátoru IPv6 adres, který generuje adresy podle zadané konfigurace. Současně lze v práci nalézt průzkum strategií při...

  20. Dopant Behaviours of Sm2O3 on Microstructure and Properties of Barium Zirconium Titanate Ceramics

    Institute of Scientific and Technical Information of China (English)

    王永力; 李龙土; 齐建全; 桂治轮

    2001-01-01

    The effect of Sm2O3-dopant on the sintering characteristics and dielectric properties of barium zirconium titanate ceramics (BaZrxTi1-xO3) was investigated. It is shown that trace amount of Sm2O3 can greatly affect the grain growth and densification of barium zirconium titanate ceramics during sintering. At the same time, the dielectric peak at high temperature shifts to lower temperature and that at low temperature shifts to higher temperature. The two dielectric peaks overlap with each other when the Sm2O3-dopant content varies from 0.25% to 1%, and the maximum relative dielectric constant is greatly enhanced. These effects may be attributed to the substitution actions of the rare earth element in perovskite lattice. At the doping content of 0.75%, the dielectric constant maximum of 23570 can be obtained. By adopting some proper additives, an excellent Y5V dielective material is obtained, and the room temperature properties are as follows: relative dielectric constant εRT≥23,000, dielectric loss tgδ≤0.0075 and the breakdown strength under alternating field Eb≥5 kV·mm-1.

  1. Comparison of Ce$^{3+}$ and Pr$^{3+}$ activators in alkaline-earth fluoride crystals

    OpenAIRE

    Radzhabov, E.; Nepomnyaschikh, A.

    2012-01-01

    The emission spectra of Ce$^{3+}$ or Pr$^{3+}$ doped CaF$_2$, SrF$_2$, BaF$_2$ excited by vacuum ultraviolet photons or by x-ray as well as excitation and absorption spectra in vacuum ultraviolet region (6-13 eV) were studied. The transfer of exciton energy is the main channel for Ce$^{3+}$ excitation in alkaline-earth fluorides. Three different stages of energy transfer were observed. Pr$^{3+}$ excited by two processes, slow f-f luminescence excited by excitons, fast d-f luminescence excited...

  2. Effective thickness of CeO2 buffer layer for YBCO coated conductor by advanced TFA-MOD process

    International Nuclear Information System (INIS)

    YBCO films were fabricated on PLD-CeO2/IBAD-Gd2Zr2O7/Hastelloy substrates using the advanced TFA-MOD process. The effective thickness of the CeO2 buffer layer for obtaining high Ic was investigated in short samples of YBCO films. The CeO2 buffer layer was epitaxially grown on an IBAD-Gd2Zr2O7 template tape with 18 deg. of Δφ by a reel-to-reel PLD system. The in-plane grain alignment of PLD-CeO2 buffer layers rapidly improved with the thickness and saturated at a critical thickness of 0.8 μm. The size of CeO2 grains was about 1 μm at the saturated thickness of Δφ. YBCO films with the thickness of 1 μm were deposited by the TFA-MOD on the CeO2 buffer layer with different thickness films. Improvement of the CeO2 in-plane grain alignment resulted in increase of Ic. The Ic values of 250-290 A were obtained with the CeO2 layer thicker than 0.8 μm. The CeO2 thickness, at which the intensity ratio of the BaCeO3 was saturated, corresponded to the critical thickness. From the view points of achieving higher production rates and to obtain the CeO2 Δφ value of 5 deg. as well as considering the reaction between YBCO and CeO2, the optimum thickness of the CeO2 buffer layer on the IBAD-Gd2Zr2O7 with 18 deg. of Δφ was found to be at least 0.8 μm

  3. Hydrothermal alteration of monazite-(Ce) from the Santa Maria de Itabira pegmatite district (Minas Gerais, Brazil); Alteration hydrothermale des monazites-(Ce) des pegmatites du district de Santa Maria de Itabira (Minas Gerais, Bresil)

    Energy Technology Data Exchange (ETDEWEB)

    Bilal, E.; Arias Nalini, H.; Nasraoui, M. [Ecole Nationale Superieure des Mines, 42 - Saint-Etienne (France). Dept. de Geochimie, Centre SPIN; Marciano, V.; Neves, J.M.C.; Fernandes, M.L. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. Geociencias; Fuzikawa, K. [Comissao Nacional de Energia Nuclear (CNEN), Belo Horizonte, MG (Brazil). Centro de Desenvolvimento de Tecnologia Nuclear

    1998-05-01

    Monazite-(Ce) is found in granitic pegmatites in the Santa Maria de Itabira pegmatite district (Minas Gerais, Brazil). During the magmatic stage, monazite-(Ce) seems to have had higher contents of cheralite and buttonite in the solid solution. The Th content in primary monazite-(Ce) is high and characteristic for each pegmatite body. During the late stage (albitisation), the mean LREE content in the altered zone is slightly higher and Th content is very low. The accessory mineral assemblages changed; buttonite and cheralite crystallize together with Th-poor and La-rich monazite-(Ce) at the border of altered crystals. Nd/Sm and U/Pb ratios also changed during the hydrothermal stage. (authors) 13 refs.

  4. Signature splitting in 129Ce

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; WU Xiao-Guang; ZHU Li-Hua; LI Guang-Sheng; HE Chuang-Ye; LI Xue-Qin; PAN Bo; HAO Xin; LI Li-Hua; WANG Zhi-Min; LI Zhong-Yu; XU Qiang

    2009-01-01

    The high spin states of 129Ce have been populated via heavy-ion fusion evaporation reaction 96Mo (37C1, 1p3n) 129Ce. The γ-γ coincidence and intensity balance used to measure the B(M1; I→I-1)/B(E2; I→I-2) (the probability ratio of the dipole and quadrupole transition) in v7/2[523] rotational band of 129Ce. And the energy splitting (Δe') has been got through the experimental Routhians. The lifetimes and quadrupole moments Qt have been extracted from the lineshape analyses using DSAM. The deformation of the v7/2[523] rotational band of 129Ce was extracted from the Qt and moment of inertia JRR.

  5. Luminescence in LaBaB{sub 9}O{sub 16} prepared by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Sonekar, R.P.; Omanwar, S.K. [Department of Physics, Sant Gadgebaba Amravati University, Amravati (India); Moharil, S.V., E-mail: svmoharil@yahoo.co [Department of Physics, Rashtrasant Tukdoji Maharaj Nagpur University, Nagpur (India); Muthal, P.L.; Dhopte, S.M.; Kondawar, V.K. [National Environmental Engineering Research Institute, Nehru Marg, Nagpur (India)

    2009-06-15

    LaBaB{sub 9}O{sub 16} phosphors activated by various ions belonging to ns{sup 2}, 3d{sup n} and 4f{sup n} configurations were prepared by combustion synthesis. Phosphors' synthesis and luminescence spectra are reported. Most of the activators displayed intense characteristic emission. Pr{sup 3+}->Gd{sup 3+}, Ce{sup 3+}->Tb{sup 3+}, Ce{sup 3+}->Dy{sup 3+}, Ce{sup 3+}->Mn{sup 2+} and Bi{sup 3+}->Mn{sup 2+} energy transfers were also observed. In particular, Ce{sup 3+}->Tb{sup 3+} energy transfer leads to an efficient green emitting phosphor.

  6. New states in SmS

    International Nuclear Information System (INIS)

    Quasihydrostatic pressure resistivity experiments on a single crystal of SmS are reported up to 27.5 kbar. At low temperature, a regime change occurs at P approximately 20 kbar, between a ''quasiinsulating'' behavior (P 20 kbar). Striking similarities appear with TmSe and TmS cases. (author)

  7. Combined SM Higgs Limits at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Krumnack, N.

    2009-10-01

    We combine results from CDF and D{sup 0} on direct searches for a standard model (SM) Higgs boson (H) in p{bar p} collisions at the Fermilab Tevatron at {radical}s = 1.96 TeV. Compared to the previous Higgs Tevatron combination, more data and new channels WH {yields} {tau}{nu}b{bar b}, VH {yields} {tau}{tau}b{bar b}/jj{tau}{tau}, VH {yields} jjb{bar b}, t{bar t}H {yields} t{bar t}b{bar b} have been added. Most previously used channels have been reanalyzed to gain sensitivity. We use the latest parton distribution functions and gg {yields} H theoretical cross sections when comparing our limits to the SM predictions. With 2.0-3.6 fb{sup -1} of data analyzed at CDF, and 0.9-4.2 fb{sup -1} at D{sup 0}, the 95% C.L. upper limits on Higgs boson production are a factor of 2.5 (0.86) times the SM cross section for a Higgs boson mass of m{sub H} = 115 (165) GeV/c{sup 2}. Based on simulation, the corresponding median expected upper limits are 2.4 (1.1). The mass range excluded at 95% C.L. for a SM Higgs has been extended to 160 < m{sub H} < 170 GeV/c{sup 2}.

  8. SmAHTR-CTC Neutronic Design

    Energy Technology Data Exchange (ETDEWEB)

    Ilas, Dan [ORNL; Holcomb, David Eugene [ORNL; Gehin, Jess C [ORNL

    2014-01-01

    Building on prior experience for the 2010 initial SmAHTR neutronic design and on 2012 neutronic design for the advanced high temperature reactor (AHTR), this paper presents the main results of the neutronic design effort for the newly re-purposed SmAHTR-CTC reactor concept. The results are obtained based on full-core simulations performed with SCALE6.1. The dimensionality of the SmAHTR design space is reduced by using constraints originating in material fabricability, fuel licensing, molten salt chemistry, thermal-hydraulic and mechanical considerations. The new design represents in many regards a substantial improvement from the neutronic performance standpoint over the 2010 SmAHTR concept. Among other results, it is shown that fuel cycle length of over 2 years or discharged fuel burnup of 40GWd/MTHM are possible with a low, 8% fuel enrichment in a once-through fuel cycle, while 8-year once-through fuel cycle lengths are possible at higher fuel enrichments.

  9. Specific heat of REBaSrCu3O7 compounds (R=Nd, Sm, Dy, Er)

    International Nuclear Information System (INIS)

    Specific heat measurements have been performed on polycrystalline REBaSrCu3O7 (R=Nd, Sm, Dy, Er) in the temperature range from 0.3 to 3 K. Antiferromagnetic order is indicated by the λ-type peak in the specific heat at 1.2 and 0.6 K for Dy and Er compounds, respectively, whereas only a broad anomaly around 0.6 K is observed for Nd and Sm compounds. The specific heat data for Nd and Sm compounds are well fit with a Schottky-type anomaly with an energy splitting of 1.4 K, indicating the existence of an internal field of 2.42 T at the RE site. The magnetic singlet ground state of ErBaSrCu3O7 and DyBaSrCu3O7 is produ ced by exchange interactions of -0.05 and -0.035 T f.u./μB, respectively. (orig.)

  10. Effect of burnable poison addition on the thermo-mechanical properties of UO2-5wt5CeO2 pellets

    International Nuclear Information System (INIS)

    The microstructural characteristics and the thermo-mechanical properties of the pellets were evaluated and compared for UO2 and UO2-5wt%CeO2 pellets doped with burnable poisons (5wt% and 10wt% of Gd2O3, Sm2O3 and Dy2O3), sintered in reducing atmosphere for 4h. The sintered density and the grain size of UO2 and UO2-5wt%CeO2 pellets decreased by adding Gd2O3, Sm2O3 and Dy2O3 and the Vickers handness (Hv) of these pellets were found not affected with density and grain size variations. The fracture toughness (KIC) of the UO2 pellets increased with Gd2O3 and Dy2O3 adding and decreased with 10wt% Sm2O3 but that of UO2-5wt%CeO2 pellets were not changed. The fracture strength (of) of UO2 and UO2-5wt%CeO2 pellets were not affected by addition of burnable poison material and the critical thermal shock temperature difference (ΔTc) of the pellets increased for UO2 pellets doped with Gd2O3. Sm2O3 and Dy2O3 in the low temperature range (80 ∼ 200 .deg. C)

  11. Hydrothermal alteration of monazite-(Ce) from the Santa Maria de Itabira pegmatite district (Minas Gerais, Brazil)

    International Nuclear Information System (INIS)

    Monazite-(Ce) is found in granitic pegmatites in the Santa Maria de Itabira pegmatite district (Minas Gerais, Brazil). During the magmatic stage, monazite-(Ce) seems to have had higher contents of cheralite and buttonite in the solid solution. The Th content in primary monazite-(Ce) is high and characteristic for each pegmatite body. During the late stage (albitisation), the mean LREE content in the altered zone is slightly higher and Th content is very low. The accessory mineral assemblages changed; buttonite and cheralite crystallize together with Th-poor and La-rich monazite-(Ce) at the border of altered crystals. Nd/Sm and U/Pb ratios also changed during the hydrothermal stage. (authors)

  12. Preparation and quality control of {sup 153}Sm radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Swasono, R. Tamat; Widyastuti, W.; Purwadi, B.; Laksmi, I. [Radioisotope Production Center - BATAN, Jakarta (Indonesia)

    1998-10-01

    The paper summarizes the preparation and quality control of {sup 153}Sm-EDTMP and three {sup 153}Sm-radiosynovectomy agents. Natural and enriched Sm{sub 2}O{sub 3} (98.7% {sup 152}Sm) irradiated in RSG-GAS 30 MW reactor yielded pure and high specific activity {sup 153}Sm. Labeling of EDTMP with {sup 153}Sm was carried out by mixing {sup 153}SmCl{sub 3} solution of pH 4.0 to an EDTMP solution at room temperature then pH adjustment to 8. The {sup 153}Sm-EDTMP complex was separated from the free {sup 153}Sm{sup +3} on a Chelex 100 column. Radiochemical purity was determined by thin layer chromatography using Cellulose sheets and pyridine: ethanol: water (1: 2: 4) mixture as solvent. The {sup 153}Sm-EDTMP has been shown to be stable for two weeks. Three particulate preparations of {sup 153}Sm used for the irradiation of chronic synovitis have been studied. They are hydroxyapatite particles, human serum albumin microspheres and ferric hydroxide macroaggregates. The {sup 153}Sm-ferric hydroxide macroaggregates were prepared in a single step by coprecipitation of {sup 153}Sm in the formation of Fe(OH){sub 3}. Preparation of {sup 153}Sm-labelled hydroxyapatite particles and {sup 153}Sm-labelled albumin microspheres were carried out by {sup 153}Sm labelling of previously prepared particles. Radiolabelling efficiency were greater than 95% for hydroxyapatite particles and macroaggregates and was lower than 20% for albumin microspheres. The particle sizes were inspected using an optical microscope with a haemocytometer and micrometric ocular. (author)

  13. Intermediate valent metallic SmS and SmSe: a new puzzle

    International Nuclear Information System (INIS)

    It has been discovered that the R-T characteristic of so-called metallic SmS decreases with decreasing T at low temperatures for pressures exceeding approximately equal to kbar. This feature is reminiscent of a metal and in sharp contrast to the previously reported negative temperature coefficient at 10 and 20 kbar. The same fundamental change of the R-T dependence occurs in SmSe at approximately equal to 100 kbar. (author)

  14. (RE)BaCuO/Ag Composites: The Role of Silver in Bulk Materials and Joints

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We have investigated the phase equilibria in (RE)BaCuO/Ag systems, the influence of Ag on the processing of (RE)BaCuO/Ag composites and the resulting properties. YBaCuO/Ag composites have been grown by the modified melt crystallization process with YBa2Cu3O7, Y2O3, Pt and Ag2O in the precursor. The improved strength of the YBaCuO/Ag composites compared with the conventional YBaCuO bulk material permitted us to magnetize these materials to achieve trapped fields up to 16 T (at 24 K) in the gap of a mini-magnet. The investigation of the microstructure revealed a remarkable increase of the spacing between micro-cracks especially of those perpendicular to a/b-planes when 12 wt% Ag was added. In the case of SmBaCuO/Ag composites, Ag has a strong influence on processing and causes interactions between RE123 seeds and the sample. We show the growth of single-grain SmBaCuO/Ag composites in air and discuss the influence of post-annealing on increasing Tc and Jc. Furthermore, YBaCuO/Ag composites have been shown to be appropriate materials used as a solder to join large single grains to large arrays or to "repair" grain boundaries in arrays grown by a multiseeding technique.

  15. Kampen om det sibiriske smør

    DEFF Research Database (Denmark)

    Larsen, Inge Marie

    2001-01-01

    Afhandlingen følger opbygningen af og udviklingen i den vestsibiriske smørsektor og den internationale handel med sibirisk smør. Hvordan gik det til, at Rusland blev verdens næststørste smøreksportør? Indfaldsvinkelen er lokal sibirisk, national russisk og global, idet danske og engelske firmaers...

  16. Diagnostic significance of Schistosoma mansoni proteins Sm31 and Sm32 in human schistosomiasis in an endemic area in Egypt.

    Science.gov (United States)

    El-Sayed, L H; Ghoneim, H; Demian, S R; El-Sayed, M H; Tawfik, N M; Sakr, I; Abou-Basha, L M; Renganathan, E; Klinkert, M Q; Abou-Rawash, N

    1998-09-01

    We performed a series of ELISAs to evaluate the diagnostic significance of two Schistosoma mansoni proteins, Sm31 (cysteine proteinase, cathepsin B) and Sm32 (asparaginyl endopeptidase). Our study populations were chosen from two villages in an endemic area close to Alexandria. Using fusion proteins MS2-Sm31 and MS2-Sm32 as antigens, 70% and 78.9%, respectively, of patient sera from 134 parasitologically confirmed cases reacted positively. The percentage of seropositivity increased to 84.5% when parasite-derived proteins Sm31 and Sm32 were used. The serum levels of antibodies to these two proteins in recombinant or native forms do not correlate with intensity of infection and hence are detected even when egg counts are low, which makes proteins Sm31 and Sm32 useful antigens in the identification of S. mansoni infected cases, particularly in endemic areas in Egypt. PMID:9754667

  17. Evaluation of SmCo and SmCoN magnetron sputtering coatings for SOFC interconnect applications

    Science.gov (United States)

    Wu, Junwei; Li, Chengming; Johnson, Christopher; Liu, Xingbo

    Cobalt or cobalt containing coatings are promising for SOFC interconnect applications because of their high conductivity. We have investigated SmCo and SmCoN coatings deposited by magnetron sputtering from a SmCo (5% Sm) target on to Crofer 22 APU substrates. The composition, structure, surface morphology, and electrical conductivity of the coated substrates were characterized by SEM/EDX, XRD and ASR measurements. Addition of Sm enhances the oxidation resistance and the Cr retention capability of the coatings. The use of nitride as a precursor stabilizes Sm during oxidation of the films, thus inhibiting diffusion of Fe, resulting in a more compact coating and lowering ASR. The combined advantages of Sm addition to cobalt and the use of a nitride as a precursor, makes SmCoN coatings a promising new interconnect coating material.

  18. Leptonic B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Monorchio, Diego; /INFN, Naples /Naples U.

    2011-09-13

    The authors will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)} {nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be payed in order to perform a model independent analysis. A B-Factory provides an unique environment where to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  19. Leptonic B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Baracchini, Elisabetta; /Rome U. /INFN, Rome

    2011-11-10

    We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  20. Návrh vnitropodnikových směrnic pro vedení účetnictví v příspěvkové organizaci

    OpenAIRE

    Jedonová, Radana

    2009-01-01

    Bakalářská práce je zaměřená na problematiku vnitropodnikových směrnic pro vedení účetnictví příspěvkové organizace. V úvodní části je provedena analýza legislativních požadavků souvisejících s danou problematikou. Dále práce analyzuje již vypracované účetní směrnice organizace a poukazuje na jejich reálné nedostatky. Cílem práce je zefektivnění, aktualizace a zlepšení účetních směrnic. V závěrečné části bakalářské práce jsou vypracované nové účetní směrnice potřebné pro vnitřní řízení organi...

  1. High-Pressure Synthesis of Melilite-type Rare-Earth Nitridophosphates RE2P3N7 and a Ba2Cu[Si2O7]-type Polymorph.

    Science.gov (United States)

    Kloß, Simon D; Weidmann, Niels; Niklaus, Robin; Schnick, Wolfgang

    2016-09-19

    High-pressure metathesis was proposed to be a gateway to the elusive class of rare-earth nitridophosphates. With this method the first ternary compounds of this class with sum formula RE2P3N7 were prepared, a melilite-type with RE = Pr, Nd, Sm, Eu, Ho, Yb (Ho2P3N7: P4̅21m, a = 7.3589(2), c = 4.9986(2) Å, Z = 2) and a Ba2Cu[Si2O7] structure type with RE = La, Ce, Pr (Pr2P3N7: monoclinic, C2/c, a = 7.8006(3), b = 10.2221(3), c = 7.7798(3) Å, β = 111.299(1)°, Z = 4). The phase relation between the two structure types was prior unknown and is here evidenced by experimental data as well as density functional theory calculations performed for the Pr2P3N7 compounds. Adequate classification of both structures types with regard to Liebau nomenclature, vertex symbol, and point symbol is made. Additionally, the tiling patterns of the monolayered structures are deducted. We demonstrate that high-pressure metathesis offers a systematic access to rare-earth nitridophosphates with an atomic ratio of P/N between 1/2 and 1/4. PMID:27579899

  2. Performance of LaBaCo 2O 5+ δ-Ag with B 2O 3-Bi 2O 3-PbO frit composite cathodes for intermediate-temperature solid oxide fuel cells

    Science.gov (United States)

    Li, Ruifeng; Gao, Lei; Ge, Lin; Zheng, Yifeng; Zhou, Ming; Chen, Han; Guo, Lucun

    The composite cathodes LaBaCo 2O 5+ δ- x wt.% Ag (LBCO- xAg, x = 20, 30, 40, 50) were prepared by mechanical mixing method for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The experiment results indicated that the addition of a small amount of B 2O 3-Bi 2O 3-PbO (BBP) frit to LBCO- xAg can effectively improve the adhesion and strength of cathode membrane without damaging its porous structure. The BBP frit was proved effective for lowering the sintering temperature of LBCO- xAg to 900 °C. According to the electrochemical impedance spectroscopy and cathodic polarization analysis, the LBCO-30Ag exhibited the best performance and the optimal BBP frit content was 2.5 wt.%. For LBCO-30Ag with 2.5 wt.% BBP frit, the area-specific resistance based on Sm 0.2Ce 0.8O 1.9 (SDC) electrolyte decreased by about 57.6% at 700 °C, 60.5% at 750 °C and 75.9% at 800 °C compared to LBCO, and its cathodic overpotential was 10.7 mV at a current density of 0.2 A cm -2 at 700 °C, while the corresponding value for LBCO was 51.0 mV. The addition of Ag and BBP frit to LBCO had no significant effect on the thermal expansion.

