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Sample records for activated solid-state synthesis

  1. Effect of mechanical activation on cordierite synthesis through solid-state sintering method

    S K Nath; Sanjay Kumar; Rakesh Kumar

    2014-10-01

    Synthesis of cordierite (5SiO2.2MgO.2Al2O3) has attracted special attention from researchers for its special characteristics. Most common method of cordierite preparation is solid-state reaction using source of alumina, silica and magnesia, which requires temperature of 1350 °C or above. This study deals with the effect of mechanical activation on cordierite synthesis at lower temperature. Talc, kaolinite clay and alumina powder were taken as precursor materials and the batches were formulated on the basis of stoichometric cordierite formation. Particle size distribution (PSD) was measured to get the distribution pattern of milled powder. Pellets were prepared by compaction of dried milled powders and fired at 1200 °C temperature. X-ray diffraction (XRD) technique was used to characterize crystalline phases. Microstructural analysis was done under scanning electron microscope (SEM). It was observed that properties were improved with milling time. Dense and uniform microstructures were formed when samples were milled for 45 and 60 min.

  2. Facile solid state synthesis of ZnO hexagonal nanogranules with excellent photocatalytic activity

    Pudukudy, Manoj, E-mail: manojpudukudy@gmail.com [Fuel Cell Institute, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia); Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor (Malaysia); Yaakob, Zahira, E-mail: zahirayaakob65@gmail.com [Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor (Malaysia)

    2014-02-15

    In this article, ZnO nanogranules were synthesised rapidly by the thorough solid state mixing of nitrate precursor with citric acid followed by aging and calcination at two different temperatures of 400 °C and 600 °C. Here, citric acid played a superior role in the development of porous ZnO nanostructures. The ZnO nanogranules obtained in this way were characterised by different techniques. X-ray diffraction patterns indicated a hexagonal wurtzite structure of ZnO with high crystallinity and nanocrystalline size. Scanning and transmission electron microscopy images indicated the uniformly well separated hexagonal morphology of the ZnO nanoparticles, with granular shape. BET surface area-porosity analysis confirmed the presence of a mesoporous network in both samples, with high surface area and a monomodal pore size distribution. Room temperature Photoluminescence spectra of the samples exhibited characteristic blue and green emission bands in accordance with the calcination temperature. The photocatalytic performance of the ZnO nanogranules was studied using methylene blue degradation and found that the ZnO prepared at 400 °C exhibited higher photocatalytic activity due to its high surface area and more oxygen vacancies. High concentrations of several hazardous dye pollutants were effectively degraded, when the solution was passed over 50 mg of ZnO nanogranules under UV-light illumination.

  3. Mechanically activated solid-state synthesis of hafnium carbide and hafnium nitride nanoparticles

    Nanocrystalline hafnium nitrides and hafnium carbides are synthesized, from powder mixtures based on partially hydrated hafnium tetrachloride, ph-HfCl4, and on magnesium, by a three-step process, namely a short mechanical activation step followed by a brief annealing step and a leaching step. Grinding of ph-HfCl4 + Mg leads to the formation of hafnium hydrides which decompose upon annealing in argon to give first metallic hafnium and then HfO2 at higher temperatures. Annealing of such ground ph-HfCl4 + Mg blends in flowing nitrogen yields HfN nanoparticles (average size between 10 and 30 nm). HfC carbides are directly mechanosynthesized from ph-HfCl4 + Mg + C powder mixtures. A subsequent heat treatment in flowing argon allows to better crystallize the grains of HfC (average size around 100 nm) and to decompose the intermediate products. The reaction mechanisms are discussed from results of thermogravimetric analyses and from infrared spectra of ph-HfCl4 + Mg based powder mixtures processed in various ways

  4. Solid-State Synthesis, Characterization, and Biological Activity of the Bioinorganic Complex of Aspartic Acid and Arsenic Triiodide

    Guo-Qing Zhong

    2013-01-01

    Full Text Available The bioinorganic complex of aspartic acid and arsenic triiodide was synthesized by a solid-state reaction at room temperature. The formula of the complex is AsI3[HOOCCH2CH(NH2COOH]2.5. The crystal structure of the complex belongs to monoclinic system with lattice parameters: a=1.0019 nm, b=1.5118 nm, c=2.1971 nm, and β=100.28°. The infrared spectra can demonstrate the complex formation between the arsenic ion and aspartic acid, and the complex may be a dimer with bridge structure. The result of primary biological test indicates that the complex possesses better biological activity for the HL-60 cells of the leukemia than arsenic triiodide.

  5. Solid-State Synthesis of a Thermochromic Compound

    Changyun, Chen; Zhihua, Zhou; Yiming, Zhou; Jiangyan, Du

    2000-09-01

    Bis(diethylammonium) tetrachloronickelate(II) was prepared by solid-state reaction at mild temperature. Classroom demonstration of the synthesis and discussions of thermochromic mechanism of the compound prepared were described.

  6. Novel MoO2/carbon hierarchical nano/microcomposites: synthesis, characterization, solid state transformations and thiophene HDS activity.

    Avendaño, Carlos; Briceño, Alexander; Méndez, Franklin J; Brito, Joaquín L; González, Gema; Cañizales, Edgar; Atencio, Reinaldo; Dieudonné, Philippe

    2013-02-28

    Novel MoO(2)/C nano/microcomposites were prepared via a bottom-up approach by hydrothermal carbonization of a solution of glucose as a carbon precursor in the presence of polyoxometalates (POMs: phosphomolybdic acid [H(3)PMo(12)O(40)] and ammonium heptamolybdate tetrahydrate [(NH(4))(6)Mo(7)O(24)]·4H(2)O). The structural characterization by FT-IR, XRPD, SEM and TEM analyses revealed the controlled formation of hierarchical MoO(2)/C composites with different morphologies: strawberry-like, based on carbon microspheres decorated with MoO(2) nanoparticles; MoO(2)/C core-shell composites; and irregular aggregates in combination with ring-like microstructures bearing amorphous Mo species. These composites can be fine-tuned by varying reaction time, glucose/POM ratio and type of POM precursor. Subsequent transformations in the solid state through calcinations of MoO(2)/C core-shell composites in air lead to hollow nanostructured molybdenum trioxide microspheres together with nanorods and plate microcrystals or cauliflower-like composites (MoO(2)/C). In addition, the MoO(2)/C composite undergoes a morphology evolution to urchin-like composites when it is calcined under nitrogen atmosphere (MoO(2)/C-N(2)). The MoO(2)/C strawberry-like and MoO(2)/C-N(2) composites were transformed into Mo carbide and nitride supported on carbon microspheres (Mo(2)C/C, MoN/C, and MoN/C-N(2)). These phases were tested as precursors in thiophene hydrodesulphurization (HDS) at 400 °C, observing the following trend in relation to the thiophene steady-state conversion: MoN/C-N(2) > MoN/C > Mo(2)C/C > MoO(2)/C-N(2) > MoO(2)/C. According to these conversion values, a direct correlation was observed between higher HDS activity and decreasing crystal size as estimated from the Scherrer equation. These results suggest that such composites represent interesting and promising precursors for HDS catalysts, where the activity and stability can be modified either by chemical or structural changes of the

  7. The effects of mechanical activation energy on the solid-state synthesis process of BiFeO3

    Highlights: • BiFeO3 was successfully synthesized via a mechano-thermal route. • The effects of milling energy on the process were studied. • Applying an optimum milling energy lowered the formation temperature of BiFeO3. • Sample with optimum energy showed antiferromagnetic state and less leakage current. - Abstract: The effects of milling energy induced during intermediate mechanical activation of precursors on the synthesis of nano-structured BiFeO3 powders have been systematically investigated. X-ray diffractometer, laser particles size analyzer, field emission scanning electron microscope, vibrating sample magnetometer and electrical evaluation techniques were used to study phase composition, particles size distribution, morphology, magnetic properties and ferroelectric properties of the products, respectively. Applying a total energy of 171.18 kJ/g during milling led to formation of an amorphous structure which resulted in decreasing the formation temperature of bismuth ferrite phase by about 100 °C, although small amounts of secondary phases were detected. This sample shows the mean particles size of 170 nm and the mean crystallite size of 40 nm, when calcined at 750 °C. Saturation magnetization (MS) increased from 0.054 to 0.071 A m2/kg and coercive field (HC) decreased from 32.63 to 6.37 kA/m by increasing the milling energy from 13.48 to 171.18 kJ/g. In addition, electrical hysteresis loops demonstrated a decrease in the current leakage by increasing the milling energy and lowering the calcination temperature