  3. Layered perovskite oxide Y0.8Ca0.2BaCoFeO5+δas a novel cathode material for intermediate-temperature solid oxide fuel cells

    Institute of Scientific and Technical Information of China (English)

    余良浩; 陈永红; 顾庆文; 田冬; 卢肖永; 孟广耀; 林彬

    2015-01-01

    A layered perovskite oxide Y0.8Ca0.2BaCoFeO5+δ(YCBCF) was synthesized as a novel cathode material for intermedi-ate-temperature solid oxide fuel cells (IT-SOFCs) by citric acid-nitrates self-propagating combustion method. The phase and micro-structure of YCBCF were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The aver-age thermal expansion coefficient (TEC) of YCBCF was 14.6×10–6 K–1, which was close to other materials of SOFC at the range of RT–1000 ºC. An open-circuit potential of 0.75 V and a maximum output power density of 426 mW/cm2 were obtained at 650 ºC in a Sm0.2Ce0.8O1.9 (SDC)-based anode-supported SOFC by using humidified (~3%H2O) hydrogen as fuel and static air as oxidant. The results indicated that the YCBCF was a promising cathode candidate for IT-SOFCs.

  4. Sm-Nd and Rb-Sr isotopic data on the sanukitoid intrusions of the Karelia, Baltic Shield

    Science.gov (United States)

    Kovalenko, A. V.; Savatenkov, V. M.

    2003-04-01

    Sanukitoid intrusions from the Baltic Shield form post-tectonic differentiated intrusions 2.74-2.72 Ga old (Chekulaev, 1999, Lobach-Zhuchenko et al., 2000). They are represented by alkaline and calc-alkaline types which have high mg# (up to 0.6), strong LREE enrichment (Ce(N)=80-150, Yb(N)=4-7, Ce(N)/Yb(N)>20), high Sr, Ba (>1000 ppm), P2O5 (up to 1.5%) and Cr, Ni concentrations. Some intrusions contain rocks varying from ultramafite to quartz syenite. All sanukitoids are intruded by lamprophyre dykes having similar geochemical signatures. In this study we focus on the Karelian greenstone terrain within the Baltic Shield, in which sanukitoids are restricted to the younger western and central domains (2.7-2.9 Ga). Sanukitoids appear to be absent from the older Vodlozero domain (>3.0 Ga) in eastern Karelia (Lobach-Zhuchenko et al., 2000, Lobach-Zhuchenko et al., in press). About 70 Sm-Nd isotopic data on the sanukitoids of the Karelia were obtained. There is the regional distinction of the isotope composition of the rocks between the Central and West Karelian domains. The initial Epsilon Nd values and TDM range from +1.1 to +2.0 and 2.70-2.85 Ga accordingly in the youngest Central Karelian domain. The West Karelian intrusions yield an initial Epsilon Nd of -0.3- +0.7 and give the older TDM of about 2.82-2.92 Ga. It is to be noted that some intrusions of the Central Karelia domain, occurred closely to the ancient Vodlozero domain, also exhibit a similar range of initial Epsilon Nd and TDM to the intrusions of the West Karelia. There are narrow Nd isotopic compositional ranges within the individual intrusions. Rb-Sr isotopic system was studied in sanukitoids and lamprophyres of differentiated Panozero intrusion, Central Karelia. The initial 87Sr/86Sr isotope ratios range from 0.7000 to 0.7021 in these rocks indicating the derivation of these magmas from depleted mantle. Very low initial 87Sr/86Sr isotope ratios of the sanukitoids confirm the Nd isotopic characteristics

  5. SmS-Ga2S3 system

    International Nuclear Information System (INIS)

    The system SmS-Ga2S3 was studied by physico-chemical methods and diagrams of state drawn up. It was established that the compounds SmGa2S4 and SmGa4S7 were formed in the system. Orthorhombic (a=10.28, b=10.42, c=6.16 A, space group Bmbm) and monoclinic symetries are determined for SmGa2S4 and SmGa4S7 single crystals respectively

  6. A-site calcium-doped Pr1-xCaxBaCo2O5+δ double perovskites as cathodes for intermediate-temperature solid oxide fuel cells

    Science.gov (United States)

    Fu, Dawei; Jin, Fangjun; He, Tianmin

    2016-05-01

    The LnBaCo2O5+δ (Ln = rare earth) double perovskite cathodes possess superior electrochemical performance in intermediate-temperature solid oxide fuel cells (IT-SOFCs). However, high thermal expansion coefficients (TECs) and material costs are major challenges to their widespread applications. In this paper, a novel A-site Ca doping strategy that can suppress the spin-state transition of Co3+ is proposed to reduce the TECs and material costs of Pr1-xCaxBaCo2O5+δ (x = 0.1-0.4; PCBCO). Substitution of Ca for Pr effectively reduces the TEC from 22.2 × 10-6 K-1 at x = 0.1 to 19.1 × 10-6 K-1 at x = 0.3 between 100 and 800 °C. PCBCO exhibits good chemical compatibility with the Sm0.2Ce0.8O1.9 (SDC) electrolyte. The area-specific resistances of PCBCO cathodes with x = 0.1, 0.2, and 0.3 are 0.081, 0.082, and 0.089 Ω cm2, respectively, at 700 °C on the SDC electrolyte. The maximum power densities of a single cell on a 0.3 mm-thick SDC electrolyte reach 646.5, 636.8, and 620.6 mW cm-2 at 800 °C for cathodes with x = 0.1, 0.2, and 0.3, respectively. The PCBCO double perovskites exhibit excellent chemical compatibility and electrochemical performance while reducing the TECs and material costs; thus, these double perovskites are promising cathode materials for applications in IT-SOFCs.

  7. Transport properties of golden SmS

    International Nuclear Information System (INIS)

    We report electrical resistivity and Hall effect measurements on golden SmS up to a pressure of P∼26kbar. The Hall coefficient at a low temperature shows a drastic decrease above about 13 kbar as a function of P, and a change in sign at a critical pressure Pc2 above which an antiferromagnetically ordered phase appears. We construct a P-T phase diagram from the transport properties together with previously reported results of the ac magnetic susceptibility

  8. Instability of SmS under pressure

    International Nuclear Information System (INIS)

    It is suggested that electron-phonon (EP) interaction is a suitable mechanism to explain the instability of the semiconducting phase in SmS under pressure. The f reversible d and d reversible d scattering processes due to EP interaction avoid the introduction of negative renormalized f-d hybridization assumed by some other models as the source of the first order instability. Moreover this instability is shown as occuring for a non-zero energy gap. (orig.)

  9. The SM-200 step motor control device

    International Nuclear Information System (INIS)

    One of the main nodes of the stand for testing and modeling solenoid coils, which define the focus of the beam of charged particles in the accelerator LUE-200 (IREN), is a device for positioning Hall sensors (HS). The mechanism of movement of the platform where HS are installed is activated by the step motor. This paper describes the control device of the step motor SM-200

  10. X(5 Symmetry to 152Sm

    Directory of Open Access Journals (Sweden)

    Eid S. A.

    2016-07-01

    Full Text Available The excited positive and negative parity states, potential energy surfaces, V ( ; , electromagnetic transition probabilities, B ( E 1, B ( E 2, electric monopole strength X ( E 0 = E 2 and staggering e ect, I = 1, were calculated successfully using the inter- acting boson approximation model IBA -1. The calculated values are compared to the available experimental data and show reasonable agreement. The energy ratios and contour plot of the potential energy surfaces show that 152 Sm is an X (5 candidate.

  11. Výpočet směrových charakteristik antén v programu Comsol Multiphysics

    OpenAIRE

    Ryšánek, Martin

    2008-01-01

    Bakalářská práce na téma Výpočet směrových charakteristik antén v programu Comsol Multiphysics. V první části jsou představeny základní teoretické pojmy. Druhá část je věnována analýze několika druhů antén programem COMSOL Multiphysics a výpočtu jejich směrových charakteristik a vstupních impedancí. V třetí části jsou souhrnně zpracovány změřená a vypočtená data. The individual project – Computing directivity patterns in Comsol Multiphysics. In the first part, the theoretical background fo...

  12. Návrh kompozitového směrového kormidla pro letoun L 410 NG

    OpenAIRE

    Sokol, Filip

    2015-01-01

    Tato diplomová práce se zabývá návrhem kompozitní konstrukce směrového kormidla letounu L410 NG vycházející ze současné duralově-plátnové konstrukce. Podle předpisu FAR 23 a jeho oběžníků je navržen postup certifikace kompozitní primární konstrukce letounu. Je navržena konstrukce nového směrového kormidla a z vybraných materiálů proveden návrh skladby kompozitních materiálů. Programem MSC Patran je z této konstrukce vytvořen MKP model a pomocí softwarů Compost a Nastran provedena pevnostní ko...

  13. The Naturalness of the Fourth SM Family

    CERN Document Server

    Sultansoy, S

    2009-01-01

    The necessity of the fourth family follows from the SM basics. According to flavor democracy the Dirac masses of the fourth SM family fermions are almost equal with preferable value 450 GeV, which corresponds to common (for all fundamental fermions) Yukawa coupling equal to SU(2) gauge coupling gW. In principle, one expect u4 a little bit lighter than d4, while nu4 could be essentially lighter than l4 due to Majorana mass terms for right-handed components of neutrinos. Obviously, the fourth family quarks will be copiously produced at the LHC. However, the first indication of the fourth SM family may be provided by early Higgs boson observation due to almost an order enhancement of the gluon fusion to Higgs cross-section. For the same reason the Tevatron still has a chance to observe the Higgs boson before the LHC. Concerning the fourth family leptons, in general, best place will be NLC/CLIC. However, for some mass regions and MNS matrix elements double discovery of both the nu4 and H could be possible at the ...

  14. Lifetime measurement for the 21+ state in 140Sm and the onset of collectivity in neutron-deficient Sm isotopes

    Science.gov (United States)

    Bello Garrote, F. L.; Görgen, A.; Mierzejewski, J.; Mihai, C.; Delaroche, J. P.; Girod, M.; Libert, J.; Sahin, E.; Srebrny, J.; Abraham, T.; Eriksen, T. K.; Giacoppo, F.; Hagen, T. W.; Kisielinski, M.; Klintefjord, M.; Komorowska, M.; Kowalczyk, M.; Larsen, A. C.; Marchlewski, T.; Mitu, I. O.; Pascu, S.; Siem, S.; Stolarz, A.; Tornyi, T. G.

    2015-08-01

    Background: The chain of Sm isotopes exhibits a wide range of nuclear shapes and collective behavior. While the onset of deformation for N >82 has been well studied both experimentally and theoretically, fundamental data is lacking for some Sm isotopes with N Weisskopf units. The theoretical calculations are in very good agreement with the experimental result. Conclusions: The B (E 2 ;21+→01+) value for 140Sm fits smoothly into the systematic trend for the chain of Sm isotopes. The new beyond-mean field calculations are able to correctly describe the onset of collectivity in the Sm isotopes below the N =82 shell closure for the first time.

  15. High-perfomance Ce-doped multicomponent garnet single crystalline film scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Zorenko, Yu.; Gorbenko, V.; Zorenko, T. [Institute of Physics, Kazimierz Wielki, University in Bydgoszcz, Powstancow, Wielkopolskich str., 2, 85090, Bydgoszcz (Poland); Department of Electronics of Ivan Franko, National University of Lviv, Gen. Tarnavskiy str. 17, 79017, Lviv (Ukraine); Sidletskiy, O. [Institute for Single Crystals, National Academy of Sciences of Ukraine, Lenina str., 60, 61001, Kharkiv (Ukraine); Fedorov, A. [SSI Institute for Single Crystals, National Academy of Sciences of Ukraine, Lenina str., 60, 61178, Kharkiv (Ukraine); Bilski, P.; Twardak, A. [Institute of Nuclear Physic, Polish Academy of Sciences, Radzikowskiego str., 176, 31-342, Krakow (Poland)

    2015-08-15

    We report for the first time the optimized content and excellent scintillation properties of single crystalline film (SCF) scintillators of multicomponent Gd{sub 3-x}Lu{sub x} Al{sub 5-y}Ga{sub y} O{sub 12}:Ce garnet compounds grown by liquid phase epitaxy (LPE) method. The Gd{sub 1.5}Lu{sub 1.5}Al{sub 2.75}Ga{sub 2.25}O{sub 12}:Ce and Gd{sub 3}Al{sub 2.75-2}Ga{sub 2.25-3}O{sub 12}:Ce SCF show the light yield (LY) comparable with that of high-quality bulk crystal analogues of these garnets but faster scintillation decay and very low thermoluminescence in the above room temperature range. To our knowledge, these SCF possess the highest LY values ever obtained in LPE grown garnet SCF scintillators exceeding by at least 1.5-1.6 times the values previously reported for SCF scintillators. Left figure: image of Gd{sub 1.5}Lu{sub 1.5}Al{sub 2.75}Ga{sub 2.25}O{sub 12}:Ce (PbO) (inset, left) and Gd{sub 3}Al{sub 2.35}Ga{sub 2.65}O{sub 12}:Ce (BaO) (inset, right) SCF scintillators, grown by LPE method onto Gd{sub 3}Al{sub 2.5}Ga{sub 2.5}O{sub 12} (GAGG) substrate; in the middle, green-yellow light emitting by Gd{sub 1.5}Lu{sub 1.5}Al{sub 2.75}Ga{sub 2.25}O{sub 12}:Ce (BaO) SCF under 350 nm laser illumination. Right figure: XRD pattern of (1200) planes of the Gd{sub 1.5}Lu{sub 1.5}Al{sub 2.75}Ga{sub 2.25}O{sub 12}:Ce (PbO) (black) and Gd{sub 3}Al{sub 2.75}Ga{sub 2.25}O{sub 12}:Ce (BaO) (red) SCFs, grown onto GAGG substrates. The film/substrate lattice misfit is -0.73% and -0.3%, respectively. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Characterization and activity of alkaline earth metals loaded CeO{sub 2}–MO{sub x} (M = Mn, Fe) mixed oxides in catalytic reduction of NO

    Energy Technology Data Exchange (ETDEWEB)

    Mousavi, Seyed Mahdi [Department of Applied Chemistry and Chemical Engineering, Faculty of Chemistry, University of Tabriz, 5166616471 Tabriz (Iran, Islamic Republic of); Niaei, Aligholi, E-mail: niaei@yahoo.com [Department of Applied Chemistry and Chemical Engineering, Faculty of Chemistry, University of Tabriz, 5166616471 Tabriz (Iran, Islamic Republic of); Illán Gómez, María José [Carbon Materials and Environment Research Group, Department of Inorganic Chemistry, Faculty of Science, Universidad de Alicante, Alicante (Spain); Salari, Dariush; Nakhostin Panahi, Parvaneh [Department of Applied Chemistry and Chemical Engineering, Faculty of Chemistry, University of Tabriz, 5166616471 Tabriz (Iran, Islamic Republic of); Abaladejo-Fuentes, Vicente [Carbon Materials and Environment Research Group, Department of Inorganic Chemistry, Faculty of Science, Universidad de Alicante, Alicante (Spain)

    2014-02-14

    Nanocrystalline CeO{sub 2}–MO{sub x} mixed oxides (M = Mn, Fe) with different M/(M + Ce) molar ratio are prepared by sol–gel combustion method. X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Temperature Programmed Reduction with H{sub 2} (H{sub 2}-TPR) and N{sub 2}-adsorption (BET) analyses are conducted to characterize the physical–chemical properties of the catalysts. The activity of catalysts for reduction of NOx with ammonia has been evaluated. The CeO{sub 2}–MnO{sub x} catalysts showed better low temperature activity than CeO{sub 2}–FeO{sub x}. The superior activity of CeO{sub 2}–MnO{sub x} with Mn/(Mn + Ce) molar ratio of 0.25 respect to other catalysts (with 83% NO conversion and 68% N{sub 2} yield at 200 °C) is associated to nanocrystalline structure, reducibility at low temperature and synergistic effect between Ce and Mn that are observed by XRD, TEM and H{sub 2}-TPR. The CeO{sub 2}–FeO{sub x} catalysts were found to be active at high temperature, being Ce–Fe the best catalyst yielded 82% NO conversion at 300 °C. The effect of alkaline earth metals (Ca, Mg, Sr and Ba) loading on the structure and catalytic activity of cerium mixed oxides are also investigated. Loading of Ba enhanced the NO reduction activity of mixed oxides due to the increase of number of basic sites. Highest performance with 91% NO conversion and 80% N{sub 2} yield attained over CeO{sub 2}–MnO{sub x} (0.25)-Ba (7%) catalyst at 200 °C. - Highlights: • CeO{sub 2}–MO{sub x} mixed oxides (M = Mn, Fe) were synthesized by sol–gel combustion method. • The activity of mixed oxides is evaluated in catalytic reduction of NO with NH{sub 3}. • The CeO{sub 2}–MnO{sub x} showed better activity than CeO{sub 2}–FeO{sub x} due to better redox properties. • Ba loading enhanced the activity due to the increase of number of basic sites. • 91% NO conversion and 80% N{sub 2} yield attained over 7%Ba–Ce{sub 0.75}Mn{sub 0.25}O{sub 2} at 200 °C.

  17. Effect of oxygen partial pressure on the morphology and properties of Ce doped YBCO films fabricated by a MOCVD process

    International Nuclear Information System (INIS)

    Rare-earth (RE) (e.g. Sm, Dy, Ce, etc.) doping has been widely investigated to improve critical current density (Jc) of YBa2Cu3O7-X (YBCO) coated conductors (CC). Oxygen partial pressure is known to be a key parameter in terms of affecting the Jc of YBCO films. In this work, the effect of oxygen partial pressure on the microstructure and Jc of a Ce doped YBCO film was examined. Ce doped YBCO films were deposited on (1 0 0) SrTiO3 (STO) single crystal substrates at oxygen partial pressures of 2.5, 5.0, and 10.0 Torr using a metal organic chemical vapor deposition (MOCVD) method. Due to the enhanced migration of surface adatoms under reduced oxygen partial pressure, a 1 wt% Ce doped YBCO film had a stoichiometric, dense surface. In addition, the zero-field Jc (at 77 K) of the 1 wt% Ce doped YBCO film deposited at reduced oxygen partial pressure was increased. Irrespective of the amount of Ce, the Ce doped YBCO film showed an increased zero-field Jc (at 77 K) under reduced oxygen partial pressure.

  18. Problematika zvyšování podílu R - materiálu v asfaltových směsích

    OpenAIRE

    Urbanec, Luboš

    2013-01-01

    Předmětem této diplomové práce je problematika asfaltových směsí se zvyšujícím se podílem R-materiálu. V teoretické části práce jsou definovány pojmy recyklace a R-materiál a popsány druhy recyklace. Praktická část se věnuje výrobě a zkoušení asfaltových směsí s různým obsahem R-materiálu. Navrhovaná asfaltová směs je asfaltový beton pro podkladní vrstvy ACP22+. Obsah R-materiálu ve směsích je 0%, 30%, 50% a 70%. Jako speciální přísada pro změkčení asfaltu z R-materiálu se používá přísada STO...

  19. Bäuerliche Selbstorganisation, bäuerliches Erfahrungswissen und bäuerlicher Widerstand in Belarus

    OpenAIRE

    Konrad Berghuber

    2015-01-01

    Ausgehend vom Commonsdiskurs und von anarchistischen Vorstellungen über bäuerliches Leben als Vorbild für eine solidarische Gesellschaft untersucht der vorliegende Artikel bäuerliche Selbstorganisation, bäuerliches Erfahrungswissen und bäuerliche Kämpfe gegen herrschende Schichten auf dem Gebiet von Belarus seit der Abschaffung der Leibeigenschaft 1861. Anhaltspunkte bäuerlicher Selbstorganisation stellen die Obschtschina sowie Kooperationen bei der Produktion und der Maschinennutzung...

  20. Fast timing study of a CeBr3 crystal: Time resolution below 120 ps at 60Co energies

    International Nuclear Information System (INIS)

    We report on the time response of a novel inorganic scintillator, CeBr3. The measurements were performed using a cylindrical crystal of 1-in. in height and 1-in. in diameter at 22Na and 60Co photon energies. The time response was measured against a fast reference BaF2 detector. Hamamatsu R9779 and Photonis XP20D0 fast photomultipliers (PMTs) were used. The PMT bias voltages and Constant Fraction Discriminator settings were optimized with respect to the timing resolution. The Full Width at Half Maximum (FWHM) time resolution for an individual CeBr3 crystal coupled to Hamamatsu PMT is found here to be as low as 119 ps at 60Co energies, which is comparable to the resolution of 107 ps reported for LaBr3(Ce). For 511 keV photons the measured FWHM time resolution for CeBr3 coupled to the Hamamatsu PMT is 164 ps.

  1. Band-overlap metallization of BaS, BaSe and BaTe

    Science.gov (United States)

    Carlsson, A. E.; Wilkins, J. W.

    1983-01-01

    The insulator-metal transition volumes for BaS, BaSe, and BaTe are calculated for the first time, using the self-consistent augmented spherical wave technique. The metallized transition volumes are smaller than those corresponding to the NaCl yields CsCl structural transitions, but, 10 to 15% larger than those obtained by the Herzfeld dielectric theory. The calculated equilibrium energy gaps in the NaCl structure underestimate the measured ones by 50 to 60%.

  2. Temperature and host dependence of the transition interference between f–f and f–d transitions of Sm{sup 2+} in matlockites

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Prodipta, E-mail: prodipta.pal08@gmail.com [Département de Chimie Physique,Sciences II, Université de Genève, 30, Quai Ernest-Ansermet, CH-1211 Genève 4 (Switzerland); Hagemann, Hans; Bill, Hans [Département de Chimie Physique,Sciences II, Université de Genève, 30, Quai Ernest-Ansermet, CH-1211 Genève 4 (Switzerland); Zhang, Jiahua [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033 (China)

    2015-05-15

    The absorption spectra of Sm{sup 2+} doped in MFX (M=Sr, Ba; X=Cl, Br) crystals were studied within the range of 20,000–35,000 cm{sup −1} as a function of temperature and host. The absorption bands observed were described with a simple model developed by Wood and Kaiser using group theory. The temperature and host dependence on the {sup 7}F{sub 0}→{sup 5}D{sub 3} Fano resonance lines were investigated. BaFCl:Sm{sup 2+} system showed a “normal” {sup 7}F{sub 0}→{sup 5}D{sub 3} transition at 4 K in spite of similar crystal structure and absorption profile with other MFX hosts. New Fano resonances were observed in the absorption spectra at higher energies (23,000–25,000 cm{sup −1}) for all MFX:Sm{sup 2+} systems at 4 K which persist up to room temperature. Preliminary energy level calculation showed that these resonance lines involve the interaction between higher excited {sup 5}L{sub J} states of 4f{sup 6} configuration and 4f{sup 5}5d{sup 1} configuration. - Highlights: • The absorption spectra of Sm{sup 2+} doped in MFX (M=Sr, Ba; X=Cl, Br) crystals within the range of as a function of temperature and host. • The absorption bands described with a simple model developed by Wood and Kaiser using group theory. • BaFCl:Sm{sup 2+} system showed a “normal” {sup 7}F{sub 0}→{sup 5}D{sub 3} transition at 4 K in spite of similar crystal structure and absorption profile with other MFX hosts. • New Fano resonances observed in the absorption spectra at higher energies (23,000–25,000 cm{sup −1}) for all MFX:Sm{sup 2+} systems at 4 K which persist up to room temperature.