  8. The effects of mechanical activation energy on the solid-state synthesis process of BiFeO{sub 3}

    Ahmadzadeh, M.; Ataie, A., E-mail: aataie@ut.ac.ir; Mostafavi, E.

    2015-02-15

    Highlights: • BiFeO{sub 3} was successfully synthesized via a mechano-thermal route. • The effects of milling energy on the process were studied. • Applying an optimum milling energy lowered the formation temperature of BiFeO{sub 3}. • Sample with optimum energy showed antiferromagnetic state and less leakage current. - Abstract: The effects of milling energy induced during intermediate mechanical activation of precursors on the synthesis of nano-structured BiFeO{sub 3} powders have been systematically investigated. X-ray diffractometer, laser particles size analyzer, field emission scanning electron microscope, vibrating sample magnetometer and electrical evaluation techniques were used to study phase composition, particles size distribution, morphology, magnetic properties and ferroelectric properties of the products, respectively. Applying a total energy of 171.18 kJ/g during milling led to formation of an amorphous structure which resulted in decreasing the formation temperature of bismuth ferrite phase by about 100 °C, although small amounts of secondary phases were detected. This sample shows the mean particles size of 170 nm and the mean crystallite size of 40 nm, when calcined at 750 °C. Saturation magnetization (M{sub S}) increased from 0.054 to 0.071 A m{sup 2}/kg and coercive field (H{sub C}) decreased from 32.63 to 6.37 kA/m by increasing the milling energy from 13.48 to 171.18 kJ/g. In addition, electrical hysteresis loops demonstrated a decrease in the current leakage by increasing the milling energy and lowering the calcination temperature.

  9. Energy-savvy solid-state and sonochemical synthesis of lithium sodium titanate as an anode active material for Li-ion batteries

    Ghosh, Swatilekha; Kee, Yongho; Okada, Shigeto; Barpanda, Prabeer

    2015-11-01

    Lithium sodium titanate insertion-type anode has been synthesized by classical solid-state (dry) and an alternate solution-assisted (wet) sonochemical synthesis routes. Successful synthesis of the target compound has been realized using simple Na- and Li-hydroxide salts along with titania. In contrast to the previous reports, these energy-savvy synthesis routes can yield the final product by calcination at 650-750 °C for limited duration of 1-10 h. Owing to the restricted calcination duration (dry route for 1-2 h and wet route for 1-5 h), they yield homogeneous nanoscale lithium sodium titanate particles. Sonochemical synthesis reduces the lithium sodium titanate particle size down to 80-100 nm vis-à-vis solid-state method delivering larger (200-500 nm) particles. Independent of the synthetic methods, the end products deliver reversible electrochemical performance with reversible capacity exceeding 80 mAh·g-1 acting as a 1.3 V anode for Li-ion batteries.

  10. The solid-state synthesis of tritium labelled heterocyclic bases

    Sidorov, G.V.; Myasoedov, N.F. (AN SSSR, Moscow (Russian Federation). Inst. Molekulyarnoj Genetiki)

    1994-04-01

    The results of a study of the solid-state catalytic hydrogenation and the synthesis of tritium labelled native heterocyclic bases are presented. The effect of different palladium catalysts and reaction conditions on yield and molar radioactivity of final compounds was investigated. For some compounds, data on the intramolecular distribution of tritium were obtained by using the isotope exchange reaction and tritium NMR. Tritium labelled purine and pyrimidine bases (25-180 Ci/mmol.) were synthesized. (Author).

  11. Solid-State Thermal Reaction of a Molecular Material and Solventless Synthesis of Iron Oxide

    Roy, Debasis; Roy, Madhusudan; Zubko, Maciej; Kusz, Joachim; Bhattacharjee, Ashis

    2016-09-01

    Solid-state thermal decomposition reaction of a molecular material {As}({C}6{H}5)4[{Fe}^{II}{Fe}^{III} ({C}2{O}4)3]}n has been studied using non-isothermal thermogravimetry (TG) in an inert atmosphere. By analyzing the TG data collected at multiple heating rates in 300 K-1300 K range, the kinetic parameters (activation energy, most probable reaction mechanism function and frequency factor) are determined using different multi-heating rate analysis programs. Activation energy and the frequency factor are found to be strongly dependent on the extent of decomposition. The decomposed material has been characterized to be hematite using physical techniques (FT-IR and powder XRD). Particle morphology has been checked by TEM. A solid-state reaction pathway leading the molecular precursor to hematite has been proposed illustrating an example of solventless synthesis of iron oxides utilizing thermal decomposition as a technique using innocuous materials.

  12. Solid-state Synthesis of Carbon-nanostructures

    R.Wilhelm; A.Winkel; D.Jain

    2007-01-01

    1 Results In addition to single wall and multiwall carbon nanotubes[1], several structures,which are more or less related to fullerenes,including carbon nanohorns[2a], carbon nanospheres[2b] and onion like carbon structures[2c] have been reported.A new simple straight forward method to access some of these structures is the solid-state pyrolysis of different organometallic complexes in a sealed vessel,which led so far to carbon nanotubes[3a,b], carbon nanocables[3c] and onions[3d].

  13. Synthesis of Ba0.75Sr0.25Al2Si2O8 - ZrO2 Ceramic Composites by Solid State Reaction of Mechanically Activated Precursor Mixtures

    Precursor mixtures composed of fly ash, BaCO3, SrCO3, Al2O3 and ZrO2, were subjected to attrition milling for 0-8 h and then uniaxially pressed and sintered at 900-1500 degree centigrade/5 h, for the in situ solid state synthesis of composites with nominal Ba0.75Sr0.25Al2Si2O8 (SBAS)/ZrO2 mass ratios of: 1) 90/10, 2) 70/30, and 3) 50/50. Mechanical activation, combined with the likely generation of a considerable amount of transient liquid during sintering of the composites, notably enhanced the reactivity of the precursor mixtures. ZrO2 decreased the conversion from the hexagonal (Hexacelsian) into the monoclinic (Celsian) phases of SBAS in the composites, which became more pronounced when the content of ZrO2 was increased in the materials. Nearly full conversions could be achieved at temperatures as low as 1100 degree centigrade, by mechanically activating the precursor mixtures for times that increased with increasing content of ZrO2 in the materials. An increment in the time of mechanical activation of the precursor mixtures, as well as in their ZrO2 content and in the sintering temperature, increased the mechanical properties of the synthesized materials. Thus, the best mechanical properties were obtained for composition 3 milled for 8 h and sintered at 1500 degree centigrade. (Author)

  14. Method for increasing -SiC yield on solid state reaction of coal fly ash and activated carbon powder

    Sulardjaka; Jamasri; M W Wildan; Kusnanto

    2011-07-01

    A novel process for increasing -SiC yield on solid state reaction of coal fly ash and micro powder activated carbon powder has been proposed. -SiC powder was synthesized at temperature 1300°C for 2 h under vacuum condition with 1 l/min argon flow. Cycling synthesis process has been developed for increasing -SiC yield on solid state reaction of coal fly ash and activated carbon powder. Synthesized products were analyzed by XRD with Cu-K radiation, FTIR spectrometer and SEM fitted with EDAX. The results show that the amount of relative -SiC is increased with the number of cycling synthesis.

  15. Solid State Synthesis and Properties of Monoclinic Celsian

    Bansal, Narottam P.