  3. Synthesis and characterization of (Ba,Yb doped ceria nanopowders

    Directory of Open Access Journals (Sweden)

    Branko Matović

    2011-06-01

    Full Text Available Nanometric size (Ba, Yb doped ceria powders with fluorite-type structure were obtained by applying selfpropagating room temperature methods. Tailored composition was: Ce0.95−xBa0.05YbxO2−δ with fixed amount of Ba − 0.05 and varying Yb content “x” from 0.05 to 0.2. Powder properties such as crystallite and particle size and lattice parameters have been studied. Röntgen diffraction analyses (XRD were used to characterize the samples at room temperature. Also, high temperature treatment (up to 1550°C was used to follow stability of solid solutions. The mean diameters of the nanocrystals are determined from the full width at half maxima (FWHM of the XRD peaks. It was found that average diameter of crystallites is less than 3 nm. WilliamsonHall plots were used to separate the effect of the size and strain in the nanocrystals.

  4. Sm{sup 3+}-doped alkaline earth borate glasses as UV→visible photon conversion layer for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shen, L.F. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Chen, B.J.; Pun, E.Y.B. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Lin, H., E-mail: lhai8686@yahoo.com [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2015-04-15

    Intense multi-peak red fluorescence emissions of Sm{sup 3+} are exhibited in alkaline-earth borate (LKZBSB) glasses under UV radiation. The spontaneous emission probabilities A{sub rad} corresponding to the {sup 4}G{sub 5/2}→{sup 6}H{sub J} (J=5/2, 7/2, 9/2 and 11/2) transitions are derived to be 24.74, 129.72, 117.03 and 32.23 s{sup −1}, respectively, and the relevant stimulated emission cross-sections σ{sub em} are 0.77×10{sup −22}, 4.46×10{sup −22}, 5.05×10{sup −22} and 1.38×10{sup −22} cm{sup 2}, confirming the effectiveness of red luminescence in Sm{sup 3+}-doped LKZBSB glasses. Quantitative characterization through the evaluation of absolute spectral parameters reveals that the quantum yield of Sm{sup 3+}-doped LKZBSB glasses is as high as 13.29%. Furthermore, with the introduction of Ce{sup 3+}, the effective excitation wavelength range and the emission intensity of Sm{sup 3+} in LKZBSB glasses are remarkably expanded and improved by a maximum sensitization factor of 9.02 in the UVB region. These results demonstrate that the present glass system has promising potential as an efficient UV→visible photon conversion layer for the enhancement of solar cell efficiency, including appealing applications in outer space. - Highlights: • Intense multi-peak red fluorescence emissions of Sm{sup 3+} are exhibited under UV radiation. • Effectiveness of red luminescence is confirmed by stimulated emission cross-sections. • Quantum yield of Sm{sup 3+}-doped LKZBSB glasses is 13.29% by quantitative characterization. • Effective excitation wavelength range and emission intensity are improved with Ce{sup 3+} doping. • Alkaline-earth borate glass has potential as solar cell UV→Vis photon conversion layer.

  5. Thermal properties of perovskite RCeO{sub 3} (R = Ba, Sr)

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Aarti, E-mail: aarti.phy@gmail.com [Department of Physics, Barkatullah University, Bhopal 462026 (India); Parey, Vanshree; Thakur, Rasna [Department of Physics, Barkatullah University, Bhopal 462026 (India); Srivastava, Archana [Department of Physics, Sri Sathya Sai College for women, Bhopal 462024 (India); Gaur, N.K. [Department of Physics, Barkatullah University, Bhopal 462026 (India)

    2015-08-20

    Highlights: • (Ba,Sr)CeO{sub 3} are high temperature protonic conductor materials. • This makes their thermal properties very interesting. • MRIM has successfully predicted the thermodynamic properties. • The computed results are in good agreement with the available experimental data. • Present results will serve as guide to experimental workers in future. - Abstract: We have investigated the bulk modulus and thermal properties of proton conducting perovskite RCeO{sub 3} (R = Ba, Sr) for the first time by incorporating the effect of lattice distortion in modified rigid ion models (MRIM). The computed bulk modulus, specific heat, thermal expansion coefficient and other thermal properties of BaCeO{sub 3} and SrCeO{sub 3} reproduce well with the available experimental data. In addition the cohesive energy (ϕ), molecular force constant (f), reststrahlen frequency (ν), Debye temperature (θ{sub D}) and Gruneisen parameter (γ) are also reported and discussed. The specific heat results can further be improved by taking into account the spin and the orbital ordering contribution in the specific heat formulae.

  6. Orange and reddish-orange light emitting phosphors: Sm3+ and Sm3+/Eu3+ doped zinc phosphate glasses

    International Nuclear Information System (INIS)

    A spectroscopy study of Sm3+ and Sm3+/Eu3+ doped zinc phosphate glasses is performed through photoluminescence spectra and decay time profile measurements. Under Sm3+ excitation at 344 nm, the Sm3+ singly doped glass shows an orange global emission with x=0.579 and y=0.414 CIE1931 chromaticity coordinates, whereas the Sm3+/Eu3+ co-doped sample exhibits orange overall emissions (x=0.581 and y=0.398, and x=0.595 and y=0.387) and reddish-orange overall emission (x=0.634 and y=0.355) upon excitations at 344, 360 and 393 nm, respectively. Such luminescence from the co-doped sample is originated by the simultaneous emission of Sm3+ and Eu3+. Under Sm3+ excitation at 344 and 360 nm, the Eu3+ emission is sensitized and enhanced by Sm3+ through a non-radiative energy transfer process. The non-radiative nature was inferred from the shortening of the Sm3+ lifetime observed in the Sm3+/Eu3+ co-doped sample. An analysis of the Sm3+ emission decay time profiles using the Inokuti–Hirayama model suggests that an electric quadrupole–quadrupole interaction into Sm–Eu clusters might dominate the energy transfer process, with an efficiency of 0.17. - Highlights: • Zinc phosphate glasses are optically activated with Sm3+/Eu3+ (ZPOSmEu). • Non-radiative energy transfer Sm3+→Eu3+ takes place in ZPOSmEu. • ZPOSmEu overall emission can be modulated with the excitation wavelength. • ZPOSmEu might be useful as orange/reddish-orange phosphor for UV-white LEDs

  7. Flux pinning properties of TFA-MOD (Y,Gd)Ba2Cu3Ox tapes with BaZrO3 nanoparticles

    International Nuclear Information System (INIS)

    A high critical current density Jc with a nearly isotropic angular dependence at 77.3 K was recently obtained by the introduction of nanoparticles to (Y,RE)Ba2Cu3Oy (RE123, RE = Sm, Gd)-coated conductors prepared by trifluoroacetate metal-organic deposition (TFA-MOD). The flux pinning properties were evaluated on the basis of detailed measurements of the upper critical field, the irreversibility field and the critical current density of the TFA-MOD RE123-coated conductor. We found that strong random pinning by the BaZrO3 nanoparticles and weak c-axis correlated pinning by twin boundaries functioned cooperatively in nanoparticles introduced to (Y, Gd)123-coated conductors prepared by TFA-MOD. The coexistence of two different pinning centers played an important role in the nearly isotropic angular dependence of Jc.

  8. ELECTROCHEMICAL BEHAVIOR AND KINETICS OF THE INTERVALENCE CHARGE TRANSFER FOR THE SM(III)/SM(II) REDOX COUPLE IN LiF-CaF2 MELT

    OpenAIRE

    Stulov Yuriy Vyacheslavovich; Korenko Michal; Kubikova Blanca; Kuznetsov Sergey Aleksandrovich

    2015-01-01

    This article is focused on the electrochemical investigation (cyclic voltammetry) of the redox couple Sm(III)/Sm(II) in an eutectic LiF–CaF2 melt containing SmF3. The first step of reduction for Sm(III) ions, involving one electron exchange in soluble/soluble Sm(III)/Sm(II) system, was found on a tungsten electrode. The study of the Sm(II)/Sm(0) electrode reaction was not feasible, since it’s the redox potential is in the same range of the solvent decomposition. The first step was fo...

  9. Phase equilibria of Ba-R-Cu-O for coated conductor applications (R lanthanides and Y)

    Energy Technology Data Exchange (ETDEWEB)

    Wong-Ng, W.; Cook, L.P.; Levin, I.; Suh, J.; Feenstra, R.; Haugan, T.; Barnes, P

    2004-08-01

    Phase diagrams of the Ba{sub 2}RCu{sub 3}O{sub 6+x}(R = Nd, Sm, Gd, Y, and Er) superconductors, prepared under 100 Pa O{sub 2} at 810 deg. C, reflect the trend of the lanthanide contraction. The single-phase regions of Ba{sub 2-x}(Nd{sub 1+x-y}R{sup '}{sub y})Cu{sub 3}O{sub 6+z} for R{sup '} = Gd, Y and Yb, and of Ba{sub 2-x}(R{sub 1+x-y}Y{sub y})Cu{sub 3}O{sub 6+z} for R = Eu and Gd were determined. Using these data, both flux-pinning and melting properties can be tailored and optimized. The presence of a low temperature melt during formation of the Ba{sub 2}YCu{sub 3}O{sub 6+x} phase from barium fluoride amorphous precursor films is deemed important for producing quality tapes, and hence for rapid advancement of second-generation RABiTS/IBAD coated conductor technology. Our search for low melting liquid has focused on compositional vectors within the Ba, Y, Cu-O, F reciprocal system.

  10. Dislocations in SmS single crystals

    International Nuclear Information System (INIS)

    Single crystals of SmS with NaCl structure are grown by zone melting in a sealed molybdenum tube. Dislocations introduced during cleaving the crystal are investigated by transmission electron microscopy. The dislocations have Burgers vector of 1/2 and their glide plane is (11-bar0), i.e. the slip system is (11-bar0) as in alkali-halide NaCl-type crystals. The slip seems to be governed by the Peierls mechanism for the screw dislocation. (author)

  11. Smørrebrød

    DEFF Research Database (Denmark)

    Fisker, Anna Marie; Jørgensen, René Langdahl

    This little book is dedicated to students and teachers at the Gastronomic University of Bra, whom in the early summer of 2012 are visiting Center for Food Science, Design & Experience at Aalborg University, where a number of courses in Food+Design is held. In this little book we have asked outsta...... outstanding Danish personalities, who is occupied with “smørrebrød”, to give a peek into this world of Danish food culture. And with a little help from chef Klausen in Hune we have chosen to serve and conceptualize a “Stjerneskud”....

  12. The influence of impurity on the critical thickness of the CeO2 buffer layer for coated conductors

    Institute of Scientific and Technical Information of China (English)

    PAN Min; HUANG Zheng; MA HuanFeng; QIANG WeiRong; WEI LianFu; WANG Long; ZHAO Yong

    2009-01-01

    The lattice parameters, band structure, density of state and elastic constant of RE-doped CeO2 (RE=Sm, Gd, Dy), the buffer material for coated HTS conductors, are calculated using the plane-wave method with paeudopotentials based on the density functional theory (DFT) of first-principle. The rule and mechanism of the effect of rare earth impurity on the critical thickness of the CeO2 buffer layer are in-vestigated. It is found that, in the range of the calculation, the changes of the lattice volume Ⅴ and elastic constant E* of CeO2 with the impurity are mainly determined by the increased electrons △ne of the system. The relationship of the elastic constant E* and increased electrons △ne is established. It is indicated that the critical thickness of the CeO2 single buffer layer doped with Sm, Gd, and Dy may be enhanced by 22%, 43% and 33%, respectively.

  13. Vliv stabilizátorů a dalších složek na výslednou kvalitu sypkých směsí pro výrobu zmrzlin

    OpenAIRE

    Sládková, Veronika

    2011-01-01

    Předložená diplomová práce byla zaměřena na studium vlivu stabilizátorů a dalších složek na výslednou kvalitu sypkých směsí pro výrobu zmrzlin. Diplomová práce byla řešena ve spolupráci s výrobcem směsí Frujo, a.s., Tvrdonice, a to za účelem výběru vhodného stabilizátoru pozitivně ovlivňujícího výslednou kvalitu výrobku. V rámci experimentální práce bylo analyzováno šest stabilizačních směsí, tři kompletní sypké směsi pro výrobu točených zmrzlin a jednotlivé suroviny pro výrobu těchto sypkých...

  14. CHRiSM: CHance Rules induce Statistical Models

    OpenAIRE

    Sneyers, Jon; Meert, Wannes; Vennekens, Joost

    2009-01-01

    A new probabilistic-logic formalism, called CHRiSM, is introduced. CHRiSM is based on a combination of CHR and PRISM. It can be used for high-level rapid prototyping of complex statistical models by means of chance rules. The underlying PRISM system can then be used for several probabilistic inference tasks, including parameter learning. We describe a source-to-source transformation from CHRiSM rules to PRISM, via CHR(PRISM). Finally we discuss the relation between CHRiSM and probab...

  15. Disequilibrium effects in metal speciation by capillary electrophoresis inductively coupled plasma mass spectrometry (CE-ICP-MS); theory, simulations and experiments.

    Science.gov (United States)

    Sonke, Jeroen E; Salters, Vincent J M

    2004-08-01

    A theoretical-experimental approach to evaluate disequilibrium effects in capillary electrophoresis inductively coupled plasma mass spectrometry (CE-ICP-MS) is presented. Electrophoresis requires metal ligand (ML) complexes to be stable on the time scale of separation and detection. By expressing ML complex stability in terms of half-life during a CE separation, an evaluation of separation artifacts can be made. Kinetically slow metals like Cr, Al or Fe form complexes that are stable on the time scale of electrophoretic separations. Kinetically fast metals, like Pb, Hg, Cu, Cd and REE, however tend to form labile complexes which unless complexed by strong chelators will dissociate during CE separations. A reactive transport simulation model of CE separations involving ML complexes allows a more detailed prediction of disequilibrium bias and identifies kinetically limited from mobility-limited types of dissociation. Complementary experimental results are given for kinetic and equilibrium binding experiments of Sm with humic acid. The equilibrium logK for Sm-Leonardite humic acid (HA) binding at pH 7 and 0.01 mol L(-1) ionic strength was determined to be 13.04. Kinetic rates of formation and dissociation for SmHA were 5.9 10(8) and 5.3 10(-5) mol s(-1). PMID:15284917

  16. Invisible KL decays in the SM extensions

    Science.gov (United States)

    Gninenko, S. N.; Krasnikov, N. V.

    2016-07-01

    In the Standard Model (SM), the branching ratio for the decay KL → νν¯ is helicity suppressed and predicted to be very small ≤ O(10‑17). We consider two natural extensions of the SM as the two-Higgs-doublet model (2HDM) and the neutrino minimal Standard Model (νMSM) with additional singlet scalar, whose main feature is that they can lead to an enhanced Br(KL → invisible). In the 2HDM, the smallness of the neutrino mass is explained due to the smallness of the second Higgs doublet vacuum expectation value. Moreover, the νMSM extension with additional singlet field can explain the (g ‑ 2)μ anomaly. The considered models demonstrate that the KL → invisible decay is a clean probe of new physics scale well above 100 TeV, that is complementary to rare K → π + invisible decay, and provide a strong motivation for its sensitive search in a near future low-energy experiment.

  17. The SmS-Ga2S3 section of the ternary Sm-Ga-S system

    International Nuclear Information System (INIS)

    The SmS-Ga2S3 section of the Sm-Ga-S system is investigated by differential-thermal, XPA, and microstructural analyses and changes in the microhardness. The XPA was performed with a DRON-2 diffractometer using CuK /SUB a/ radiation. Microstructural analysis showed that alloys containing 0-2, 33.3, and 50 mole % SmS were single-phase and the rest were two-phase

  18. Cross-section SmS-Ga2S3 of Sm-Ga-S ternary system

    International Nuclear Information System (INIS)

    The SmS-Ga2S3 system state diagram has been built up for the first time on the basis of the data of differential thermal, microstructural, and X-ray phase analyses and also according to the results of microhardness measurements. It has been established that ternary SmGa2S4, SmGa4S7 compounds are formed in the system

  19. Ba isotopic signature for early differentiation between Cs and Ba in natural fission reactors

    Science.gov (United States)

    Hidaka, Hiroshi; Gauthier-Lafaye, François

    2008-08-01

    Ba isotopic studies of the Oklo and Bangombé natural fission reactors in east Gabon provide information on the geochemical behavior of radioactive Cs ( 135Cs and 137Cs) in a geological medium. Large isotopic deviations derived from fissiogenic Ba were found in chemical leachates of the reactor uraninites. The fissiogenic Ba isotopic patterns calculated by subtracting the non-fissiogenic component are classified into three types that show different magnifications of chemical fractionation between Cs and Ba. In addition, the isotopic signatures of fissiogenic 135Ba, 137Ba and 138Ba suggest an early differentiation between Cs and Ba of less than 20 years after the production of fissiogenic Cs and Ba. On the other hand, only small excesses of 135Ba ( ɛ < +1.8) and/or 137Ba ( ɛ < +1.3) were identified in some clay samples, which might have resulted from selective adsorption of 135Cs and 137Cs that migrated from the reactors by differentiation.

  20. Identification of levels in neutron-rich 145Ce and 147Ce nuclei

    International Nuclear Information System (INIS)

    High-spin structures in the neutron-rich nuclei 145Ce and 147Ce produced in the spontaneous fission of 252Cf have been investigated by prompt γ-ray spectroscopy. A collective band structure in 145Ce is identified. Several sidebands along with the new high-spin states in 147Ce are also identified. Particle-plus-rotor model calculations indicate that the yrast bands in 145Ce and 147Ce most probably originate from coupling of the νi13/2 orbital to the ground states of 144Ce and 146Ce. The ground state configurations of 145,147Ce are (νh9/2+νf7/2) and νh9/2, respectively. (c) 1999 The American Physical Society

  1. Energy levels of the Ce activator relative to the YAP(Ce) scintillator host

    International Nuclear Information System (INIS)

    The electronic structure of the cerium-activated yttrium aluminum perovskite [YAP(Ce)] scintillator has been studied by core level x-ray spectroscopy and first-principles calculations. X-ray absorption and emission spectra at the oxygen K-edge of YAP(Ce) and CeO2 have been measured and compared with the calculated partial density of states. With the known band gap of CeO2, the measured oxygen K-edge absorption and emission spectra are used to construct a fixed relation between the valence and conduction bands of YAP and CeO2. This allows us to determine the fundamental band gap of YAP to be 8.1 ± 0.3 eV. A comparison between the cerium M4,5-edges x-ray absorption spectra of the YAP(Ce) and Ce model compounds (CeO2, CeF3, and Ce foils) then shows that the Ce activator is in the desired Ce3+, with a small fraction of Ce4+ due to oxidization at the surface. Finally, we determine that the ground state 4f1 energy level of the Ce3+ activator lies 1.8 ± 0.5 eV above the top of the valence band of the host YAP. (paper)

  2. The decay of 120Ba

    International Nuclear Information System (INIS)

    120Ba was produced by bombarding a 2 mg/cm2 thick 106Cd target with a 68 MeV 16O beam and fluorated in a helium-jet ion source. The decay of on-line mass separated activity 120Ba has been studied by γ-X, γ-γ and γ-β coincidence measurements. Its half-life was measured to be 24 ± 2s. The total decay energy was extracted to be QEG 5.0 ± 0.3 MeV. A simple decay scheme has been proposed

  3. Multi-seeding melt growth process of bulk Y-Ba-Cu-O superconductors for engineering applications

    Science.gov (United States)

    Wongsatanawarid, A.; Seki, H.; Murakami, M.

    2010-06-01

    We have prepared polycrystalline and four-domain Y-Ba-Cu-O superconductors in a molar ratio of Y123: Y211 = 10: 4 with lwt% Ce02 addition by melt-processing in air. Trapped field measurements showed that four sharp peaks were observed in a four-domain bulk sample, showing that four grains were successfully formed without defects by a multi-seeding method. Force measurements showed that a four-domain Y-Ba-Cu-O sample exhibited higher repulsive forces and smaller hysteresis loops than polycrystalline Y-Ba-Cu-O sample during the increasing and decreasing field processes, which implies higher pinning performance of the four-domain sample. With the aim of studying the transferable torque forces, we used a multi-pole magnet circuit with NSNS configuration. We confirmed that with the interaction of the magnet circuit, a four-domain Y-Ba-Cu-O sample showed larger forces than a polycrystalline sample both in the field-cooled and the zero-field-cooled mode. We also measured the torque forces acting between the magnet circuit and bulk Y-Ba-Cu-O samples by twisting the magnet circuit in the levitated state. Again a four-domain Y-Ba-Cu-O sample exhibited much higher torque forces than a polycrystalline sample. These results showed that multi-seeded Y-Ba-Cu-O sample with four-domains can be used for torque transfer apllications.

  4. Cross sections of deuteron induced reactions on $^{nat}$Sm for production of the therapeutic radionuclide $^{145}$Sm and $^{153}$Sm

    CERN Document Server

    Tárkányi, F; Takács, S; Ditrói, F; Csikai, J; Ignatyuk, A V

    2014-01-01

    At present, targeted radiotherapy (TR) is acknowledged to have great potential in oncology. A large list of interesting radionuclides is identified, including several radioisotopes of lanthanides, amongst them $^{145}$Sm and $^{153}$Sm. In this work the possibility of their production at a cyclotron was investigated using a deuteron beam and a samarium target. The excitation functions of the $^{nat}$Sm(d,x)$^{145153}$Sm reactions were determined for deuteron energies up to 50 MeV using the stacked-foil technique and high-resolution $\\gamma$-ray spectrometry. The measured cross sections and the contributing reactions were analyzed by comparison with results of the ALICE, EMPIRE and TALYS nuclear reaction codes. A short overview and comparison of possible production routes is given.

  5. Metallic nanowires on SmSi interface

    Energy Technology Data Exchange (ETDEWEB)

    Duverger, E; Palmino, F; Labrune, J C [Institut FEMTO-ST Dpt CREST, CNRS UMR 6174, 4 place Tharradin, BP 71427, 25211 Montbeliard cedex (France)

    2007-03-15

    The manufacture of nanowires and the exploitation of their specific properties are the great fields of fundamental and industrial research. Some nanostructuration can be obtained with the help of conventional lithography technics; nevertheless these technics are limited by the optical resolution, the introduction of many defects and the residual damage related to engraving. A new approach, which consists to create nanowires in-situ on pre structured SmSi(111) interface has been investigated by scanning tunneling microscopy (STM). This interface is known to permit the creation of many different 1D templates in the submonolayer range. We show in this study, the possibility to create Fe nano-objects of well-defined size distributed in an ordered array.

  6. Små dimser med store potentialer

    DEFF Research Database (Denmark)

    Mikkelsen, Bent Egberg; Dobroczynski, Michal; Gade, Rikke;

    2015-01-01

    Fødevare- og medialogiforskere på Aalborg Universitet har de seneste år udviklet og testet en række intelligente enheder. Fælles for dem er, at de er små og kan håndtere store mængder af data om forbrugernes adfærd. Et eksempel er FoodScape Tracker, som i realtid samarbejder med forbrugeren om, h......, hvad denne spiser. En anden ny enhed er Virtual Food Choice Simulator, som virtuelt kan simulere fødevareomgivelser i form af buffeter og supermarkeder uden udgifter til ombygning og fødevarer, og derved vise, hvad forbrugerne ser og ikke ser....