    1996-01-01

    Monoclinic celsian of Ba(0.75)Sr(0.25)Al2Si2O8 (BSAS-1) and B(0.85)Sr(O.15)Al2Si2O8 (BSAS-2) compositions have been synthesized from metal carbonates and oxides by solid state reaction. A mixture of BaCO3, SrCO3, Al2O3, and SiO2 powders was precalcined at approx. 900-940 C to decompose the carbonates followed by hot pressing at approx. 1300 C. The hot pressed BSAS-1 material was almost fully dense and contained the monoclinic celsian phase, with complete absence of the undesirable hexacelsian as indicated by x-ray diffraction. In contrast, a small fraction of hexacelsian was still present in hot pressed BSAS-2. However, on further heat treatment at 1200 C for 24 h, the hexacelsian phase was completely eliminated. The average linear thermal expansion coefficients of BSAS-1 and BSAS-2 compositions, having the monoclinic celsian phase, were measured to be 5.28 x 10(exp -6)/deg C and 5.15 x 10(exp -6)/deg C, respectively from room temperature to 1200 C. The hot pressed BSAS-1 celsian showed room temperature flexural strength of 131 MPa, elastic modulus of 96 GPa and was stable in air up to temperatures as high as approx. 1500 C.

  16. Mechano-thermally activated solid-state synthesis of Li{sub 4}Ti{sub 5}O{sub 12} spinel from Li{sub 2}CO{sub 3}-TiO{sub 2} mixtures

    Berbenni, Vittorio; Milanese, Chiara; Bruni, Giovanna; Marini, Amedeo [CSGI - Unita Operativa di Pavia, Dipt. di Chimica Fisica della Univ. di Pavia (Italy)

    2010-01-15

    Simultaneous TG/DSC measurements performed on mixtures 2Li{sub 2}CO{sub 3}-5TiO{sub 2} (anatase) subjected to high-energy milling showed that both the temperature and the enthalpy of Li{sub 2}CO{sub 3} decomposition are much lower than in the case of TG/DSC runs performed on a sample of a physical mixture. On the basis of the thermoanalytical evidence a solid-state synthesis of the spinel compound Li{sub 4}Ti{sub 5}O{sub 12} has been proposed that combines mechanical (by high-energy milling) and thermal activation (8 h annealing at 973 K): the obtained compound shows a lattice constant in very good agreement with that expected for the pure phase Li{sub 1+x}Ti{sub 2-x}O{sub 4} (x = 0.333). The molar heat capacity of Li{sub 4}Ti{sub 5}O{sub 12} has been determined in the temperature range 323 - 633 K by quasi-isothermal Modulated Differential Scanning Calorimetry (MDSC). The specific surface area of Li{sub 4}Ti{sub 5}O{sub 12} has been determined by gas adsorption. (orig.)

  17. Solid-State Microwave Synthesis of Melamine-Formaldehyde Resin

    Subhash Bajia; Rashmi Sharma; Birbal Bajia

    2009-01-01

    An efficient synthesis of melamine-formaldehyde resin has been achieved using conventional as well as microwave irradiations (without and with solid support) in different molar ratio. Resin samples were tested for their chemical as well as physical properties. The structure of all the resin has been supported by their spectral data

  18. Synthesis and solid state NMR characterization of novel peptide/silica hybrid materials.

    Werner, Mayke; Heil, Andreas; Rothermel, Niels; Breitzke, Hergen; Groszewicz, Pedro Braga; Thankamony, Aany Sofia; Gutmann, Torsten; Buntkowsky, Gerd

    2015-11-01

    The successful synthesis and solid state NMR characterization of silica-based organic-inorganic hybrid materials is presented. For this, collagen-like peptides are immobilized on carboxylate functionalized mesoporous silica (COOH/SiOx) materials. A pre-activation of the silica material with TSTU (O-(N-Succinimidyl)-N,N,N',N'-tetramethyluronium tetrafluoroborate) is performed to enable a covalent binding of the peptides to the linker. The success of the covalent immobilization is indicated by the decrease of the (13)C CP-MAS NMR signal of the TSTU moiety. A qualitative distinction between covalently bound and adsorbed peptide is feasible by (15)N CP-MAS Dynamic Nuclear Polarization (DNP). The low-field shift of the (15)N signal of the peptide's N-terminus clearly identifies it as the binding site. The DNP enhancement allows the probing of natural abundance (15)N nuclei, rendering expensive labeling of peptides unnecessary. PMID:26411982

  19. Solid state synthesis of starch-capped silver nanoparticles.

    Hebeish, A; Shaheen, Th I; El-Naggar, Mehrez E

    2016-06-01

    The present research addresses the establishment of a technique which is solely devoted to environmentally friendly one-pot green synthesis of dry highly stable powdered silver nanoparticles (AgNPs) using starch as both reductant and stabilizing agent in the presence of sodium hydroxide. It is believed that the sodium hydroxide can improve the reduction potential of starch. Thus when the alkali treated starch is submitted to addition of silver nitrate (AgNO3), the alkali treated starch induces the well-established dual role of starch; reduction of silver ions (Ag(+)) to AgNPs and capping the as-formed AgNPs to prevent them from further growth and agglomeration. Beside assessment of AgNPs formation, structural and morphological characteristics of AgNPs are investigated by making use of UV-vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, FT-IR and X-ray diffraction (XRD) analysis. Research outputs signify (a) the absorbance around 410-420nm in the UV-vis spectra of AgNPs appears most, probably owing to the presence of nanosized silver particles and the intensity of this peak increases by increasing AgNO3 concentration; (b) that highly stable AgNPs with well-dispersed particle are successfully prepared using the present research-based innovation; (c) that the size of AgNPs does not exceed 30nm with sphere-like morphology even at the highest Ag(+) concentration employed during synthesis operation; (d) that the XRD and FT-IR confirm the successful preparation of pure AgNPs without noticeable impurities; (d) and that the one-pot synthesis of powdered AgNPs in large scale is clean and easily operated and easily transportation which may be applied as per demands of industries such as textile and painting industry. PMID:26902893

  20. Polyol accumulation by Aspergillus oryzae at low water activity in solid-state fermentation

    Ruijter, G.J.G.; Visser, J.; Rinzema, A.

    2004-01-01

    Polyol accumulation and metabolism were examined in Aspergillus oryzae cultured on whole wheat grains or on wheat dough as a model for solid-state culture. In solid-state fermentation (SSF), water activity (a(w)) is typically low resulting in osmotic stress. In addition to a high level of mannitol,

  1. Solid state support for the synthesis of [1-11C]-putrescine

    A novel solid state support was demonstrated using [11C]-HCN for the radiosynthesis of [1-11C]-putrescine by the Michael addition reaction to acrylonitrile. The silica gel support allowed near quantitative trapping of the [11C]-HCN and its efficient use under anhydrous conditions. The absence of water during the addition reaction eliminated by-product formation and reduced the overall synthesis and purification time required for the preparation of the radiopharmaceutical. A radiochemical yield of 53 ± 4 was achieved for purified product within 40 min of EOB. The process can be automated for the routine synthesis of [1-11C]-putrescine radiopharmaceutical. (author)

  2. High-pressure synthesis of rhombohedral α-AgGaO{sub 2} via direct solid state reaction

    Akhtar, Meysam [Department of Physics and Astronomy, University of Louisville, 102 Natural Science Building, Louisville, KY 40292 (United States); Menon, Madhu [Center for Computational Sciences, University of Kentucky, 325 McVey Hall, Lexington, KY 40506 (United States); Sunkara, Mahendra [Conn Center for Renewable Energy Research, University of Louisville, Ernst Hall Room 102A, Louisville, KY 40292 (United States); Sumanasekera, Gamini [Department of Physics and Astronomy, University of Louisville, 102 Natural Science Building, Louisville, KY 40292 (United States); Conn Center for Renewable Energy Research, University of Louisville, Ernst Hall Room 102A, Louisville, KY 40292 (United States); Durygin, Andriy [Center for the Study of Matter at Extreme Conditions, Florida International University, VH 140, University Park, Miami, FL 33199 (United States); Jasinski, Jacek B., E-mail: jacek.jasinski@louisville.edu [Conn Center for Renewable Energy Research, University of Louisville, Ernst Hall Room 102A, Louisville, KY 40292 (United States)