  7. Design of a novel optically stimulated luminescent dosimeter using alkaline earth sulfides doped with SrS:Eu,Sm materials

    Institute of Scientific and Technical Information of China (English)

    Yanping Liu; Zhaoyang Chen; Yanwei Fan; Weizhen Ba; Wu Lu; Qi Guo; Shilie Pan; Aimin Chang; Xinqiang Tang

    2008-01-01

    Optically stimulated luminescence (OSL) is the luminescence emitted from an irradiated insulator or semiconductor during exposure to light.The OSL intensity is a function of the dose of radiation absorbed by the sample and thus can be used as the basis of a radiation dosimetry method.Alkaline earth sulfides doped with rare-earth elements such as Ce,Sm and Eu are OSL dosimeters having very high sensitivity,and the OSL with a short time constant is separated from the stimulated light.In this paper,a novel OSL dosimeter designed with SrS:Eu,Sm materials is described.The dosimeter takes advantage of the characteristics of charge trapping materials SrS:Eu,Sm that exhibit OSL.The measuring range of the dosimeter is from 0.01 to 100Gy.The equipment,which is relatively simple and small in size,is promising for applications in space exploration and high dose radiation dosimetry.

  8. Effect of BaO on catalytic performance of Pd-based catalysts for purification of gasoline-methanol exhaust

    Institute of Scientific and Technical Information of China (English)

    张雪乔; 赵明; 徐成华; 汪嘉扬; 陈耀强

    2014-01-01

    Barium oxide was developed successfully to modify palladium catalysts supported on CeO2-ZrO2-La2O3-Al2O3 (CZLA) compound oxides by impregnation method. N2 adsorption (BET), X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the influence of BaO on the physicochemical properties of catalyst. And catalytic activity tests for methanol, CO, C3H8 and NO conversion were evaluated. Catalytic activity re-sults showed that BaO had a positive effect on the conversion of all pollutants. H2-TPR results suggested that the addition of BaO in-creased the reductive ability of the palladium catalysts. The XPS results indicated that doping BaO also improved the dispersion of Pd species and increased the amounts of Ce3+on the Pd-Ba/CZLA catalyst surface, which led to a better redox property. The excellent redox property helped to improve the catalytic activities toward all the pollutants over Pd-based catalysts.

  9. Micromagnetic Simulation of Magnetization Reversal in SmCo5/Sm2Co17 Magnets

    Institute of Scientific and Technical Information of China (English)

    荣传兵; 张宏伟; 杜晓波; 张健; 张绍英; 沈保根

    2004-01-01

    A three-dimensional finite element micromagnetic algorithm was developed to study the magnetization reversal of the SmCo5/Sm2Co17 based magnets. The influences of the microstructure and magnetic parameters on the coercivity were studied based on the model consisting of 64 irregular cells according to the experimental microstructure. Numerical results show that the coercivity increases with increasing the 2∶17-type cell size. Large cell boundary thickness leads to small coercivity. The drop of anisotropy constant of 1∶5 phase leads to the coercivity reducing, while the effect of exchange constant of 1∶5 phase on coercivity is contrary to that of exchange constant. The calculated field dependence of coercivity can be predicted by an inhomogeneous domain-wall pinning model. The microstructure parameter was analyzed by comparing the calculated coercivity.

  10. A Study of the Kinetics of the Electrochemical Deposition of Ce3+/Ce4+ Oxides

    Science.gov (United States)

    Valov, I.; Guergova, Desislava; Stoychev, D.

    The kinetics of cathodic electrodeposition of Ce3+ and/or Ce4+ oxides from alcoholic electrolytes on gold substrates has been studied. It was found that, depending on the oxygen content in the CeCl3-based electrolyte, Ce2O3 (in oxygen atmosphere) or CeO2 (in an inert atmosphere), respectively, were obtained. XPS studies clearly separated the two valence states of Ce ions in the oxide layers. The microstructure of the coatings was analyzed by atomic force microscopy (AFM).

  11. Phase equilibria in Sb2S3-SmS system

    International Nuclear Information System (INIS)

    Methods of physicochemical analysis is used to study Sb2S3-SmS cross section, which is a quasibinary one of Sm-Sb-S ternary system. Three new compounds: SmSb4S7, SmSb2S4 and Sm3Sb4S9 are formed in the system, the first one melts congruently, two others - incongruently. Solubility of Sb2S3 is 3 mol.% SmS at 300 K

  12. 4f and 5d energy levels of the divalent and trivalent lanthanide ions in M{sub 2}Si{sub 5}N{sub 8} (M=Ca, Sr, Ba)

    Energy Technology Data Exchange (ETDEWEB)

    Kate, O.M. ten, E-mail: o.m.tenkate@tudelft.nl [Luminescent Materials Research Group, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands); Energy Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600MB Eindhoven (Netherlands); Zhang, Z. [Energy Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600MB Eindhoven (Netherlands); Dorenbos, P. [Luminescent Materials Research Group, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands); Hintzen, H.T. [Energy Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600MB Eindhoven (Netherlands); Kolk, E. van der [Luminescent Materials Research Group, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands)

    2013-01-15

    Optical data of Sm, Tb and Yb doped Ca{sub 2}Si{sub 5}N{sub 8} and Sr{sub 2}Si{sub 5}N{sub 8} phosphors that have been prepared by solid-state synthesis, are presented. Together with luminescence data from literature on Ce{sup 3+} and Eu{sup 2+} doping in the M{sub 2}Si{sub 5}N{sub 8} (M=Ca, Sr, Ba) hosts, energy level schemes were constructed showing the energy of the 4f and 5d levels of all divalent and trivalent lanthanide ions relative to the valence and conduction band. The schemes were of great help in interpreting the optical data of the lanthanide doped phosphors and allow commenting on the valence stability of the ions, as well as the stability against thermal quenching of the Eu{sup 2+}d-f emission. Tb{sup 3+} substitutes on both a high energy and a low energy site in Ca{sub 2}Si{sub 5}N{sub 8}, due to which excitation at 4.77 eV led to emission from both the {sup 5}D{sub 3} and {sup 5}D{sub 4} levels, while excitation at 4.34 eV gave rise to mainly {sup 5}D{sub 4} emission. Doping with Sm resulted in typical Sm{sup 3+}f-f line absorption, as well as an absorption band around 4.1 eV in Ca{sub 2}Si{sub 5}N{sub 8} and 3.6 eV in Sr{sub 2}Si{sub 5}N{sub 8} that could be identified as the Sm{sup 3+} charge transfer band. Yb on the other hand was incorporated in both the divalent and the trivalent state in Ca{sub 2}Si{sub 5}N{sub 8}. - Graphical abstract: Energy level schemes showing the 4f ground states of the trivalent ( Black-Down-Pointing-Small-Triangle ) and divalent ( Black-Up-Pointing-Small-Triangle ) lanthanide ions and lowest energy 5d states of the trivalent ({nabla}) and divalent ({Delta}) ions with respect to the valence and conduction bands of Ca{sub 2}Si{sub 5}N{sub 8} (left) and Sr{sub 2}Si{sub 5}N{sub 8} (right). Highlights: Black-Right-Pointing-Pointer Construction of energy level schemes of all lanthanides within the M{sub 2}Si{sub 5}N{sub 8} hosts. Black-Right-Pointing-Pointer Construction was done by analyzing existing as well as new

  13. The effect of Pr co-dopant on the performance of solid oxide fuel cells with Sm-doped ceria electrolyte

    International Nuclear Information System (INIS)

    Samaria-doped ceria Ce0.9Sm0.1O1.95 (SDC) and samaria and praseodymium co-doped ceria Ce0.9Sm0.08Pr0.02O1.95 (SPDC) powders were synthesized by glycine nitrate process. SDC and SPDC electrolytes were made using the corresponding powders to press pellets and sinter them in air at 1400 deg. C. SEM and open porosity measurement showed the electrolytes were not dense and SPDC was more porous than SDC. Raman spectra indicated the oxygen vacancy concentration of SPDC was higher than SDC. Solid oxide fuel cells (SOFCs) with SPDC and SDC electrolytes were made and tested. The SOFC with SPDC electrolyte had higher power density but lower open circuit voltage. Impedance measurement was undertaken for the SOFCs at open circuit and the results showed that both the Ohmic and polarization resistances for SPDC electrolyte are smaller than for SDC. It is explained that co-doping Pr in Sm-doped ceria may increase the oxygen ionic conductivity by changing the grain boundary conditions so that more oxygen vacancies may exist and move faster. The electrochemical catalytic activity of Pr may play an important role in decreasing the polarization of electrolyte-electrode interface of the SOFCs

  14. Optic phonon anomalies and f-d hybridization in SmS and SmB6

    International Nuclear Information System (INIS)

    The optic phonons of semiconducting SmS and of (homogeneously) mixed-valent SmS and SmB6 have been investigated by means of Raman scattering. The dominant electron-phonon interaction upon resonantly exciting the 4f shell is revealed as a coupling of the strongly localized 4f hole at the Sm site to full symmetric (Asub(1g)) displacements of the nearest neighbour anions, i.e. mainly to LO(L) phonons. Semiconducting and mixed-valent, metallic SmS show a 'softening' of the LO(L) phonon frequencies with respect to the other divalent and trivalent rare earth sulfides, respectively, going in parallel with a 'softening' of the bulk modulus. The f-d hybridization is considered as the common origin of these phonon frequency renormalizations. (author)

  15. Phase formation in the BaB2O4-BaF2 system

    Science.gov (United States)

    Bekker, T. B.; Fedorov, P. P.; Kokh, A. E.

    2012-07-01

    It is shown that the BaB2O4-BaF2 system is quasi-binary with the following eutectics coordinates: 760°C, 59 mol % BaF2, 41 mol % BaB2O4. Due to the intense pyrohydrolysis during the growth of β-BaB2O4 crystals from the 55.6 mol % BaB2O4-44.4 mol % BaF2 composition, the Ba5B4O11 compound is formed in the system. This process leads to the cocrystallization of the β-BaB2O4 and Ba5B4O11 phases and impedes the formation of high-quality crystals.

  16. Thermal neutron capture cross sections for the 152Sm(n,γ) 153Sm and 154Sm(n,γ) 155Sm reactions at 0.0536 eV energy

    Science.gov (United States)

    Uddin, M. S.; Chowdhury, M. H.; Hossain, S. M.; Latif, Sk. A.; Islam, M. A.; Hafiz, M. A.; Mubin, S. H.; Zakaria, A. K. M.; Yunus, S. M.; Azharul Islam, S. M.

    2008-11-01

    The neutron capture cross sections for the 152Sm(n,γ) 153Sm and 154Sm(n,γ) 155Sm reactions at 0.0536 eV neutron energy were measured using an activation technique based on the TRIGA Mark-II research reactor, relative to the reference reaction 197Au(n,γ) 198Au. The activity was measured nondestructively using gamma-ray spectroscopy. Our measured values at this neutron energy are the first ones and are compared with 1/ v based evaluated cross sections reported in the ENDF/B-VII and JENDL-3.3 libraries. The measured value for the 152Sm(n,γ) 153Sm reaction is 0.28% lower than JENDL-3.3 and 0.48% higher than ENDF/B-VII. Our value for the production of 155Sm is about 3% and 2.3% higher than the evaluated value with ENDF/B-VII and JENDL-3.3 at 0.0536 eV, respectively.

  17. CeO2夹层在YSZ基SOFC中的研究进展%Research Progress on CeO2 Interlayer in YSZ-based SOFC

    Institute of Scientific and Technical Information of China (English)

    郝洪荣

    2009-01-01

    回顾了Y2O3、Sm2O3和Gd2O3掺杂的CeO2夹层(YDC、SDC和GDC)在Y2O3稳定的ZrO2(YSZ)基SOFC中的发展历史以及目前发展状况,分析了粉体的制备方法、夹层的沉积工艺、陶瓷烧结工艺对CeO2夹层性能的影响.从材料的化学相容性和热膨胀匹配等方面阐述了制备CeO2夹层的目的,对CeO2夹层大大提高电极性能进行了详尽的机理分析.指明了CeO2夹层对SOFC的重要作用和发展前景.

  18. A major Sm epitope anchored to sequential oligopeptide carriers is a suitable antigenic substrate to detect anti-Sm antibodies.

    Science.gov (United States)

    Petrovas, C J; Vlachoyiannopoulos, P G; Tzioufas, A G; Alexopoulos, C; Tsikaris, V; Sakarellos-Daitsiotis, M; Sakarellos, C; Moutsopoulos, H M

    1998-11-01

    A sensitive, highly reproducible, solid-phase enzyme immunoassay (ELISA), was developed in order to investigate whether the synthetic heptapeptide PPGMRPP-a major epitope of the Sm autoantigen-anchored in five copies to a sequential oligopeptide carrier (SOC), [(PPGMRPP)5-SOC5] is a suitable antigenic substrate to identify anti-Sm/antibodies. Sera with different autoantibody specificities [45 anti-Sm, 40 anti-U1RNP, 40 anti-Ro (SSA)/La(SSB) positive, 21 Antinuclear antibody positive, but negative for antibodies to extractable nuclear antigens (ANA + /ENA - ) and 75 normal human sera, ANA negative] and 75 sera from patients with rheumatoid arthritis (RA) were tested for anti-(PPGMRPP)5-(SOC)5 reactivity in order to evaluate the specificity and sensitivity of the method to detect anti-Sm antibodies. RNA immunoprecipitation assays for the detection of anti-Sm and anti-U1RNP antibodies and counter immunoelectrophoresis (CIE) for the detection of anti-Ro(SSA) and anti-La(SSB) antibodies were used as reference techniques. The sensitivity of the method was 98% and the specificity was 68% for the determination of anti-Sm antibodies, while for the determination of anti-Sm and/or anti-U1RNP reactivity (antibodies to snRNPs) the corresponding values were 82% and 86%, respectively. In a comparison of the above assay with an ELISA, using Sm/U1RNP purified complex as immobilized antigen it was shown that the sensitivity of the anti-Sm/U1RNP ELISA in detecting anti-snRNPs was 74%; in addition sera with anti-Sm antibodies gave higher binding in the anti-(PPGMRPP)5-(SOC)5 ELISA compared with anti-Sm/U1RNP ELISA. Intra- and inter-assay precision was measured on four sera with reactivities extending into a wide range of absorbance values showed that the intra-assay coefficient of variation (CV%) ranged from 2.7 to 6 and the inter-assay CV% ranged from 9 to 14.5. These results indicate that the PPGMRPP peptide anchored to a pentameric SOC as a carrier is a suitable antigen for

  19. Photoelectron spectra of CeO{sup −} and Ce(OH){sub 2}{sup −}

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Manisha; Felton, Jeremy A.; Kafader, Jared O.; Topolski, Josey E.; Jarrold, Caroline Chick, E-mail: cjarrold@indiana.edu [Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405 (United States)

    2015-02-14

    The photoelectron spectrum of CeO{sup −} exhibits what appears to be a single predominant electronic transition over an energy range in which numerous close-lying electronic states of CeO neutral are well known. The photoelectron spectrum of Ce(OH){sub 2}{sup −}, a molecule in which the Ce atom shares the same formal oxidation state as the Ce atom in CeO{sup −}, also exhibits what appears to be a single transition. From the spectra, the adiabatic electron affinities of CeO and Ce(OH){sub 2} are determined to be 0.936 ± 0.007 eV and 0.69 ± 0.03 eV, respectively. From the electron affinity of CeO, the CeO{sup −} bond dissociation energy was determined to be 7.7 eV, 0.5 eV lower than the neutral bond dissociation energy. The ground state orbital occupancies of both CeO{sup −} and Ce(OH){sub 2}{sup −} are calculated to have 4f 6s{sup 2} Ce{sup +} superconfigurations, with open-shell states having 4f5d6s superconfiguration predicted to be over 1 eV higher in energy. Low-intensity transitions observed at higher electron binding energies in the spectrum of CeO{sup −} are tentatively assigned to the {sup 1}Σ{sup +} (Ω = 0) state of CeO with the Ce{sup +2}⍰6s{sup 2} superconfiguration.

  20. Effect of fluxes on structure and luminescence properties of Y3Al5O12:Ce3+ phosphors

    Institute of Scientific and Technical Information of China (English)

    XU Shiqing; SUN Liuzheng; ZHANG Ying; JU Haidong; ZHAO Shilong; DENG Degang; WANG Huanping; WANG Baoling

    2009-01-01

    Ce3+-activated yttrium aluminum garnet (YAG) was prepared by the solid-state reaction, in which H3BO3, LiF, NaF, KF and BaF2 were used as the fluxes. The effect of fluxes on optical properties of phosphors was studied in detail, especially the fluxes of alkali fluorides, which could enhance the emission intensity and change the wavelength of emission peaks. Among these YAG:Ce phosphors, the phosphor sintered with H3BO3 and NaF exhibited the strongest emission. The emission peaks of phosphors prepared with fluxes from LiF to KF were shifted to long wavelength. The effect of NaF concentration on the emission intensity of YAG:Ce was also investigated. The value of emis-sion intensity reached the maximum when the concentration of NaF was 0.5%.

  1. Magnetic, thermodynamic and transport properties of novel non-centrosymmetric RCoSi3 (R=Pr, Nd and Sm) compounds

    Science.gov (United States)

    Nallamuthu, S.; Chandrasekaran, S. Selva; Murugan, P.; Reiffers, Marian; Nagalakshmi, R.

    2016-10-01

    Novel non-centrosymmetric RCoSi3 (R = Pr, Nd and Sm) compounds crystallize in tetragonal BaNiSn3 type structure with space group I4 mm. The bulk magnetic ordering of all the compounds were confirmed from heat capacity data. Magnetization measurements indicate that PrCoSi3 orders ferromagnetically at 5.9 K, while NdCoSi3 and SmCoSi3 order antiferromagnetically at 4 K and 8 K respectively. The magnetic transitions were also manifested by the slope change of temperature dependent resistivity at low temperatures. The energy level schemes created by crystal electric field splitting are determined from Schottky contribution to specific heat. The existence of magnon gap like features at low temperatures are consistent in both heat capacity and resistivity for NdCoSi3 and SmCoSi3. Large magnetoresistance is observed in NdCoSi3 and SmCoSi3. First principles electronic structure calculation based on density functional theory framework have been performed and compared with experimental data.

  2. Local structure of the Ce3+ ion the yellow emitting phosphor YAG:Ce

    NARCIS (Netherlands)

    Ghigna, P.; Pin, S.; Ronda, C.; Speghini, A.; Piccinelli, F.; Bettinelli, M.

    2011-01-01

    The local structure of the Ce3+ ion in the yellow emitting YAG:Ce phosphor has been studied by Extended X-ray Absorption Fine Structurespectroscopy in the 300−20 K temperature range. It has evidenced that the dopant Ce3+ replaces Y3+ in the garnet structure, giving rise to a significant expan

  3. The role of Ce(III) in BZ oscillating reactions

    Science.gov (United States)

    Nogueira, Paulo A.; Varela, Hamilton; Faria, Roberto B.

    2012-03-01

    Herein we present results on the oscillatory dynamics in the bromate-oxalic acid-acetone-Ce(III)/Ce(IV) system in batch and also in a CSTR. We show that Ce(III) is the necessary reactant to allow the emergence of oscillations. In batch, oscillations occur with Ce(III) and also with Ce(IV), but no induction period is observed with Ce(III). In a CSTR, no oscillations were found using a freshly prepared Ce(IV), but only when the cerium-containing solution was aged, allowing partial conversion of Ce(IV) to Ce(III) by reaction with acetone.

  4. Synthesis, crystal structure, and magnetism of A2Co12As7 (A=Ca, Y, Ce-Yb)

    Science.gov (United States)

    Tan, Xiaoyan; Ovidiu Garlea, V.; Chai, Ping; Geondzhian, Andrey Y.; Yaroslavtsev, Alexander A.; Xin, Yan; Menushenkov, Alexey P.; Chernikov, Roman V.; Shatruk, Michael

    2016-04-01

    Ternary intermetallics, A2Co12As7 (A=Ca, Y, Ce-Yb), have been synthesized by annealing mixtures of elements in molten Bi at 1223 K. The materials obtained crystallize in the P63/m variant of the Zr2Fe12P7 structure type. The unit cell volume shows a monotonic decrease with the increasing atomic number of the rare-earth metal, with the exception of Ce-, Eu-, and Yb-containing compounds. An examination of these outliers with X-ray absorption near edge structures (XANES) spectroscopy revealed mixed valence of Ce, Eu, and Yb, with the average oxidation states of +3.20(1), +2.47(5), and +2.91(1), respectively, at room temperature. Magnetic behavior of A2Co12As7 is generally characterized by ferromagnetic ordering of Co 3d moments at 100-140 K, followed by low-temperature ordering of rare-earth 4f moments. The 3d-4f magnetic coupling changes from antiferromagnetic for A=Pr-Sm to ferromagnetic for A=Ce and Eu-Yb. Polarized neutron scattering experiments were performed to support the postulated ferro- and ferrimagnetic ground states for Ce2Co12As7 and Nd2Co12As7, respectively.

  5. Study of Crystal Defect Behaviors in CeO2-Based Electrolyte

    Institute of Scientific and Technical Information of China (English)

    Ma Zhifang; Liang Guangchuan; Liang Jinsheng

    2004-01-01

    The defect behaviors, such as fundamental point defect, defect pair formation and oxygen vacancy migration in ceria, were studied on the basis of energy minimization calculations. The result shows that anion Frenkel disorder is the preferred intrinsic disorder, and it is easier to be dissolved in CeO2 for CaO and SrO than for MgO and BaO via an oxygen vacancy compensation mechanism. The association energy of an oxygen vacancy with a substitutional cation depends on dopant cation radius. The favorable migration route for oxygen vacancy with the lowest migration energy is from the second neighbor site to another one.

  6. Magnetic properties of Sm5Fe17 melt-spun ribbons and their borides

    Directory of Open Access Journals (Sweden)

    Tetsuji Saito

    2015-10-01

    Full Text Available Sm5Fe17 melt-spun ribbons exhibited low coercivity and partly or mostly consisted of the amorphous phase. Annealing of Sm5Fe17 melt-spun ribbon resulted in the formation of the Sm5Fe17 phase. The annealed Sm5Fe17 melt-spun ribbon exhibited a high coercivity. It was found that the addition of B to the Sm5Fe17 alloy resulted in the promotion of the Sm2Fe14B phase. Annealed Sm5Fe17Bx (x = 0.5 melt-spun ribbons consisted of the Sm5Fe17 phase together with the Sm2Fe14B and SmFe2 phases. On the other hand, annealed Sm5Fe17Bx (x = 1.0-1.5 melt-spun ribbons consisted of the Sm2Fe14B and SmFe2 phases without the Sm5Fe17 phase. The resultant Sm5Fe17Bx (x = 1.0-1.5 melt-spun ribbons still showed a coercivity of around 2 kOe. The annealed Sm5Fe17 melt-spun ribbon exhibited a high coercivity over 25 kOe and a remanence of 40 emu/g, whereas the annealed Sm5Fe17B1.0 melt-spun ribbon exhibited a high remanence of 65 emu/g and a coercivity of 2.0 kOe.

  7. Steam Electrolysis by Proton-Conducting Solid Oxide Electrolysis Cells (SOECs) with Chemically Stable BaZrO3-Based Electrolytes

    KAUST Repository

    Bi, Lei

    2015-07-17

    BaZrO3-based material was applied as the electrolyte for proton-conducting solid oxide fuel cells (SOECs). Compared with the instability of BaCeO3-based proton-conductors, BaZrO3-based material could be a more promising candidate for proton-conducting SOECs due to its excellent chemical stability under H2O conditions, but few reports on this aspect has been made due to the processing difficulty for BaZrO3. Our recent pioneering work has demonstrated the feasibility of using BaZrO3-based electrolyte for SOECs and the fabricated cell achieves relatively high cell performance, which is comparable or even higher than that for BaCeO3-based SOECs and offers better chemical stability. Cell performance can be further improved by tailoring the electrolyte and electrode. © The Electrochemical Society.

  8. Electrochemical synthesis of ammonia using a cell with a Nafion membrane and SmFe0.7Cu0.3-xNix03 (x =0-0.3) cathode at atmospheric pressure and lower temperature

    Institute of Scientific and Technical Information of China (English)

    XU GaoChao; LIU RuiQuan; WANG Jin

    2009-01-01

    Samaria-doped ceria Ce0.8Sm0.2O2-d(SDC) and SmFe0.7Cu0.3-xNixO3 have been synthesized by the sol-gel method and characterized by X-ray diffraction (XRD),transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The electrochemical synthesis of ammonia was investigated at atmospheric pressure and low temperature,using the SFCN materials as the cathode,a Nafion mem-brane as the electrolyte,nickel-doped SDC (Ni-SDC) as the anode and silver-platinum paste as the current collector. Ammonia was synthesized from 25 to 100? when the SFCN materials were used as cathode,with SmFe0.7Cu0.1Ni0.2O3 giving the highest rates of ammonia formation. The maximum rate of 90.4%.

  9. Sm1.5Sr0.5MO4 (M=Ni,Co,Fe) Cathode Catalysts for Ammonia Synthesis at Atmospheric Pressure and Low Temperature

    Institute of Scientific and Technical Information of China (English)

    XU,Gaochao; LIU,Ruiquan

    2009-01-01

    Sm1.5Sr0.5MO4 (M=Ni,Co,Fe) (SSM) catalysts were prepared by a sol-gel method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).Ammonia was synthesized from wet hydrogen and dry nitrogen at atmospheric pressure and low temperature (25-100 ℃) with applied voltage,using SSM as a cathode,Ni-Ce0.5Sm0.2O2-δ(Ni-SDC) as an anode,and silver-platinum film as a current collector,Nation proton exchange membrane as a proton permeating membrane.Several important factors on ammonia synthesis were investigated and the optimal synthetic temperature was found,at which the highest rate of evolution of ammonia was up to 1.05×10-8 mol·cm- 2·S-1.

  10. On Chinglish in C-E Interpretation

    Institute of Scientific and Technical Information of China (English)

    XIAO Gui-fang; LIU Jian-zhu; GUI Ren-na

    2005-01-01

    Based on the author's survey into the different interpretations of some terms from Chinese into English, the paper points out Chinglish exists universally in C-E interpretation.The author also puts forward some proposals on how to avoid and reduce Chinglish in the process of C-E interpretation after exploring its features and causes of Chinglish.

  11. The simultaneous mass and energy evaporation (SM2E) model.

    Science.gov (United States)

    Choudhary, Rehan; Klauda, Jeffery B

    2016-01-01

    In this article, the Simultaneous Mass and Energy Evaporation (SM2E) model is presented. The SM2E model is based on theoretical models for mass and energy transfer. The theoretical models systematically under or over predicted at various flow conditions: laminar, transition, and turbulent. These models were harmonized with experimental measurements to eliminate systematic under or over predictions; a total of 113 measured evaporation rates were used. The SM2E model can be used to estimate evaporation rates for pure liquids as well as liquid mixtures at laminar, transition, and turbulent flow conditions. However, due to limited availability of evaporation data, the model has so far only been tested against data for pure liquids and binary mixtures. The model can take evaporative cooling into account and when the temperature of the evaporating liquid or liquid mixture is known (e.g., isothermal evaporation), the SM2E model reduces to a mass transfer-only model.

  12. Fracture toughness studies in sintered SmCo5 magnets

    International Nuclear Information System (INIS)

    The fracture toughness of sintered SmCo5 magnets were systematically evaluated using both three point bend tests as well as Vickers indentation tests. These results were used for establishing the empirical dimensionless constant (χ) for evaluating indentation fracture toughness in SmCo5 magnets. The anisotropic behaviour of mechanical properties such as hardness, elastic modulus and fracture toughness was also investigated. - Highlights: • A strong anisotropy in the elastic modulus was observed in sintered SmCo5 magnet. • The hardness and fracture toughness did not show any prominent anisotropy. • Brittle cleavage fracture with (10 0) and (10 1) type cleavage planes observed. • Fracture toughness of SmCo5 magnets using Vickers indentation technique studied. • A suitable crack model and dimensionless coefficient value determined

  13. Discovery and characterization of smORF-encoded bioactive polypeptides.

    Science.gov (United States)

    Saghatelian, Alan; Couso, Juan Pablo

    2015-12-01

    Analysis of genomes, transcriptomes and proteomes reveals the existence of hundreds to thousands of translated, yet non-annotated, short open reading frames (small ORFs or smORFs). The discovery of smORFs and their protein products, smORF-encoded polypeptides (SEPs), points to a fundamental gap in our knowledge of protein-coding genes. Various studies have identified central roles for smORFs in metabolism, apoptosis and development. The discovery of these bioactive SEPs emphasizes the functional potential of this unexplored class of biomolecules. Here, we provide an overview of this emerging field and highlight the opportunities for chemical biology to answer fundamental questions about these novel genes. Such studies will provide new insights into the protein-coding potential of genomes and identify functional genes with roles in biology and disease. PMID:26575237

  14. Preparing different phases of Mg-Li-Sm alloys by molten salt electrolysis in LiCl-KCl-MgCl_2-SmCl_3 melts

    Institute of Scientific and Technical Information of China (English)

    韩伟; 田阳; 张密林; 叶克; 赵全友; 魏树权

    2010-01-01

    Different phases of Mg-Li-Sm alloys were prepared by galvanostatic electrolysis in LiCl-KCl-MgCl2-SmCl3 melts at 670 °C.The electrolysis process and phase control of Mg-Li-Sm alloys were studied.The microstructures of α,α+β,β phases of Mg-Li-Sm alloys were characterized by X-ray diffraction(XRD) and optical microscope(OM).Analysis of scanning electron microscopy(SEM) and EDS mapping analysis showed that Mg distributed homogeneously in Mg-Li-Sm alloys.EDS result showed that the distribution of Sm was more at...

  15. Lifetimes of Excited Levels in 131Ce

    Institute of Scientific and Technical Information of China (English)

    LI Guang-Sheng; LI Xian-Feng; WEN Li-Jun; ZHENG Yong-Nan; ZHENG Yong; LIU Yun-Zuo; YUAN Guan-Jun; YANG Chun-Xiang; MENG Rui; ZHU Li-Hua; ZHANG Zhen-Long; WANG Yue; WANG Zhi-Min; WEN Shu-Xian; LU Jing-Bin; ZHAO Guang-Yi

    2004-01-01

    @@ The fusion-evaporation reaction 116Sn (1gF, p3n) 131 Ce at projectile energy of 95 MeV is used to populate high spin states in 131 Ce. The de-exciting γ-rays are detected in γ-γ coincidence measurement with Compton-suppressed BGO-HPGe detectors. Level lifetimes of 131 Ce were determined by using the Doppler shift attenuation method.The experimental results indicate that collectivity of 131 Ce is reduced relative to that of 130 Ce and it follows that deformation decreases with increase of the neutron number on the basis of systematic comparison of transition quadrupole moments for the light cerium isotopes.

  16. Lattice dynamics of mixed-valent SmS

    International Nuclear Information System (INIS)

    Neutron scattering techniques have been used to measure the phonon dispersion curves for SmS in both the semiconducting and the metallic mixed-valent state. Large softening of the longitudinal acoustic phonon branches was found in the mixed-valent state, particularly for the [111] direction. It is apparent there is a strong coupling between the valence fluctuations and the phonons in the mixed-valent phase of SmS

  17. Concentration mechanism of piezoresistance in SmS

    International Nuclear Information System (INIS)

    Data on the SmS band structure are generalized and supplemented. A concentration model of the piezoresistance effect mechanism is proposed on the base of the data. It is shown that for production of a material with the piezoresistance exceeding the value for SmS at 300 K it is necessary to increase the contribution from 4f levels as far as possible

  18. Electric properties of SmS metallic modification

    International Nuclear Information System (INIS)

    Values of electric conductivity (rho and the Hall parameter Rsub(M) in thin films of samarium sulphide have been measured in semiconductor and metal modifications for the range of temperatures 1.5-300 K. Metal films of SmS with lattice constants 5.7 and 5.63 A are investigated. The temperature dependences of rho and Rsub(H) are theoretically explained. A zone scheme for metal modification of SmS is proposed

  19. The Fourth SM Family Neutrino at Future Linear Colliders

    CERN Document Server

    Çiftçi, A K; Sultansoy, S

    2005-01-01

    It is known that Flavor Democracy favors the existence of the fourth standard model (SM) family. In order to give nonzero masses for the first three family fermions Flavor Democracy has to be slightly broken. A parametrization for democracy breaking, which gives the correct values for fundamental fermion masses and, at the same time, predicts quark and lepton CKM matrices in a good agreement with the experimental data, is proposed. The pair productions of the fourth SM family Dirac $(\

  20. Temperature dependence of the scintillation properties of Ce:GSO and Ce:GSOZ

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Shunsuke, E-mail: kurosawa@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Sugiyama, Makoto [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yanagida, Takayuki [New Industry Creation Hatchery Center (NICHe), 6-6-10 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Yokota, Yuui [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yoshikawa, Akira [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center (NICHe), 6-6-10 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)

    2012-10-21

    The light output and decay times of Ce:GSO and Ce:GSOZ scintillators depend on Ce concentration and temperature. We investigated the temperature dependence of the light output and the decay time for Ce:GSO and Ce:GSOZ doped with 0.3 (only GSO), 0.5, 1.0, and 1.5 mol% Ce. These samples were measured with a ruggedized photomultiplier (PMT) (Hamamatsu R6877A) at 175 Degree-Sign C (in the thermostat chamber). Up to 100 Degree-Sign C, the relative light output of all of the samples remained within 10% after correcting the PMT gain, which depends on the temperature. The decay times of the GSO and GSOZ samples with the identical Ce concentrations were equal. Moreover, the quenching energy values for all the samples were equivalent.

  1. Energetics of nonequilibrium solidification in Al-Sm

    Science.gov (United States)

    Zhou, S. H.; Napolitano, R. E.

    2008-11-01

    Solution-based thermodynamic modeling, aided by first-principles calculations, is employed here to examine phase transformations in the Al-Sm binary system which may give rise to product phases that are metastable or have a composition that deviates substantially from equilibrium. In addition to describing the pure undercooled Al liquid with a two-state model that accounts for structural ordering, thermodynamic descriptions of the fcc phase, and intermediate compounds ( Al4Sm-β , Al11Sm3-α , Al3Sm-δ , and Al2Sm-σ ) are reanalyzed using special quasirandom structure and first-principles calculations. The possible phase compositions are presented over a range of temperatures using a “Baker-Cahn” analysis of the energetics of solidification and compared with reports of rapid solidification. The energetics associated with varying degrees of chemical partitioning are quantified and compared with experimental observations of the metastable Al11Sm3-α primary phase and reports of amorphous solids.

  2. Connection of thermopower and giant magnetothermopower with magnetic and structural heterogeneity in Sm{sub 0.55}Sr{sub 0.45}MnO{sub 3} manganite

    Energy Technology Data Exchange (ETDEWEB)

    Koroleva, L.I., E-mail: lyudkorolyova@yandex.ru [Moscow State University, Leninskie Gory 1, 119991 Moscow (Russian Federation); Morozov, A.S.; Jakhina, E.S. [Moscow State University, Leninskie Gory 1, 119991 Moscow (Russian Federation); Balbashov, A.M. [Moscow Power Institute, Krasnokazarmennaya street,14, 111250 Moscow (Russian Federation)

    2015-12-15

    It was first shown that the thermoelectric power in a magnetic semiconductor Sm{sub 0.55}Sr{sub 0.45}MnO{sub 3} is caused by ferromagnetic (FM) ferron-type nanoclusters and antiferromagnetic (AFM) CE-type nanoclusters with charge-orbital (CO) ordering. The presence of these clusters is caused by heavily Sr doping of a SmMnO{sub 3} compound, which replaced Sm ions. Thermoelectric power S and magnetothermopower ΔS/S has been studied in three samples: ceramics and two single-crystal samples. One of single-crystals was cooled in the air, another one was cooled in an oxygen atmosphere. The annealing in oxygen closes oxygen vacancies and, thus, increases the fraction of the CE-type AFM phase with the CO ordering which displaces the oxygen ions. S(T) curves of single-crystal sample cooled in the air and ceramic sample have a sharp increase starting from Curie temperature (T{sub C}) region and a slow decline till 325 K. At the same time {ΔS/S}(T) curves have a sharp minimum near T{sub C}=126 K, reaching the giant absolute value of 87% in the magnetic field H=14.17 kOe. This means that thermopower almost vanish with thermal destruction of FM clusters, i.e. thermopower is caused by these clusters in which crystal lattice is compressed. Oxygen cooled single-crystal's S(T) curves have a broad maximum near 270 K, including Neel temperature of CE-type clusters T{sub NCE}=240 K. {ΔS/S}(T) curve has a sharp minimum at the T{sub NCE} reaching the absolute value of 50% in H=13.2 kOe. The decrease of S is caused by destruction of CO order displacing oxygen ions in CE-type AFM clusters. Thus changed crystal lattice in nanoclusters of ferron type or AFM of CE-type makes the main contribution in thermopower in these three samples. - Highlights: • Thermopower S and magnetothermopower ΔS/S has been studied in Sm{sub 0.55}Sr{sub 0.45}MnO{sub 3}. • Sample consists of ferromagnetic and antiferromagnetic (AF) CE-type clusters. • Maxima of S and |ΔS/S| were observed at Curie

  3. AFe2As2 (A = Ca, Sr, Ba, Eu) and SrFe2-xTMxAs2 (TM = Mn, Co, Ni): crystal structure, charge doping, magnetism and superconductivity

    International Nuclear Information System (INIS)

    The electronic structure and physical properties of the pnictide compound families REOFeAs (RE=La, Ce, Pr, Nd, Sm), AFe2As2 (A=Ca, Sr, Ba, Eu), LiFeAs and FeSe are quite similar. Here, we focus on the members of the AFe2As2 family whose sample composition, quality and single-crystal growth are more controllable compared with the other systems. Using first-principles band structure calculations, we focus on understanding the relationship between the crystal structure, charge doping and magnetism in AFe2As2 systems. We will elaborate on the tetragonal to orthorhombic structural distortion along with the associated magnetic order and anisotropy, the influence of doping on the A site and the Fe site and the changes in the electronic structure as a function of pressure. Experimentally, we investigate the substitution of Fe in SrFe2-xTMxAs2 by other 3d transition metals, TM=Mn, Co or Ni. In contrast to a partial substitution of Fe by Co or Ni (electron doping), a corresponding Mn partial substitution does not lead to the suppression of the antiferromagnetic order or the appearance of superconductivity. Most of the calculated properties agree well with the measured properties, but several of them are sensitive to the As z position. For a microscopic understanding of the electronic structure of this new family of superconductors, this structural feature related to the Fe-As interaction is crucial, but its correct ab initio treatment still remains an open question.

  4. Phase equilibria in La(Y)-Ba-Cu-O systems and growth of high-Tc superconductor bulk single crystals

    International Nuclear Information System (INIS)

    The isobaric phase diagrams of BaO(La2O3)-CuO-CuO0.5 systems at a partial oxygen pressure of 0.021 MPa, the phase transition BaO2 right-reversible BaO at oxygen pressure up to 2.1 MPa have been studied and a flux method for growing bulk single crystals of YBa2Cu3O7-δ, La2CuO4, (LaSr)2CuO4, Nd2CuO4 and (NdCe)2CuO4 has been developed using a rotatable crucible which ensures separation of crystals from the melt

  5. Preparation and electromagnetic wave absorption properties of Sm2O3/α-Fe/Sm2Fe17Nx composites

    Science.gov (United States)

    Ye, Jinwen; Liu, Ying; Zhang, Jiao; Chen, Xianfu; Yao, Mingying

    2013-06-01

    Sm2O3/α-Fe/Sm2Fe17Nx composites were prepared in situ by hydrogenation-disproportionation-oxygen-desorption-recombination and nitrogen process, and their electromagnetic wave absorption properties were measured in the frequency range of 0.5-18 GHz. The result showed that saturation magnetization and coercivity of as-prepared powder with 25.3 wt% Sm2O3, 64.4 wt% α-Fe and 10.3 wt% Sm2Fe17N3 were 134.57 emu/g and 654.5 G, respectively. The dielectric constant of composites was low over the frequency range of 0.5-18 GHz, and their resonance frequencies were at a high frequency range. The resin composite of Sm2O3/α-Fe/Sm2Fe17N3 exhibited effective electromagnetic wave absorption (RL≤20 dB) in a frequency range 3-9 GHz, for absorber thickness ranging from 3 to 8 mm, respectively. A minimum reflection loss of -53 dB from the samples was observed at 7 GHz with an absorber thickness of 3.59 mm.

  6. Dielectric studies on cerium doped BaLa2Ti3O10

    Directory of Open Access Journals (Sweden)

    Parshuram B. Abhange

    2015-12-01

    Full Text Available The BaLa2-xCexTi3O10 samples (with x = 0.2, 0.4, 0.6 and 0.8 were prepared by hydroxide co-precipitation method and finally sintered at 1150 °C. The structure of the prepared samples was characterized by XRD and SEM. The single phase material was confirmed only for the BaLa1.8Ce0.2Ti3O10 ceramics. However, at higher cerium concentration secondary phase was observed. The characteristic plate-like structure, having grains with submicrometer thickness and high aspect ratio, was clearly observed by SEM. The results of dielectric measurement suggest that the appropriate adjustment of doping (with x between 0.2 and 0.8 will give sufficient high dielectric constant at very low loss. The resistivity of samples decreases with increase in temperature indicating the normal semiconducting electrical behaviour.

  7. Critically evaluated atomic transition probabilities for Ba I and Ba II

    International Nuclear Information System (INIS)

    Atomic transition probabilities for allowed and forbidden lines of Ba I and Ba II are tabulated, based on a critical evaluation of recent literature sources. The data are presented in multiplet format and are ordered by increasing excitation energies. (author)

  8. Role of SM22 in the differential regulation of phasic vs. tonic smooth muscle.

    Science.gov (United States)

    Rattan, Satish; Ali, Mehboob

    2015-04-01

    Preliminary proteomics studies between tonic vs. phasic smooth muscles identified three distinct protein spots identified to be those of transgelin (SM22). The latter was found to be distinctly downregulated in the internal anal sphincter (IAS) vs. rectal smooth muscle (RSM) SMC. The major focus of the present studies was to examine the differential molecular control mechanisms by SM22 in the functionality of truly tonic smooth muscle of the IAS vs. the adjoining phasic smooth muscle of the RSM. We monitored SMC lengths before and after incubation with pFLAG-SM22 (for SM22 overexpression), and SM22 small-interfering RNA. pFLAG-SM22 caused concentration-dependent and significantly greater relaxation in the IAS vs. the RSM SMCs. Conversely, temporary silencing of SM22 caused contraction in both types of the SMCs. Further studies revealed a significant reverse relationship between the levels of SM22 phosphorylation and the amount of SM22-actin binding in the IAS and RSM SMC. Data showed higher phospho-SM22 levels and decreased SM22-actin binding in the IAS, and reverse to be the case in the RSM SMCs. Experiments determining the mechanism for SM22 phosphorylation in these smooth muscles revealed that Y-27632 (Rho kinase inhibitor) but not Gö-6850 (protein kinase C inhibitor) caused concentration-dependent decreased phosphorylation of SM22. We speculate that SM22 plays an important role in the regulation of basal tone via Rho kinase-induced phosphorylation of SM22.

  9. AMiBA, XMM, and Cluster Surveys

    CERN Document Server

    Liang, H

    2001-01-01

    The Array for Microwave Background Anisotropy (AMiBA) is an interferometric array of 19 dishes co-mounted on a steerable platform and operating at 95GHz. One of the main scientific aims of AMiBA is to conduct cluster surveys using the Sunyaev-Zel'dovich (SZ) effect. Here we explore the potential of AMiBA as a tailor-made SZ instrument for the study of cluster physics and cosmology via cluster surveys out to the epoch of cluster formation. In particular, we explore the potential of combining AMiBA cluster surveys with the XMM-LSS (Large Scale Structure) survey.

  10. Cost objective PLM and CE

    CERN Document Server

    Perry, Nicolas

    2010-01-01

    Concurrent engineering taking into account product life-cycle factors seems to be one of the industrial challenges of the next years. Cost estimation and management are two main strategic tasks that imply the possibility of managing costs at the earliest stages of product development. This is why it is indispensable to let people from economics and from industrial engineering collaborates in order to find the best solution for enterprise progress for economical factors mastering. The objective of this paper is to present who we try to adapt costing methods in a PLM and CE point of view to the new industrial context and configuration in order to give pertinent decision aid for product and process choices. A very important factor is related to cost management problems when developing new products. A case study is introduced that presents how product development actors have referenced elements to product life-cycle costs and impacts, how they have an idea bout economical indicators when taking decisions during t...

  11. Enhanced time response of 1-in. LaBr{sub 3}(Ce) crystals by leading edge and constant fraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Vedia, V., E-mail: mv.vedia@ucm.es [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, ES-28040 Madrid (Spain); Mach, H. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, ES-28040 Madrid (Spain); National Centre for Nuclear Research, Division for Nuclear Physics, BP1, PL-00-681 Warsaw (Poland); Fraile, L.M.; Udías, J.M. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, ES-28040 Madrid (Spain); Lalkovski, S. [Faculty of Physics, University of Sofia, St. Kliment Ohridski, BG-1164 Sofia (Bulgaria)

    2015-09-21

    We have characterized in depth the time response of three detectors equipped with cylindrical LaBr{sub 3}(Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurements were performed at {sup 60}Co and {sup 22}Na γ-ray energies against a fast BaF{sub 2} reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the parameters of the constant fraction discriminator, namely the zero-crossing and the external delay. We report here on the optimal time resolution of the three crystals. It is observed that timing properties are influenced by the amount of Ce doping and the crystal homogeneity. For the crystal with 8% of Ce doping the use of the ORTEC 935 CFD at very shorts delays in addition to the Hamamatsu R9779 PMT has made it possible to improve the LaBr{sub 3}(Ce) time resolution from the best literature value at {sup 60}Co photon energies to below 100 ps.

  12. Enhanced time response of 1-in. LaBr3(Ce) crystals by leading edge and constant fraction techniques

    CERN Document Server

    Vedia, V; Fraile, L M; Udias, J M; Lalkovski, S

    2015-01-01

    We have characterized in depth the time response of three detectors equipped with cylindrical LaBr$_{3}$ (Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurements were performed at $^{60}$Co and $^{22}$Na {\\gamma}-ray energies against a fast BaF$_{2}$ reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the parameters of the constant fraction discriminator, namely the zero-crossing and the external delay. We report here on the optimal time resolution of the three crystals. It is observed that timing properties are influenced by the amount of Ce doping and the crystal homogeneity. For the crystal with 8% of Ce doping the use of the ORTEC 935 CFD at very shorts delays in addition to the Hamamatsu R9779 PMT has made it possible to improve the LaBr$_{3}$(Ce) time resolution from the best literature value at 60Co photon energies to below 100 ps.