    2015-08-25

    Highlights: • Direct synthesis of α-AgGaO{sub 2} via a solid state reaction of Ag{sub 2}O and Ga{sub 2}O{sub 3} powders. • Utilizing high pressure diamond anvil cell to facilitate solid state reaction. • Experimental and theoretical study of vibrational modes for α-AgGaO{sub 2}. • Extensive characterization of synthesized α-AgGaO{sub 2} samples. • GGA + U formalism-based DFT calculations of electronic structure and band gap in α-AgGaO{sub 2}. - Abstract: In this work, we demonstrate the application of high pressure conditions to enable the direct synthesis of α-AgGaO{sub 2} via a solid state reaction of Ag{sub 2}O and Ga{sub 2}O{sub 3}. Synthesis experiments were carried out at pressures and temperatures up to ∼10 GPa and ∼600 °C, respectively, using a resistively-heated diamond anvil cell. Thus synthesized α-AgGaO{sub 2} samples were characterized and their chemical composition and crystal structure were confirmed. In particular, electron diffraction confirmed the rhombohedral delafossite crystal structure of the synthesized AgGaO{sub 2} and its corresponding lattice parameters of a = 2.99 Å and c = 18.43 Å. The vibrational modes analysis was also conducted using a combination of ab initio density functional theory (DFT) and Raman spectroscopy. This analysis yielded good agreement between the calculated Raman-active modes and experimental Raman data. Finally, the application of the GGA + U formalism-based on DFT to calculate the electronic band structure of α-AgGaO{sub 2} provided a more realistic theoretical band gap value than those reported previously.

  3. Low-Temperature Synthesis of Actinide Tetraborides by Solid-State Metathesis Reactions

    Lupinetti, Anthony J.; Garcia, Eduardo; Abney, Kent D.

    2004-12-14

    The synthesis of actinide tetraborides including uranium tetraboride (UB,), plutonium tetraboride (PUB,) and thorium tetraboride (ThB{sub 4}) by a solid-state metathesis reaction are demonstrated. The present method significantly lowers the temperature required to {approx_equal}850 C. As an example, when UCl{sub 4}, is reacted with an excess of MgB{sub 2}, at 850 C, crystalline UB, is formed. Powder X-ray diffraction and ICP-AES data support the reduction of UCl{sub 3}, as the initial step in the reaction. The UB, product is purified by washing water and drying.

  4. Synthesis and characterization of nanowires Hausmannite (Mn3O4) by solid-state thermal decomposition

    A. A. Dehno Khalaji; F. Malekan

    2014-01-01

    In this study, we synthesis one-dimensional (1D) manganese(III) Schiff base coordination polymer [Mn(Brsalophen)(μ1,3-N3)]n by reaction of MnCl2·6H2O and tetradentate Schiff base ligand Brsalophen at the presence of NaN3 in methanol and characterized by elemental analyses (CHN) and FT-IR spectroscopy. It was used as a new precursor to prepare spinel type manganese oxide nanowires by a facile solid-state thermal decomposition in air at 400ºC for 3.5 h. The crystallinity, purity and morphology ...

  5. Synthesis of alpha-amylase by Aspergillus oryzae in solid-state fermentation.

    Francis, Febe; Sabu, A; Nampoothiri, K Madhavan; Szakacs, George; Pandey, Ashok

    2002-01-01

    Spent Brewing Grains (SBG) was evaluated for its efficacy to be used as sole carbon source for the synthesis of alpha-amylase in solid-state fermentation using a fungal strain of Aspergillus oryzae NRRL 6270. Enzyme production was superior when the culture grew on mesophilic temperatures and best yields were at 25 degrees C. At 30 degrees C, yields were almost comparable. Maximum production of alpha-amylase [6870 U/g dry substrate (gds)] was obtained when SSF was carried out at 30 degrees C for 96 h using SBG medium, which had initial moisture of 70% and was inoculated using a spore suspension containing 1 x 10(7) spores/ml. Supplementation of SBG with external carbon sources such as mono-, di and polysaccharides caused repression in enzyme synthesis by the fungal culture. PMID:12362403

  6. Solid state synthesis of extra phase-pure Li4Ti5O12 spinel

    Veljković I.