  13. Weak Ferromagnetism and Multiple Metamagnetic Transitions in the Non-centrosymmetric Tetragonal Compound CePdSi3

    Science.gov (United States)

    Ueta, Daichi; Ikeda, Yoichi; Yoshizawa, Hideki

    2016-10-01

    We have succeeded in growing single crystalline samples of CePdSi3 with the BaNiSn3-type non-centrosymmetric structure. Specific heat, magnetic susceptibility, and magnetization measurements were carried out, which revealed three successive magnetic transitions at TI = 4.85(5) K, TII = 2.78(5) K, and TIII = 2.30(5) K at zero field. Below TII, a weak ferromagnetic component was observed, indicating a canted antiferromagnetic ground state in CePdSi3. The observed large magnetic anisotropy in CePdSi3 was explained in terms of a simple crystalline-electric-field model. From the magnetization measurements, we identified five (three) magnetic states in the H-T phase diagrams for the H || [100] ([001]) direction. Interestingly, only three magnetization steps were observed for H || [110], suggesting the existence of the in-plane magnetic anisotropy in CePdSi3. We discuss a possible nature of the complex magnetic properties of CePdSi3.

  14. Směrování v IP sítích s využitím sociálních sítí

    OpenAIRE

    Němec, Jan

    2014-01-01

    Tato bakalářská práce se věnuje problematice směrování dat v mobilních sítích. První část práce se zabývá přetěžováním mobilních sítí a popisem DTN a oportunistických sítí. V další části se práce zabývá popisem protokolů, které zapadají do konceptu směrování na základě sociálního statusu. Poslední část práce se zabývá návrhem a realizací simulačního modelu pro vybraný protokol z předešlé části.

  15. AMiBA: System Performance

    OpenAIRE

    Lin, Kai-Yang; Li, Chao-Te; Ho, Paul T. P.; Huang, Chih-Wei Locutus; Liao, Yu-Wei; Liu, Guo-Chin; Koch, Patrick M.; Molnar, Sandor M.; Nishioka, Hiroaki; Umetsu, Keiichi; Wang, Fu-Cheng; Wu, Jiun-Huei Proty; Kestevan, Michael; Birkinshaw, Mark; Altamirano, Pablo

    2009-01-01

    The Y.T. Lee Array for Microwave Background Anisotropy (AMiBA) started scientific operation in early 2007. This work describes the optimization of the system performance for the measurements of the Sunyaev-Zel'dovich effect for six massive galaxy clusters at redshifts $0.09 - 0.32$. We achieved a point source sensitivity of $63\\pm 7$ mJy with the seven 0.6m dishes in 1 hour of on-source integration in 2-patch differencing observations. We measured and compensated for the delays between the an...

  16. Study on structure and magnetic entropy changes of Ce2-xPrxFe16.5Co0.5 alloys

    Institute of Scientific and Technical Information of China (English)

    ZHONG Xichun; ZENG Dechang; LUO Zhijian

    2006-01-01

    A series of Ce2-xPrxFe16.5Co0.5 alloys were preparedby arc melting under purified argon atmosphere. The structure and magnetic entropy changes in Ce2-xPrxFe16.5Co0.5 alloys were investigated by means of X-ray diffraction pattern and MPMS XL-7 magnetometer. The experimental results show that the crystal structure of Ce2-xPrxFe16.5Co0.5 alloys keeps in TH2Zn17-type rhombohedral, and the Curie temperature of Ce2-xPrxFe16.5Co0.5 alloys can be shifted to room temperature around by a composition adjustment. The magnetic entropy changes (-ΔSM) in Ce2-xPrxFe16.5Co0.5 alloys are relatively large, and a platform of magnetic entropy changes appearsnear the temperature TC. Ce2-xPrxFe16.5Co0.5 alloys are the potential working media for magnetic refrigeration with their stable chemical properties and especially low price.

  17. Morphological stability of Sm123 superconductor during peritectic solidification from Sm211 + L mixture

    International Nuclear Information System (INIS)

    The interface stability of the Sm 123 superconductor was analyzed in accordance with the constitutional undercooling criterion. As the single-crystal growth of the 123 phase is largely dependent on the growth-interface stability, a quantitative analysis was very much required. From this analysis, it was clarified that the constitutional undercooling must exist in the liquid when the 123 growth interface comes close to a 211 particle during the peritectic solidification. It was also predicted that the larger 211 particle radius, smaller volume fraction of the 211 particles, larger growth rate, or smaller imposed temperature gradient would cause easy occurrence of the constitutional undercooling ahead of the 123 growth interface. Taking into account the nucleation at the L/211 interface just ahead of the 123 growth front due to the constitutional undercooling, the transition of 123 growth from a planar-interface morphology to an equiaxed blocky morphology was investigated quantitatively and qualitatively

  18. Strong broad green UV-excited photoluminescence in rare earth (RE = Ce, Eu, Dy, Er, Yb) doped barium zirconate

    Energy Technology Data Exchange (ETDEWEB)

    Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Ciudad de Mexico, D. F. 07730 (Mexico); Meza, O. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico)

    2011-10-25

    Highlights: > Trivalent rare earth (RE) substitution on Zr{sup 4+} sites in BaZrO{sub 3} lead to band gap narrowing. > RE substitution lead to enhanced blue-green intrinsic emission of nanocrystalline BaZrO{sub 3} > Blue-green hue of BaZrO3:RE depends on RE dopant and excitation UV wavelength > BaZrO3: Dy{sup 3+} PL chromatic coordinates correspond to pure white color coordinates of CIE 1931 model - Abstract: The wet synthesis hydrothermal method at 100 deg. C was used to elaborate barium zirconate (BaZrO{sub 3}) unpurified with 0.5 mol% of different rare earth ions (RE = Yb, Er, Dy, Eu, Ce). Morphological, structural and UV-photoluminescence properties depend on the substituted rare earth ionic radii. While the crystalline structure of RE doped BaZrO{sub 3} remains as a cubic perovskite for all substituted RE ions, its band gap changes between 4.65 and 4.93 eV. Under 267 nm excitation the intrinsic green photoluminescence of the as synthesized BaZrO{sub 3}: RE samples is considerably improved by the substitution on RE ions. For 1000 deg. C annealed samples, under 267 nm, the photoluminescence is dominated by the intrinsic BZO emission. It is interesting to notice that Dy{sup 3+}, Er{sup 3+} and Yb{sup 3+} doped samples present whitish emissions that might be useful for white light generation under 267 nm excitation. CIE color coordinates are reported for all samples.

  19. Lepivost tkaniny nánosované vrstvou gumárenské směsi

    OpenAIRE

    Mahel, Jindřich

    2013-01-01

    Teoretická část diplomové práce popisuje základní skladbu gumárenské směsi, metody používané k jejímu zpracování a shrnuje dosavadní poznatky v oblasti lepivosti. Experimentální část se zabývá návrhem metod akcelerovaného stárnutí, pomocí nichž bylo provedeno testování vlivu UV záření, ozonu, teploty a vlhkosti na konfekční lepivost. Po slepení definovaným tlakem byla konfekční lepivost stanovena pomocí odlupovacího testu. Povrchy vzorků byly charakterizovány pomocí rastrovací elektronové mik...

  20. Soil-to-plant transfer factors of radioactive Ca, Sm and Pd isotopes: critical assessment of the use of analogies to derive best-estimates from existing non-specific data

    International Nuclear Information System (INIS)

    45Ca, 151Sm and 107Pd are three radionuclides present in low to intermediate in activity radioactive wastes for which no soil-to-plant Transfer Factors (TF) values are available to be used in biosphere models for Ecological Risk Assessment. In the absence of specific radioecological studies, this work reviews and analyzes the existing literature for stable isotopes of Pd, Sm and Ca in order to derive best estimates for TF values that could be used as Transfer Factors. Alternative methods of extrapolation are also critically assessed. The values have been classified according to climatic zone, plant class and soil type for each element. The overall geometric mean TF values (for all plants and conditions) was calculated as 8.4E-02 for Pd, for which the value of radioRu in TRS-472 is also available. The mean TF for Sm was 4.2E-04. This value was lower than the TF values for radioactive Ce that are proposed as alternative values for Sm in TRS-472. The former may be relevant for long term assessments and the latter could possibly used to describe the short term 151Sm post-release behaviour. The mean value for Ca is 2.3E-01 but varies considerably among plants of a given class due to the variety of plant Ca uptake behaviors. Alternatively, to limit this variability, Ca data content for dry plant matter, as analyzed using the phylogenetic method, could be used to derive TF values if the conservation of isotopic ratio of 45Ca to stable Ca in soils and in plants hypothesis is taken into account. The TF for Ca in sub-tropical zones is 10-fold lower than in temperate zones. There is a lot of data available about exchangeable Ca in soil, which mean that we could calculate an available TF. The analysis shows that Ca bioavailability is also a key factor within transfer. - Highlights: • Derivation of TF values for Pd, Sm and Ca based on stable isotope literature. • Assessment of alternative values for Pd based on radioactive Ru values from TRS-472 (IAEA). • Assessment of

  1. Bäuerliche Selbstorganisation, bäuerliches Erfahrungswissen und bäuerlicher Widerstand in Belarus

    Directory of Open Access Journals (Sweden)

    Konrad Berghuber

    2015-06-01

    Full Text Available Ausgehend vom Commonsdiskurs und von anarchistischen Vorstellungen über bäuerliches Leben als Vorbild für eine solidarische Gesellschaft untersucht der vorliegende Artikel bäuerliche Selbstorganisation, bäuerliches Erfahrungswissen und bäuerliche Kämpfe gegen herrschende Schichten auf dem Gebiet von Belarus seit der Abschaffung der Leibeigenschaft 1861. Anhaltspunkte bäuerlicher Selbstorganisation stellen die Obschtschina sowie Kooperationen bei der Produktion und der Maschinennutzung während der sowjetischen „neuen Wirtschaftspolitik“ dar. Lokales Erfahrungswissen wird ebenso in der Obschtschina und in den privaten Nebenlandwirtschaften der Kolchosen- und Sowchosenarbeiter_innen verortet. Offenen Widerstand gegen die Herrschenden leisteten Bauern und Bäuerinnen aufgrund ihrer Situation bis in die 1930er Jahre. Er erreichte seine Höhepunkte während der Revolutionen 1905-07 und 1917, während der Kollektivierung der Landwirtschaft und während der Wirtschaftskrise Anfang der 1930er Jahre. Danach hatten die Widerstandshandlungen eine verdecktere Form. Diese Kämpfe von Bauern und Bäuerinnen um Land und Unabhängigkeit sind vergleichbar mit bäuerlichen Kämpfen in anderen Ländern.

  2. The magnetoelectric coupling in rhombohedral-tetragonal phases coexisted Bi{sub 0.84}Ba{sub 0.20}FeO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Wei Wei [School of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Xuan Haicheng; Wang Liaoyu [Department of Physics, Nanjing University, Nanjing 210008 (China); Zhang Yan [Department of Physics, Southeast University, Nanjing 211189 (China); Shen Kai, E-mail: shenkai84@nuaa.edu.cn [School of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Wang Dunhui [Department of Physics, Nanjing University, Nanjing 210008 (China); Qiu Teng [Department of Physics, Southeast University, Nanjing 211189 (China); Xu Qingyu, E-mail: xuqingyu@seu.edu.cn [Department of Physics, Southeast University, Nanjing 211189 (China); Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China)

    2012-06-15

    Ba doped Bi{sub 1.04-x}Ba{sub x}FeO{sub 3} ceramics with x up to 0.30 have been prepared by the tartaric acid modified sol-gel method. The X ray diffraction patterns show that the structure transforms from rhombohedral to tetragonal with increasing the Ba substitution concentration from 10% to 30% and the coexistence of distorted rhombohedral and tetragonal phases in 20% Ba substituted BiFeO{sub 3}, which was further confirmed by the Raman spectra. Bi{sub 0.84}Ba{sub 0.20}FeO{sub 3} exhibits the highest magnetization (1.6 emu/g under magnetic field of 12 kOe) compared with the other samples of different Ba substitution concentration. Significant enhancement of the ferroelectricity has been observed in 20% and 30% Ba substituted BiFeO{sub 3} with saturate polarization close to 6.6 {mu}C/cm{sup 2} for Bi{sub 0.74}Ba{sub 0.30}FeO{sub 3}. The magnetoelectric coupling of Bi{sub 0.84}Ba{sub 0.20}FeO{sub 3} has been measured and the maximum decrease of magnetization under magnetic field of 9.8 kOe was about 0.06 emu/g with increasing applied electric field to 11 kV/cm, and the magnetoelectric coefficient is 1.5 Multiplication-Sign 10{sup -12} s/m.

  3. BaBar Data Aquisition

    CERN Document Server

    Scott, I; Grosso, P; Hamilton, R T; Huffer, M E; O'Grady, C; Russell, J J

    1998-01-01

    The BaBar experiment at the Stanford Linear Accelerator Center is designed to perform a search for CP violation by analysing the decays of a very large sample of B and Bbar mesons produced at the high luminosity PEP-11 accelerator. The data acquisition system must cope with a sustained high event rate, while supporting real time feature extraction and data compression with minimal dead time. The BaBar data acquisition system is based around a common VME interface to the electronics read-out of the separate detector subsystems. Data from the front end electronics is read into commercial VME processors via a custom "personality card" and PCI interface. The commercial CPUs run the Tornado operating system to provide a platform for detector subsystem code to perform the necessary data processing. The data are read out via a non-blocking network switch to a farm of commercial UNIX processors. Careful design of the core data acquisition code has enabled us to sustain events rates in excess of 20 kHz while maintaini...

  4. Potential rare-earth modified CeO2 catalysts for soot oxidation. Part 2. Characterisation and catalytic activity with NO + O2

    International Nuclear Information System (INIS)

    Ceria (CeO2) and rare-earth modified ceria (CeReOx with Re = La3+, Pr3+/4+, Sm3+, Y3+) supports and Pt impregnated supports are studied for the soot oxidation under a loose contact with the catalyst with the feed gas, containing NO + O2. The catalysts are characterised by XRD, H2-TPR, DRIFT and Raman spectroscopy. Among the single component oxides, CeO2 is significantly more active compared with the other lanthanide oxides used in this study. Doping CeO2 with Pr3+/4+ and La3+ improved, however, the soot oxidation activity of the resulting solid solutions. This improvement is correlated with the surface area in the case of CeLaOx and to the surface area and redox properties of CePrOx catalyst. The NO conversion to NO2 over these catalysts is responsible for the soot oxidation activity. If the activity per unit surface area is compared CePrOx is the most active one. This indicates that though La3+ can stabilise the surface area of the catalyst in fact it decreases the soot oxidation activity of Ce4+. The lattice oxygen participates in NO conversion to NO2 and the rate of this lattice oxygen transfer is much faster on CePrOx. In general, the improvement of the soot oxidation is observed over the Pt impregnated CeO2 and CeReOx catalysts, and can be correlated to the presence of Pt . The surface reduction of the supports in the presence of Pt occurred below 100 C. The surface redox properties of the support in the Pt catalysts do not have a significant role in the NO to NO2 conversion. In spite of the lower surface area, the Pt/CeYOx and Pt/CeO2 catalysts are found to be more active due to larger Pt crystal sizes. The presence of Pt also improved the CO conversion to CO2 over these catalysts. The activation energy for the soot oxidation with NO + O2 is found to be around 50 kJ/mol. (author)

  5. Structural and magnetic properties of Ce/Fe and Ce/FeCoV multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mannix, D.; Stirling, W.G. [Liverpool Univ. (United Kingdom); Lander, G.H.

    1997-09-01

    Ce/Fe and Ce/FeCoV multilayers have been grown by magnetron sputtering. The interfaces are well defined and the layers are crystalline down to an individual layer thickness of 20 A. Ce/FeCoV multilayers show sharper interfaces than Ce/Fe but some loss of crystallinity is observed. Hysteresis loops obtained by SQUID show different behaviour of the bulk magnetisation as a function of the layer thickness. Fe moments are found by Moessbauer spectroscopy to be perpendicular to the interfaces for multilayers with small periodicity. (author) 2 figs., 2 refs.

  6. Two- and Three-Body Charmless B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Stracka, Simone; /Milan U. /INFN, Milan

    2012-04-05

    We report recent measurements of rare charmless B decays performed by BaBar. The results are based on the final BaBar dataset of 424 fb{sup -1} collected at the PEP-II B-factory based at the SLAC National Accelerator Laboratory. The study of rare B decays is a key ingredient to meet two of the main goals of the B-factories: assessing the validity of the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP-violation by precisely measuring the elements of the Unitarity Triangle (UT), and searching for hints of New Physics (NP), or otherwise constraining NP scenarios, in processes which are suppressed in the Standard Model (SM). In loop processes, in particular, NP at some higher energy scale may manifest itself in the low energy effective theory as new couplings, such as those introduced by new very massive virtual particles in the loop. In NP searches hadronic uncertainties can play a major role, expecially for branching fraction measurements. Many theoretical uncertainties cancel in ratios of amplitudes, and most NP probes are therefore of this kind. In the following sections we report recent measurements, performed by the BaBar Collaboration, that are relevant to NP searches in charmless hadronic B decays.

  7. Effect of cerium substitution on structural and impedance properties of 0.8Ba0.2(Bi0.5K0.5)TiO3 lead free ceramic system

    Science.gov (United States)

    Ramesh, M. N. V.; Ramesh, K. V.

    2016-01-01

    Cerium-doped 0.8BaTiO3-0.2Bi0.5K0.5TiO3 with composition 0.8Ba0.2(Bi0.5K0.5)Ti1-xCexO3 where x = 0.01, 0.02, 0.03, 0.04, 0.05, 0.06 lead free ceramics were prepared by conventional solid state reaction method followed by high energy ball milling. X-ray diffraction studies confirm the tetragonal structure at room temperature for all the Ce-doped samples. Lattice parameters and density were increasing with increase of Ce doping. Frequency and temperature dependent dielectric studies were carried out and indicate that the dielectric constant and Curie temperature are decreasing with increasing of Ce doping. All the Ce-doped samples exhibiting diffused and dispersive phase transitions with degree of diffuseness ranging from 1.4 to 2 calculated from the modified Curie-Weiss law. Impedance studies confirms the temperature dependent non-Debye kind of relaxation process in the material. From the Cole-Cole plots measured at high temperatures, reveals that the grain effect in the all Ce-doped samples. Impedance analysis studies also support the X-ray diffraction and dielectric studies that occupation of Ce both at A-site and B-site for small values of Ce doping.

  8. Magnetic property and microstructure of SmCo magnetic recording films

    Institute of Scientific and Technical Information of China (English)

    LI; Ning; LI; Shuai

    2009-01-01

    Cr/SmCo/Cr thin films with Sm concentration of 37.7 at.% were deposited on glass substrates by magnetron sputtering. Meas-urement of magnetic properties showed that the SmCo film possessed good magnetic anisotropy, a high coercivity of 3019 kA/m and low magnetic exchange coupling. Microstructure analysis showed that crystallized SmCo5 magnetic phase, non-magnetic SmCo2 phase and Sm2Co7 phase co-existed ill the film. The non-magnetic SmCo2 phase might function as isolator of SmCo grains, leading to a decrease of magnetic exchange coupling. Moreover, a Cr2)3 oxide layer which could protect the SmCo layer from oxidation formed at the surface of the Cr cap layer.

  9. Effect of SiO2 addition on the dielectric properties and microstructure of BaTiO3-based ceramics in reducing sintering

    Institute of Scientific and Technical Information of China (English)

    Ying-chieh Lee; Wei-hua Lu; Su-hei Wang; Chai-wei Lin

    2009-01-01

    The effect of SiO2 doping on the sintering behavior,microstructure,and dielectric properties of BaTiO3-based ceramics has been investigated.Silica was added to the BaTiO3-based powder prepared by the solid state method with 0.075mo1%,0.15mo1%,and 0.3mo1%,respectively.The SiO2-doped BaTiO3-based ceramic with high density and uniform grain size were obtained,which were sintered in reducing atmosphere.A scanning electron microscope,X-ray diffraction,and LCR meter were used to determine the microstructure as well as the dielectric properties.SiO2 can form a liquid phase belonging to the ternary system of BaO-TiO2-SiO2,leading to the formation of BaTiO3 ceramics with high density at a lower sintering temperature.The SiO2-doped BaTiO3-based ce-ramics can be sintered to a theoretical density higher than 95% at 1220℃ with a soaking time of 2 h.The dielectric constants of the sample with 0.15mo1% SiO2 addition sintered at 1220℃ is about 9000.Doping with a small amount of silica can improve the sinter-ing and dielectric properties of BaTiO3-based ceramics.

  10. High spin states of 120Ba

    International Nuclear Information System (INIS)

    The very neutron deficient nucleus 120Ba has been investigated in a high-spin γ-spectroscopic study. The yrast band of 120Ba is extended up to spin 22 ℎ and one tentatively assigned negative-parity side band is observed up to spin 15 ℎ. The experimental results are compared with Total Routhian Surface calculations. (orig.)

  11. CONTRAST STUDY ON CT AND BA IN 3000 PATIENTS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objectives: To explore clinical applied value on CT and BA in diagnosis of diseases. Methods:CT and BA were examined in 3000 patients. Results: There were some differences between CT and BA in diagnosis of diseases. Conclusions: BA can supplement shortage of CT. The combination of CT and BA can heighten diagnostic level of diseases.KEY WORDS brain atlas (BA); computed tomography (CT)

  12. Sodium samarium tetrakis(polyphosphate, NaSm(PO34

    Directory of Open Access Journals (Sweden)

    Dan Zhao

    2010-07-01

    Full Text Available NaSm(PO34 has been prepared by solid state reactions. It belongs to type II of the structural family of MILnIII(PO34 compounds (MI = alkali metal and LnIII = rare earth metal and is composed of ∞(PO3n]n− polyphosphate chains with a repeating unit of four PO4 tetrahedra. The chains extend parallel to [100] and share O atoms with irregular SmO8 polyhedra, forming a three-dimensional framework which delimits tunnels occupied by Na+ cations in a distorted octahedral environment.

  13. The Appliance of Code Switching in the SM Language

    Institute of Scientific and Technical Information of China (English)

    LI Chang

    2014-01-01

    Code-switching, a natural phenomenon that consists of alternating two or more languages in bilinguals ’discourse, has traditionally been examined in its oral production. For over three decades, much attention has been emphasized on its form, meaning, and grammatical patterns. However, very little research focuses on code-switching in short message form. Code switch-ing is a quite common phenomenon. As cell phones become the communication tools used by people more frequently, short mes-sage language (SM) attracts more attention by people. Through analyzing the code switching in the SM language, it will help us understand more about its use and explore more information for our study.

  14. Piezoresistivity of SmS at room temperature

    International Nuclear Information System (INIS)

    Dependence of the longitudinal coefficient of piezoresistance of unaixial compression (π11) on conductivity electron concentration (n) at room temperature for SmS monocrystals was studied. Comparative analysis of the obtained experimental results with calculated dependences of π11 on n was carried out. It was concluded as a result of the analysis that the value of piezoresistance effect is specified by contribution of electrons activated from 4f-levels of Sm ions and from impurity donor levels to charge carrier concentration

  15. Pressure-induced elastic softening of SmS

    International Nuclear Information System (INIS)

    Elastic constant measurements under hydrostatic pressure show that, as semiconducting SmS approaches its type O isostructural transition from the larger-volume side, the bulk modulus decreases but not in the catastrophic manner characteristic of the intermediate-valence Smsub(1-x)Ysub(x)S alloys near the transition. In both the semiconducting SmS and the intermediate-valence metallic-state Smsub(1-x)Ysub(x)S alloys the contribution from cubic terms to the elastic strain energy is small. (author)

  16. Presence of magnetic excitations in SmFeAsO

    Science.gov (United States)

    Pelliciari, Jonathan; Dantz, Marcus; Huang, Yaobo; Strocov, Vladimir N.; Xing, Lingyi; Wang, Xiancheng; Jin, Changqing; Schmitt, Thorsten

    2016-09-01

    We measured dispersive spin excitations in SmFeAsO, a parent compound of SmFeAsO1 -xFx and one of the highest temperature superconductors of Fe pnictides (TC ≈ 55 K). We determine the magnetic excitations to disperse with a bandwidth energy of ca 170 meV at (0.47, 0) and (0.34, 0.34), which merges into the elastic line approaching the Γ point. Comparing our results with other parent Fe pnictides, we show the importance of structural parameters for the magnetic excitation spectrum, with small modifications of the tetrahedron angles and As height strongly affecting the magnetism.

  17. Petri nets SM-cover-based on heuristic coloring algorithm

    Science.gov (United States)

    Tkacz, Jacek; Doligalski, Michał

    2015-09-01

    In the paper, coloring heuristic algorithm of interpreted Petri nets is presented. Coloring is used to determine the State Machines (SM) subnets. The present algorithm reduces the Petri net in order to reduce the computational complexity and finds one of its possible State Machines cover. The proposed algorithm uses elements of interpretation of Petri nets. The obtained result may not be the best, but it is sufficient for use in rapid prototyping of logic controllers. Found SM-cover will be also used in the development of algorithms for decomposition, and modular synthesis and implementation of parallel logic controllers. Correctness developed heuristic algorithm was verified using Gentzen formal reasoning system.

  18. Synthesis ZnS:Sm thin films from volatile complex compounds

    Science.gov (United States)

    Ivanova, Elena N.; Kovalevskaya, Yu. A.; Bessreguenev, Valentin G.

    2002-11-01

    Deposition and characterization of ZnS, Sm2S3 and ZnS:Sm films are described. The films have been prepared by chemical vapor deposition using new volatile complex compounds, dithiocarbamates of Zn and Sm, as precursors. Characterization includes X-ray diffraction, chemical analysis of the film composition, ellipsometry and spectrophotometry. It has been shown that at relatively low temperatures (about 380 °C) monophase crystalline Sm2S3 films can be fabricated. Doping of ZnS by Sm with dopant concentration up to 2 at. % has been achieved. Effects of Sm doping on structural and optical properties of the film are presented.

  19. Electrochemical preparation of Al–Sm intermetallic compound whisker in LiCl–KCl Eutectic Melts

    International Nuclear Information System (INIS)

    Highlights: • The reduction process of Sm(III) was investigated in LiCl–KCl melt on an aluminum electrode at 773 K. • Al–Sm alloy with different phase structure (Al2Sm and Al3Sm) was prepared by potentiostatic electrolysis on an aluminum electrode with the change of electrolytic potentials and time in LiCl–KCl–SmCl3 melts. • Al − Sm alloy containing whiskers (Al4Sm) was obtained by potentiostatic electrolysis (−2.10 V) on an aluminum electrode for 7 hours with the change of electrolytic temperature and cooling rate in LiCl–KCl–SmCl3 (16.5 wt. %) melts. The results from micro–hardness test and potentiodynamic polarization test show the micro hardness and corrosion property are remarkably improved with the help of Al–Sm intermetallic compound whiskers. - Abstract: This work presents the electrochemical study of Sm(III) on an aluminum electrode in LiCl–KCl melts at 773 K by different electrochemical methods. Three electrochemical signals in cyclic voltammetry, square wave voltammetry, open circuit chronopotentiometry, and cathode polarization curve are attributed to different kinds of Al–Sm intermetallic compounds, Al2Sm, Al3Sm, and Al4Sm, respectively. Al–Sm alloy with different phase structure (Al2Sm and Al3Sm) could be obtained by the potentiostatic electrolysis with the change of electrolytic potentials and time. Al–Sm alloy containing whiskers (Al4Sm) was obtained by potentiostatic electrolysis (−2.10 V) on an aluminum electrode for 7 hours with the change of electrolytic temperature and cooling rate in LiCl–KCl–SmCl3 (16.5 wt. %) melts. The XRD and SEM&EDS were employed to investigate the phase composition and microstructure of Al–Sm alloy. SEM analysis shows that lots of needle−like precipitates formed in Al–Sm alloy, and their ratios of length to diameter are found to be greater than 10 to 1. The TEM and electron diffraction pattern were performed to investigate the crystal structure of the needle

  20. Směsný cement pro speciální účely

    OpenAIRE

    Hrdina, Matěj

    2013-01-01

    Bakalářská práce se v teoretické části zabývá technologií výroby portlandského cementu. Jeho surovinovým složením, mineralogickým složením, teorií vzniku slínkových minerálů při výpalu a jeho možným mísením s jinými surovinami vhodného charakteru. Je uveden přehled speciálních druhů cementů. V experimentální části byl vypracován návrh cementových směsí normativně označovaných jako „Cement pro zdění“. Na cementech byly zkoumány normou požadované vlastnosti v závislosti na množství a druhu použ...

  1. Electrical and thermal characterization of Sm{sup 3+} doped ceria electrolytes synthesized by combustion technique

    Energy Technology Data Exchange (ETDEWEB)

    Mangalaraja, R.V., E-mail: mangal@udec.cl [Department of Materials Engineering, University of Concepcion, Concepcion (Chile); Ananthakumar, S. [Materials and Minerals Division, National Institute for Interdisciplinary Science and Technology (NIIST), CSIR, Trivandrum (India); Paulraj, M. [Department of Physics, University of Concepcion (Chile); Pesenti, H.; Lopez, Marta; Camurri, Carlos P. [Department of Materials Engineering, University of Concepcion, Concepcion (Chile); Barcos, Loreto A.; Avila, Ricardo E. [Department of Nuclear Materials, Chilean Nuclear Energy Commission, Santiago (Chile)

    2012-01-05

    Nanocrystalline samarium doped ceria electrolyte [Ce{sub 0.9}Sm{sub 0.1}O{sub 1.95}] was synthesized by citrate gel combustion technique involving mixtures of cerium nitrate oxidizer (O) and citric acid fuel (F) taken in the ratio of O/F = 1. The as-combusted precursors were calcined at 700 deg. C/2 h to obtain fully crystalline ceria nano particles. It was further made into cylindrical pellets by compaction and sintered at 1200 deg. C with different soaking periods of 2, 4 and 6 h. The sintered ceria was characterized for the microstructures, electrical conductivity, thermal conductivity and thermal diffusivity properties. In addition, the combustion derived ceria powder was also analysed for the crystallinity, BET surface area, particle size and powder morphology. Sintered ceria samples attained nearly 98% of the theoretical density at 1200 deg. C/6 h. The sintered microstructures exhibit dense ceria grains of size less than 500 nm. The electrical conductivity measurements showed the conductivity value of the order of 10{sup -2} S cm{sup -1} at 600 deg. C with activation energy of 0.84 eV between the temperatures 100 and 650 deg. C for ceria samples sintered at 1200 deg. C for 6 h. The room temperature thermal diffusivity and thermal conductivity values were determined as 0.5 x 10{sup -6} m{sup 2} s{sup -1} and 1.2 W m{sup -1} K{sup -1}, respectively.

  2. Using a LaBr3∶Ce scintillator for positron annihilation lifetime spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LIU Jun-Hui; LI Dao-Wu; ZHANG Zhi-Ming; WANG Bao-Yi; ZHANG Tian-Bao; HAO Jia; WEI Long

    2012-01-01

    A LaBr3:Ce scintillator has a high light output (~60000 p.e/MeV) and a short decay constant (<25 ns),which makes it good for time spectrometry.Compared with a BaF2 scintillator,it can bear a much higher count rate,and can be coupled to photomultipliers without using a quartz window.In this work,a positron annihilation lifetime spectrometer (PALS) consisting of two bulks of φ25 mm×25 mm LaBr3:Ce scintillator coupled to two XP20D0 photomultipliers,respectively,was built.A time resolution of FWHM=206 ps was measured for the PALS with a 60Co source at the energy window for 22Na.With this spectrometer,a reasonable lifetime value τ=221±4 ps in a pure Si sample is obtained,which means that the utilization of LaBr3∶Ce as the detector for a PALS is feasible.

  3. BaP (PAH) air quality modelling exercise over Zaragoza (Spain) using an adapted version of WRF-CMAQ model.

    Science.gov (United States)

    San José, Roberto; Pérez, Juan Luis; Callén, María Soledad; López, José Manuel; Mastral, Ana

    2013-12-01

    Benzo(a)pyrene (BaP) is one of the most dangerous PAH due to its high carcinogenic and mutagenic character. Because of this reason, the Directive 2004/107/CE of the European Union establishes a target value of 1 ng/m(3) of BaP in the atmosphere. In this paper, the main aim is to estimate the BaP concentrations in the atmosphere by using last generation of air quality dispersion models with the inclusion of the transport, scavenging and deposition processes for the BaP. The degradation of the particulated BaP by the ozone has been considered. The aerosol-gas partitioning phenomenon in the atmosphere is modelled taking into a count that the concentrations in the gas and the aerosol phases. If the pre-existing organic aerosol concentrations are zero gas/particle equilibrium is established. The model has been validated at local scale with data from a sampling campaign carried out in the area of Zaragoza (Spain) during 12 weeks.

  4. The centroid shift of the 5d levels of Ce sup 3 sup + with respect to the 4f levels in ionic crystals, a theoretical investigation

    CERN Document Server

    Andriessen, J; Eijk, C W E

    2002-01-01

    The centroid shifts of the 5d level of Ce sup 3 sup + in BaF sub 2 , LaAlO sub 3 and LaCl sub 3 have been calculated using the ionic cluster approach. By applying configuration interaction as extension of the basic HF-LCAO approach the dynamical polarization contribution to the centroid shift was calculated. This was found to be only successful if basis sets are used optimized for polarization of the anions.

  5. Studies concerning the preparation of the 153Sm complex with EDTMP (ethylenediaminetetra methylenephosphonic acid) and other 153Sm complexes with other phosphonates, at room temperature

    International Nuclear Information System (INIS)

    This work presents a study on the preparation of the complexes 153Sm - EDTMP, 153Sm - HEDP, 153Sm - NTMP, 153Sm - DTPMP and 153Sm - HDTMP at room temperature. The preparation of the complex 153Sm - HDTMP, under heating (70 - 72 deg C), was also studied. Several factors affecting the 153Sm - EDTMP complexing yields were studied, due to its importance for use in Nuclear Medicine. These factors were: the molar ratio [ligand] / [metal], the ligand concentration and the incubation time of the mixture ligand-metal. The preparation of this complex, in low molar ratios, was also investigated. A study of the 153Sm - EDTMP concerning the 'in vitro' stability, when this complex was prepared in low radioactive concentrations was performed. A study on the temperature influence on its degradation, when this complex was obtained in higher radioactive concentrations, was also performed. The preparation of the complexes 153Sm - HEDP, 153Sm - NTMP, 153Sm - DTPMP and 153Sm - HDTMP was investigated by preparing the complexes in two situations: high molar ratio and ligand concentration and low molar ratio and ligand concentration. The 'in vitro' stability of each complex, obtained in low radioactive concentration was studied. In the specific case of the complex 153Sm - HDTMP, its biological distribution in mice was performed. All the complexes were investigated by high performance liquid chromatography (HPLC) and its complexing yields were determined by other three chromatographic processes: ionic exchange, thin layer chromatography (TLC - SG) and paper chromatography. The chromatographic processes were performed by association with specific radiochemical techniques. This work also presents a comparative study on the chromatograms obtained by thin layer chromatography (TLC - SG) and paper chromatography, when evaluated by the technique of cutting the strips into pieces and the chromatograms performed directly on a radiochromatography. The shape of the chromatograms and Rf values of 153

  6. Electronic structure and magnetic properties of metastable SmCo7 compound

    Institute of Scientific and Technical Information of China (English)

    ZHANG Changwen; LI Hua; DONG Jianmin; WANG Yongjuan; PAN Fengchun; ZHANG Jian; GUO Yongquan; LI Wei

    2005-01-01

    The electronic density of states, spin-splittings and atomic magnetic moments of SmCo7 compound have been studied using spin-polarized MS-X( method. The results show that a few of electrons are transferred to Sm(5d0) orbital because of orbital hybridization between Sm and Co atoms in the compound. The exchange interactions between 3d and 5d electrons lead to the magnetic coupling between Sm and Co, and therefore, result in the long-range ferromagnetic order inside the SmCo7 compound. There are negative exchange couplings occurring at some levels, which weakens the strength of average coupling around Co lattice. So, the Curie temperature and Co-moment of SmCo7 decrease distinctly compared with pure Co. Compared with SmCo5 compound, the disordered substitution of Co-Co "dumbbell-atom" pairs for Sm changes the local environment of Co lattice, which makes the 2e site bear negative magnetic moment. The strength of hybridization near Fermi level weakens and the free energy of the compound increases obviously. Thus, SmCo7 is a metastable compound at room temperature. Considering the localization of 4f electrons and a few of 5d electrons arising from the orbital hybridization, the magnetic moment of Sm atom will be 1.61μB in SmCo7 compound, which is in agreement with the experimental values of Sm3+ ion- moment and Sm atom-moment in metals.

  7. Effects of Sm on the grain refinement, microstructures and mechanical properties of AZ31 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ming [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Hu, Xiaoyu [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Peng, Liming, E-mail: plm616@sjtu.edu.cn [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Fu, Penghuai [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Peng, Yinghong [School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2015-01-03

    The effects of samarium (Sm) on the grain refinement, microstructures and mechanical properties of as-cast AZ31 (Mg–3Al–1Zn–0.3Mn) magnesium (Mg) alloy have been investigated. Very serious grain coarsening happens when Sm content is between 0.16% and 1.18%. This is due to both the reactions between Al and Sm which reduce the constitutional undercooling effect and the lack of Al{sub 2}Sm heterogeneous nuclei. However, excellent grain refinement effect is achieved at Sm content above 2.17%, which is because the in-situ formed Al{sub 2}Sm particles significantly promote heterogeneous nucleation. The main phases in AZ31–xSm alloys include α-Mg, β-Mg{sub 17}Al{sub 12}, Al{sub 11}Sm{sub 3} and Al{sub 2}Sm. The Mg{sub 17}Al{sub 12} phase is gradually suppressed by the increase in Sm content, and the Al{sub 2}Sm is present at a higher Sm content. Because of grain refinement strengthening and secondary phase strengthening effects, the room temperature tensile property of AZ31–3.13Sm alloy has the optimal value of YS78.7MPa–UTS216.7MPa-EL13.6%.

  8. The formin-homology protein SmDia interacts with the Src kinase SmTK and the GTPase SmRho1 in the gonads of Schistosoma mansoni.

    Directory of Open Access Journals (Sweden)

    Thomas Quack

    Full Text Available BACKGROUND: Schistosomiasis (bilharzia is a parasitic disease of worldwide significance affecting human and animals. As schistosome eggs are responsible for pathogenesis, the understanding of processes controlling gonad development might open new perspectives for intervention. The Src-like tyrosine-kinase SmTK3 of Schistosoma mansoni is expressed in the gonads, and its pharmacological inhibition reduces mitogenic activity and egg production in paired females in vitro. Since Src kinases are important signal transduction proteins it is of interest to unravel the signaling cascades SmTK3 is involved in to understand its cellular role in the gonads. METHODOLOGY AND RESULTS: Towards this end we established and screened a yeast two-hybrid (Y2H cDNA library of adult S. mansoni with a bait construct encoding the SH3 (src homology domain and unique site of SmTK3. Among the binding partners found was a diaphanous homolog (SmDia, which was characterized further. SmDia is a single-copy gene transcribed throughout development with a bias towards male transcription. Its deduced amino acid sequence reveals all diaphanous-characteristic functional domains. Binding studies with truncated SmDia clones identified SmTK3 interaction sites demonstrating that maximal binding efficiency depends on the N-terminal part of the FH1 (formin homology domain and the inter-domain region of SmDia located upstream of FH1 in combination with the unique site and the SH3 domain of SmTK3, respectively. SmDia also directly interacted with the GTPase SmRho1 of S. mansoni. In situ hybridization experiments finally demonstrated that SmDia, SmRho1, and SmTK3 are transcribed in the gonads of both genders. CONCLUSION: These data provide first evidence for the existence of two cooperating pathways involving Rho and Src that bridge at SmDia probably organizing cytoskeletal events in the reproductive organs of a parasite, and beyond that in gonads of eukaryotes. Furthermore, the FH1 and inter

  9. Návrh směsi typu asfaltový beton a stanovení odolnosti proti tvorbě trvalých deformací

    OpenAIRE

    Němec, Jan

    2014-01-01

    Tato Bakalářská práce se zabývá problematikou asfaltové směsi typu ACO 11+ a jejím využitím do konstrukce vozovek. Byly vypracovány zkoušky vstupních materiálů. Vstupními materiály je kamenivo a pojivo. Na základě výsledků vstupních zkoušek byla navržena nová asfaltová směs. Tato asfaltová směs byla zkoušena na odolnost proti vzniku trvalých deformací. Na základě výsledků této zkoušky se uvažuje nad změnou národní přílohy normy ČSN EN 13 108-1 Asfaltový beton. Z hlediska porovnání výsledků js...

  10. Mercury speciation by CE: an update.

    Science.gov (United States)

    Kubán, Petr; Pelcová, Pavlína; Margetínová, Jana; Kubán, Vlastimil

    2009-01-01

    This review provides an update on mercury speciation by CE. It includes a brief discussion on physicochemical properties, toxicity and transformation pathways of mercury species (i.e. methyl-, ethyl-, phenyl- and inorganic mercury) and outlines recent trends in Hg speciation by CE. CE is presented as a complementary technique to chromatographic separation techniques, especially in cases when speed, high efficiency and low sample volumes are required. The development of suitable sample preconcentration/isolation (sample stacking, ion exchange, liquid-liquid-liquid extraction, dual-cloud point extraction) to achieve low LODs for analysis of trace concentrations of mercury species in real samples is emphasized. Hyphenation of CE to element specific detectors (i.e. electrothermal atomic absorption spectrometry, atomic fluorescence spectrometry, inductively coupled plasma-optical emission spectrometry, inductively coupled plasma-mass spectrometry) is discussed as well as a potential of CE in interaction studies that may provide useful information on interaction of various Hg species with selected bio-macromolecules.

  11. Direct digital control of the WWR-SM research reactor

    International Nuclear Information System (INIS)

    The report describes the computerized control system of a 5 MW WWR-SM research reactor. The system is realized as a multilayer decision hierarchy where simple subsystems control the power and the outlet temperature of the reactor under the supervision of a self-organization layer. The structure of the program system and the hardware configuration are presented. (author)

  12. ACS after SM4: New Life for an Old Workhorse

    Science.gov (United States)

    Golimowski, David; Anderson, Jay; Armstrong, Amber; Arslanian, Steve; Bedin, Luigi; Bohlin, Ralph; Boyce, Kevin; Chapman, George; Cheng, Edward; Chiaberge, Marco; Cox, Colin; Desiardins, Tyler; Dye, Darryl; Ellis, Tracy; Ferguson, Brian; Fruchter, Andrew; Grogin, Norman; Lim, Pey Lian; Loose, Markus; Lucas, Ray; Lupie, Olivia; Mack, Jennifer; Maybhate, Aparna; Mil, Kathleen; Mutchler, Max; Ricardo, Raphael; Scott, Barbara; Serrano, Beverly; Sirianni, Marco; Smith, Linda; Suchkov, Anatoly A.; Waczynski, Augustyn; Welty, Alan; Wheeler, Thomas; Wilson, Erin

    2010-07-01

    The ACS CCD Electronics Box Replacement (CEB-R) installed during SM4 features a Teledyne SIDECAR ASIC that permits optimization of the WFC via adjustment of CCD clock voltages, bias voltages, and pixel transmission timing. An on-orbit campaign to optimize the performance of the WFC was undertaken at the start of the SMOV period. Initial tests with pre-SM4 default voltages and timing patterns showed that WFC's performance matches or exceeds its pre-failure levels, notwithstanding the expected increases in dark current and hot pixels and the decline in charge-transfer efficiency due to prolonged exposure to HST's radiation environment. One WFC CCD exhibited anomalous behavior when operated with nondefault settings of its reset drain voltage. Consequently, the optimization campaign was truncated after two iterations, and ACS science operations commenced with the pre-SM4 default configuration. Several artifacts attributed to the CEB-R appear in post-SM4 WFC images: large-scale but stable bias gradients, low-level but temporally variable horizontal stripes, a signal-dependent bias shift, and amplifier crosstalk. STScI has developed algorithms for the correction or mitigation of these electronic artifacts as well as for the restoration of images affected by continuously degrading CTE. Standalone correction packages are now or will soon be publicly available. These packages will be incorporated into the calacs package of the OPUS data pipeline by September 2011.

  13. Searches for Beyond SM Higgs Boson at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Safonov, A.; /Texas A-M

    2006-05-01

    In the following, the authors describe preliminary results of searches for non-SM higgs bosons at the CDF and D0 experiments. Both experiments use data obtained in p{bar p} collisions at the Tevatron at {radical}s = 1.96 TeV.

  14. SM4AM: A Semantic Metamodel for Analytical Metadata

    DEFF Research Database (Denmark)

    Varga, Jovan; Romero, Oscar; Pedersen, Torben Bach;

    2014-01-01

    . We present SM4AM, a Semantic Metamodel for Analytical Metadata created as an RDF formalization of the Analytical Metadata artifacts needed for user assistance exploitation purposes in next generation BI systems. We consider the Linked Data initiative and its relevance for user assistance...

  15. Metastable magnetic polaron effects in SmS

    International Nuclear Information System (INIS)

    The resistivity, Hall effect and magnetoresistance of nominally stoichiometric black phase SmS single crystals were measured at pressures up to 4 kbar, for temperatures ranging from 1.2 to 300K. Metastable effects in the free electron population were observed below 20K. These effects are explained by a bound magnetic polaron concept

  16. Plantens små kraftværker

    DEFF Research Database (Denmark)

    Møller, I.M.; Bykova, N.V.

    2001-01-01

    mitokondrien. Mitokondrier er plantecellernes små kraftværker, som forsyner plantecellen med energi i form af ATP (adenosintriphosphat) og byggesten til syntese af cellens bestanddele. For at forstårespirationen må vi have en grundig forståelse af mitokondrien og dens proteiner. Den viden kan igen føre til, at...

  17. Structure and physical properties of single crystal PrCr{sub 2}Al{sub 20} and CeM{sub 2}Al{sub 20} (M=V, Cr): A comparison of compounds adopting the CeCr{sub 2}Al{sub 20} structure type

    Energy Technology Data Exchange (ETDEWEB)

    Kangas, Michael J.; Schmitt, Devin C.; Sakai, Akito; Nakatsuji, Satoru [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Chan, Julia Y., E-mail: jchan@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan)

    2012-12-15

    Crystal growth and full structure determination of compounds adopting the CeCr{sub 2}Al{sub 20} structure type, LnTi{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), LnV{sub 2}Al{sub 20} (Ln=La-Pr, and Sm), and LnCr{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), are reported. Resistivity, magnetic susceptibility, and heat capacity of flux grown single crystals of the nonmagnetic CeM{sub 2}Al{sub 20} (Ln=Ce, Yb; M=Ti, V) compounds are compared to PrCr{sub 2}Al{sub 20}. Of particular interest is PrCr{sub 2}Al{sub 20} which does not show any phase transition down to the lowest temperature of the measurement (400 mK in resistivity measurement and 1.8 K for magnetic susceptibility measurements) and exhibits Kondo behavior at low temperatures. - Graphical abstract: Crystal structure of SmV{sub 2}Al{sub 20} showing the interpenetrating diamond-like samarium network and pyrochlore-like vanadium network. Highlights: Black-Right-Pointing-Pointer Single crystals of LnM{sub 2}Al{sub 20} were grown from a molten aluminum flux. Black-Right-Pointing-Pointer Magnetic, electrical, and specific heat of single crystal LnM{sub 2}Al{sub 20} are presented. Black-Right-Pointing-Pointer PrCr{sub 2}Al{sub 20} exhibits evidence of Kondo effect.

  18. Synthesis of Dimethyl Carbonate from Ethylene Carbonate and Methanol Over Nano-Catalysts Supported on CeO2-MgO.

    Science.gov (United States)

    Jun, Jin Oh; Lee, Joongwon; Kang, Ki Hyuk; Song, In Kyu

    2015-10-01

    A series of CeO2(X)-MgO(1-X) (X = 0, 0.25, 0.5, 0.75, and 1.0) nano-catalysts were prepared by a co-precipitation method for use in the synthesis of dimethyl carbonate from ethylene carbonate and methanol. Among the CeO2(X)-MgO(1-X) catalysts, CeO2(0.25)-MgO(0.75) nano-catalyst showed the best catalytic performance. Alkali and alkaline earth metal oxides (MO = Li2O, K2O, Cs2O, SrO, and BaO) were then supported on CeO2(0.25)-MgO(0.75) by an incipient wetness impregnation method with an aim of improving the catalytic performance of CeO2(0.25)-MgO(0.75). Basicity of the catalysts was determined by CO2-TPD experiments in order to elucidate the effect of basicity on the catalytic performance. The correlation between catalytic performance and basicity showed that basicity played an important role in the reaction. Yield for dimethyl carbonate increased with increasing basicity of the catalysts. Among the catalysts tested, Li2O/CeO2(0.25)-MgO(0.75) nano-catalyst with the largest basicity showed the best catalytic performance in the synthesis of dimethyl carbonate. PMID:26726512

  19. Investigation of spectroscopy and the dual energy transfer mechanisms of Sm3+-doped telluroborate glasses

    Science.gov (United States)

    Van Do, Phan; Tuyen, Vu Phi; Quang, Vu Xuan; Hung, Le Xuan; Thanh, Luong Duy; Ngoc, Tran; Van Tam, Ngo; Huy, Bui The

    2016-05-01

    The absorption, luminescence, Raman spectra and lifetimes of Sm-doped alkali telluroborate glasses (TB glasses) TB:Sm3+ have been investigated. The dual energy transfers including energy transfer between Sm3+ - Sm3+ pairs and Sm3+ - non-bridging oxygen (NBO) intrinsic defects were investigated. The concentration quenching of luminescence intensity was explained by the non-radiative energy transfer between the Sm3+ ions through the cross-relaxation mechanism. The decay curves are single exponentials with low concentrations (lower 0.10 mol%) and become non-exponentials at higher concentrations. The non-exponential decay curves are fitted to the Inokuti and Hirayama model to give the energy transfer parameters between Sm3+ ions. The dominant interaction mechanism for energy transfer process is dipole-dipole interaction. The energy transfer induced Sm3+ photoluminescence enhancement in tellurite glass was experimentally studied and confirmed.

  20. Orange and reddish-orange light emitting phosphors: Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Meza-Rocha, A.N., E-mail: ameza@fis.cinvestav.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico); Speghini, A. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); IFAC CNR, Nello Carrara Institute of Applied Physics, MDF Lab, I-50019 Sesto Fiorentino, FI (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Caldiño, U. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico)

    2015-11-15

    A spectroscopy study of Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses is performed through photoluminescence spectra and decay time profile measurements. Under Sm{sup 3+} excitation at 344 nm, the Sm{sup 3+} singly doped glass shows an orange global emission with x=0.579 and y=0.414 CIE1931 chromaticity coordinates, whereas the Sm{sup 3+}/Eu{sup 3+} co-doped sample exhibits orange overall emissions (x=0.581 and y=0.398, and x=0.595 and y=0.387) and reddish-orange overall emission (x=0.634 and y=0.355) upon excitations at 344, 360 and 393 nm, respectively. Such luminescence from the co-doped sample is originated by the simultaneous emission of Sm{sup 3+} and Eu{sup 3+}. Under Sm{sup 3+} excitation at 344 and 360 nm, the Eu{sup 3+} emission is sensitized and enhanced by Sm{sup 3+} through a non-radiative energy transfer process. The non-radiative nature was inferred from the shortening of the Sm{sup 3+} lifetime observed in the Sm{sup 3+}/Eu{sup 3+} co-doped sample. An analysis of the Sm{sup 3+} emission decay time profiles using the Inokuti–Hirayama model suggests that an electric quadrupole–quadrupole interaction into Sm–Eu clusters might dominate the energy transfer process, with an efficiency of 0.17. - Highlights: • Zinc phosphate glasses are optically activated with Sm{sup 3+}/Eu{sup 3+} (ZPOSmEu). • Non-radiative energy transfer Sm{sup 3+}→Eu{sup 3+} takes place in ZPOSmEu. • ZPOSmEu overall emission can be modulated with the excitation wavelength. • ZPOSmEu might be useful as orange/reddish-orange phosphor for UV-white LEDs.

  1. Anomalous magnetic moment at Ba in Au

    Science.gov (United States)

    Bhati, A. K.; Kaur, J.; Bansal, N.; Negi, D.; Kumar, R.; Bhowmik, R. K.; Kumar, V.; Dey, C. C.

    2015-04-01

    The Time differential perturbed angular distribution (TDPAD) technique is employed to measure the local susceptibility at the recoil implanted Ba ions in Au following the nuclear reaction 120Sn(12C, 3nγ)129Ba. We have observed first time the local paramagnetic susceptibility of 5.26(18) at Ba ions comparable to 4f-ions in any non-ferromagnetic metal at room temperature which seems to be related to the electronic s-d and s-f transfer at positive lattice pressure.

  2. Quasiparticle Band Structure of BaS

    Institute of Scientific and Technical Information of China (English)

    LU Tie-Yu; CHEN De-Yan; HUANG Mei-Chun

    2006-01-01

    @@ We calculate the band structure of BaS using the local density approximation and the GW approximation (GWA),i.e. in combination of the Green function G and the screened Coulomb interaction W. The Ba 4d states are treated as valence states. We find that BaS is a direct band-gap semiconductor. The result shows that the GWA band gap (Eg-Gw = 3.921 eV) agrees excellently with the experimental result (Eg-EXPT = 3.88 eV or 3.9eV).

  3. AMiBA, XMM, and Cluster Surveys

    OpenAIRE

    Liang, Haida

    2001-01-01

    The Array for Microwave Background Anisotropy (AMiBA) is an interferometric array of 19 dishes co-mounted on a steerable platform and operating at 95GHz. One of the main scientific aims of AMiBA is to conduct cluster surveys using the Sunyaev-Zel'dovich (SZ) effect. Here we explore the potential of AMiBA as a tailor-made SZ instrument for the study of cluster physics and cosmology via cluster surveys out to the epoch of cluster formation. In particular, we explore the potential of combining A...

  4. REE chemistry and Sm-Nd systematics of late Archean weathering profiles in the Fortescue Group, Western Australia

    Science.gov (United States)

    MacFarlane, A. W.; Danielson, A.; Holland, H. D.; Jacobsen, S. B.

    1994-01-01

    Two weathering profiles, each consisting of an upper, sericite-rich zone and a lower, chlorite-rich zone, are preserved between flows of the Mt. Roe Basalt in the Fortescue Group, Hamersley Basin, Western Australia. REE concentrations in samples from these two profiles, which originally developed ca 2,760 Ma, show large variations depending on stratigraphic position. LREE abundances and (La/Yb)N are greatest at depths of 3-6 m below the paleosurface of the Mt. Roe #1 profile and are somewhat lower in samples above this level. The LREEs reach concentrations 6-9 times greater than in the underlying basalt, and thus appear to have been mobilized downward in the paleosol and concentrated in its middle part. LREE concentrations in the #2 profile show a similar distribution but with a sharp increase in all REE concentrations within 50 cm of the paleosurface. The distinction between the REE profiles in the two paleosols may be related to the difference in the overlying material. The #1 paleosol is overlain by a few meters of sediments and then by basalt, whereas the #2 paleosol is directly overlain by basalt. The LREEs appear to have been mobilized both during chemical weathering of the parental basalt and during later lower-greenschist-facies metamorphism and metasomatism of the paleosols. Remobilization of the REEs during the regional metamorphism of the Fortescue Group is confirmed by a whole-rock Sm-Nd reference isochron of Mt. Roe #1 samples with an age of 2,151 +/- 360 Ma. Variable initial 143Nd/144Nd values of unweathered basalt samples which may represent the paleosol protolith prevents a confident determination of the magnitude of LREE mobility. Both the initial mobilization of the REEs during weathering and the metasomatic remobilization appear to have taken place under redox conditions where Ce was present dominantly as Ce3+, because Ce anomalies are not developed within the sericite zone samples regardless of concentration. Europium anomalies in the

  5. New approaches in sensitive chiral CE.

    Science.gov (United States)

    Sánchez-Hernández, Laura; Guijarro-Diez, Miguel; Marina, María Luisa; Crego, Antonio L

    2014-01-01

    CE has shown to have a big potential for chiral separations, with advantages such as high efficiency, high resolution, and low sample and reagents consumption. Nevertheless, when UV detection is employed, CE has some drawbacks, especially the low sensitivity obtained due to the short optical path length. Notwithstanding, sensitivity improvements can be achieved when different approaches are employed, such as sample treatment strategies (off-line or on-line), in-capillary sample preconcentration techniques, and/or alternative detection systems to UV-Vis (such as fluorescence, conductimetry, electrochemiluminiscence, MS, etc.). This article reviews the most recent methodological and instrumental advances reported from June 2011 to May 2013 for enhancing the sensitivity in chiral analysis by CE. The sensitivity achieved for the enantioseparated analytes and the applications carried out using the developed methodologies are also summarized.

  6. Thermoluminescence characteristics of Sm3+ doped NaYF4 crystals

    Indian Academy of Sciences (India)

    M V Ramana Reddy; Ch Gopal Reddy; K Narasimha Reddy

    2007-02-01

    Thermoluminescence (TL) characteristics of NaYF4 crystals doped with Sm3+ have been studied after -ray irradiation. Dependence of luminescence efficiency on Sm3+ concentration and radiation dose has been measured and possible applications of NaYF4 : Sm3+ as a novel phosphor for TL dosimetry have been investigated. The efficiency of 0.3 mole% Sm3+ doped NaYF4 crystal has been found to be maximum and comparable with commercial thermoluminescence dosimetric (TLD) materials.

  7. Recent advances in the chemistry of SmI(2)-H(2)O.

    Science.gov (United States)

    Sautier, Brice; Procter, David J

    2012-01-01

    Recent work from our laboratories has shown SmI(2)-H(2)O to be a versatile, readily-accessible and non-toxic reductant that is more powerful than SmI(2). This review describes the reduction of functional groups that were previously thought to lie beyond the reach of SmI(2) and complexity-generating cyclisations and cyclisation cascades triggered by the reduction of the ester carbonyl group with SmI(2)-H(2)O.

  8. Transmission electron microscopy study on defect structure of SmS monocrystals

    International Nuclear Information System (INIS)

    Monocrystalline SmS samples were studied by the method of transmission electron microscopy. A large quantity of Sm3S4 depositions of micron size as shown to be present as a rule in SmS monocrystals grown nowdays. Colonies of precipitates and full dislocation loops were revealed in some samples. Obtained are data on the structure of metal layer appearing on the surface of SmS crystals at its mechanical polishing

  9. Syntheses, crystal structure, and electronic properties of the five ABaMQ4 compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4

    Science.gov (United States)

    Mesbah, Adel; Prakash, Jai; Rocca, Dario; Lebègue, Sébastien; Beard, Jessica C.; Lewis, Benjamin A.; Ibers, James A.

    2016-01-01

    Five new compounds belonging to the ABaMQ4 family were synthesized by solid-state chemistry at 1123 K. The compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4 are isostructural and have the TlEuPS4 structure type. They crystallize in space group D162h - Pnma of the orthorhombic system. Their structure consists isolated MQ4 tetrahedra separated by A and Ba atoms to form a salt-like structure. Density Functional Theory (DFT) calculations of the electronic structures with the use of the HSE functional suggest that the compounds are semiconductors with calculated band gaps of 3.3 eV (RbBaPS4), 3.4 eV (CsBaPS4), 2.3 eV (CsBaVS4), and 1.6 eV (RbBaVSe4).

  10. Electrochemical Oxidation of BaFeO2.5 to BaFeO3

    International Nuclear Information System (INIS)

    Defect perovskite-type BaFeO2.5 was oxidized to BaFeO3 by an electrochemical method in an alkaline aqueous electrolyte at 25 °C. With increase in the charge transfer q (electrons/formula unit), BaFeOz showed monoclinic (at nearly q = 0), rhombohedral (at around q = 0.34), pseudo-cubic (at 0.78 ≤ q ≤ 0.89), and true cubic (at q ≥ 0.89) structures. While an oxygen evolution reaction (OER) started at ca. q = 0.80, the oxidation of BaFeOz could concurrently be continued with the OER and BaFeO3 was obtained at q = 1.2. Further, the chemical potential of oxygen in BaFeOz could be estimated in the range of 2.5 ≤ z ≤ 2.87 without OER

  11. Superconductivity in CeCo2 nanoparticles

    International Nuclear Information System (INIS)

    Both Ce and Co are essentially nonmagnetic in Pauli-paramagnetic CeCo2, which undergoes a superconducting transition near 1K. When made into 58-A nanoparticles, the compound becomes paramagnetic. Meanwhile, based on heat capacity measurements, the nanoparticles remain to be nonsuperconducting down to 0.4K but exhibit a low-temperature Kondo anomaly with C/T∼ 350mJ/molK2 at 0.4K. Such intriguing effects are consequences of the competition between superconducting gap and electronic spectrum's mean level spacing

  12. Laser altimeter of CE-1 payloads system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The design and operation of the Laser Altimeter of CE-1 Payloads System are presented in this paper.The paper includes the design of the system and spacecraft-level laser,the description of the emitting-system and receiving system,and the testing of the laser altimeter.The CE-1 laser altimeter is the first Chinese deep-space probe using a laser.It has one beam and operates at 1 Hz,with a nominal accuracy of 5 m.The laser altimeter has operated successfully in lunar orbit since November 28,2007.It has obtained 9120 thousand data values about the lunar altitude.

  13. Metamagnetism in Ce(Ga,Al)2

    Indian Academy of Sciences (India)

    K G Suresh; S Radha; A K Nigam

    2002-05-01

    Effect of Al substitution on the magnetic properties of Ce(Ga1-Al)2 ( = 0, 0.1 and 0.5) system has been studied. The magnetic state of CeGa2 is found to be FM with a C of 8 K, whereas the compounds with =0.1 and 0.5 are AFM and possess N of about 9 K. These two compounds undergo metamagnetic transition and the critical fields are about 1.2 T and 0.5 T, respectively at 2 K. These variations are explained on the basis of helical spin structure in these compounds.

  14. Research on the magnetic material of Sm-Fe matrix nitrides

    Institute of Scientific and Technical Information of China (English)

    CUI Chunxiang; SUN Jibing; ZHANG Ying; WANG Ru; LI Lin; LIANG Zhimei

    2005-01-01

    In this paper, the types of Sm-Fe matrix compounds and their correlations are introduced, and progress of research on the magnetic materials of Sm-Fe matrix nitrides is also reviewed. Possible research trends of future permanent magnetic materials of SmFe matrix nitrides are briefly predicted.

  15. Neutron scattering from -Ce at epithermal neutron energies

    Indian Academy of Sciences (India)

    A P Murani

    2008-10-01

    Neutron scattering data, using neutrons of incident energies as high as 2 eV, on -Ce and -Ce-like systems such as CeRh2, CeNi2, CeFe24, CeRu2, and many others that point clearly to the substantially localized 4f electronic state in these systems are reviewed. The present interpretation is contrary to the widely held view that the 4f electrons in these systems form a narrow itinerant electron 4f band.

  16. A new seeding technique for the reliable fabrication of large, SmBCO single grains containing silver using top seeded melt growth

    Science.gov (United States)

    Shi, Y.-H.; Dennis, A. R.; Cardwell, D. A.

    2015-03-01

    Silver (Ag) is an established additive for improving the mechanical properties of single grain, (RE)Ba2Cu3O7-δ [(RE)BCO, RE = Sm, Gd and Y] bulk superconductors. The presence of Ag in the (RE)BCO bulk composition, however, typically reduces the melting temperature of the single crystal seed in the top seeded melt growth (TSMG) process, which complicates significantly the controlled nucleation and subsequent epitaxial growth of a single grain, which is essential for high field engineering applications. The reduced reliability of the seeding process in the presence of Ag is particularly acute for the SmBCO system, since the melting temperature of SmBCO is very close to that of the generic NdBCO(MgO) seed. SmBCO has a high superconducting transition temperature, Tc, and exhibits the most pronounced ‘peak’ effect at higher magnetic field of all materials in the family of (RE)BCO bulk superconductors and, therefore, has the greatest potential for use in practical applications (compared to GdBCO and YBCO, in particular). Development of an effective seeding process, therefore, is one of the major challenges of the TSMG process for the growth of large, high quantity single grain superconductors. In this paper, we report a novel technique that involves introducing a buffer layer between the seed crystal and the precursor pellet, primarily to inhibit the diffusion of Ag from the green body to the seed during melt processing in order to prevent the melting of the seed. The success rate of the seeding process using this technique is 100% for relatively small batches of samples. The superconducting properties, critical temperature, Tc, critical current density, Jc and trapped fields, of the single grains fabricated using the buffers are reported and the microstructures in the vicinity of the buffer of single grains fabricated by the modified technique are analysed to understand further the effects of buffers on the growth process of these technologically important

  17. Influence of cerium doping on the dielectric relaxation of Sr{sub 0.75}Ba{sub 0.25}Nb{sub 2}O{sub 6} single crystal grown by the double crucible Stepanov technique

    Energy Technology Data Exchange (ETDEWEB)

    Bhaumik, Indranil, E-mail: neel@rrcat.gov.in [Crystal Growth Laboratory, LMDDD, Raja Ramanna Centre for Advanced Technology, Indore (India); Ganesamoorthy, S. [XS and CGS, CMPD, MSG, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Bhatt, R. [Crystal Growth Laboratory, LMDDD, Raja Ramanna Centre for Advanced Technology, Indore (India); Subramanian, N. [XS and CGS, CMPD, MSG, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Karnal, A.K.; Gupta, P.K. [Crystal Growth Laboratory, LMDDD, Raja Ramanna Centre for Advanced Technology, Indore (India); Takekawa, S.; Kitamura, K. [Polar Domain Engineering Group, NIMS, Namiki, Tsukuba (Japan)

    2015-02-05

    Highlights: • Incorporation of Ce in the lattice reduces dielectric maxima in Sr{sub 0.75}Ba{sub 0.25}Nb{sub 2}O{sub 6}. • It increases degree of diffusiveness and lowers the temperature of dielectric maxima. • These are due to introduction of addition random field via created point defects. • Both of the crystals undergo non-debye type relaxation. • VF fitting revealed that attempt frequency reduced by one order on Ce doping. - Abstract: The effect of Ce doping on the dielectric relaxation in Sr{sub 0.75}Ba{sub 0.25}Nb{sub 2}O{sub 6} single crystal grown by double crucible Stepanov technique has been investigated. It has been observed that the incorporation of Ce ion in the lattice reduces the dielectric maxima. It further increases the degree of diffusiveness and lowers the temperature of dielectric maxima as a result of the introduction of additional random field via created point defects. Both the undoped and Ce doped crystals undergo a non-debye type relaxation. Vogel–Fulcher fitting reveals that the attempt frequency reduced by one order of magnitude on Ce doping.

  18. The DIRC detector at BaBar

    International Nuclear Information System (INIS)

    A dedicated particle identification system based on the Detection of Internally Reflected Cherenkov (DIRC) light will be used in the BaBar detector. We provide an overview of the DIRC concept, design, and expected performance of the production device and a status report on its construction and commissioning. The DIRC is expected to be operating in the BaBar detector on beam line at the PEP-II B Factory in late spring 1999

  19. AMiBA First SZ Measurements

    Science.gov (United States)

    Lin, K.-Y.; Wu, J.-H. P.; Umetsu, K.; Kock, P.; Liu, G.-C.; Nishioka, H.; Huang, C.-W.; Liao, Y.-W.; Wang, F.-C.; Ho, P.

    2008-10-01

    Y.T.Lee Array for Microwave Background Anisotropy (AMiBA) is an array utilizing the 90GHz band to measure the CMB power spectrum and the Sunyaev-Zeldovich effect of galaxy clusters. The first stage with seven antennae has been completed, and the second stage with thirteen antennae is being constructed. Using the seven-element array, AMiBA has performed observations on six massive galaxy clusters at redshifts 0.09 - 0.32 during 2007.

  20. The AMiBA Hexapod Telescope Mount

    OpenAIRE

    Koch, Patrick M.; Kesteven, Michael; Nishioka, Hiroaki; Jiang, Homin; Lin, Kai-Yang; Umetsu, Keiichi; Huang, Yau-De; Raffin, Philippe; Chen, Ke-Jung; Ibanez-Romano, Fabiola; Chereau, Guillaume; Huang, Chih-Wei Locutus; Chen, Ming-Tang; Ho, Paul T. P.; Pausch, Konrad

    2009-01-01

    AMiBA is the largest hexapod astronomical telescope in current operation. We present a description of this novel hexapod mount with its main mechanical components -- the support cone, universal joints, jack screws, and platform -- and outline the control system with the pointing model and the operating modes that are supported. The AMiBA hexapod mount performance is verified based on optical pointing tests and platform photogrammetry measurements. The photogrammetry results show that the defo...