    2011-01-01

    Full Text Available Extra phase-pure Li4Ti5O12 spinel with particle sizes less than 500 nm was synthesized by solid state reaction of mechanochemicaly activated mixture of nano anatase and Li2CO3 for a very short annealing time, 4 h at 800°C. Structural and microstructural properties, the mechanism of solid state reaction between anatase and Li2CO3 as well as thermal stability of prepared spinel were investigated using XRPD, SEM and TG/DSC analysis. The mechanism of reaction implies decomposition of Li2CO3 below 250ºC, formation of monoclinic Li2TiO3 as intermediate product between 400 and 600°C and its transformation to Li4Ti5O12 between 600-800ºC. The spinel structure is stable up to 1000ºC when it is decomposed due to Li2O evaporation.

  7. Synthesis, Structure and Solid State Properties of Cyclohexanemethylamine Substituted Phenalenyl Based Molecular Conductor

    Robert C. Haddon

    2012-05-01

    Full Text Available We report the preparation, crystallization and solid state characterization of a cyclohexanemethylamine substituted spirobiphenalenyl radical; in the solid state the compound is iso-structural with its dehydro-analog (benzylamine-substitued compound, and the molecules packed in a one-dimensional fashion that we refer to as a π-step stack. Neighboring molecules in the stack interact via the overlap of one pair of active (spin bearing carbon atoms per phenalenyl unit. The magnetic susceptibility measurement indicates that in the solid state the radical remains paramagnetic and the fraction of Curie spins is 0.75 per molecule. We use the analytical form of the Bonner-Fisher model for the S = 1/2 antiferromagnetic Heisenberg chain of isotropically interacting spins with intrachain spin coupling constant J = 6.3 cm−1, to fit the experimentally observed paramagnetism [χp (T] in the temperature range 4–330 K. The measured room temperature conductivity (σRT = 2.4 × 10–3 S/cm is comparable with that of the iso-structural benzyl radical, even though the calculated band dispersions are smaller than that of the unsaturated analog.

  8. Synthesis of pyridine- and pyrazine-BF3 complexes and their characterization in solution and solid state.

    Chenard, Etienne; Sutrisno, Andre; Zhu, Lingyang; Assary, Rajeev S.; Kowalski, Jeffrey A; Barton, John L.; Bertke, Jeffery A.; Gray, Danielle; Brushett, Fikile R; Curtiss, Larry A.; Moore, Jeffrey S.

    2016-04-28

    Following the discovery of the redox-active 1,4- bis-BF3-quinoxaline complex, we undertook a structure- activity study with the objective to understand the active nature of the quinoxaline complex. Through systematic synthesis and characterization, we have compared complexes prepared from pyridine and pyrazine derivatives, as heterocyclic core analogues. This paper reports the structural requirements that give rise to the electrochemical features of the 1,4-bis-BF3-quinoxaline adduct. Using solution and solidstate NMR spectroscopy, the role of aromatic ring fusion and nitrogen incorporation in bonding and electronics was elucidated. We establish the boron atom location and its interaction with its environment from 1D and 2D solution NMR, X-ray diffraction analysis, and 11B solid-state NMR experiments. Crystallographic analysis of single crystals helped to correlate the boron geometry with 11B quadrupolar coupling constant (CQ) and asymmetry parameter (ηQ), extracted from 11B solid-state NMR spectra. Additionally, computations based on density functional theory were performed to predict electrochemical behavior of the BF3-heteroaromatic complexes. We then experimentally measured electrochemical potential using cyclic voltammetry and found that the redox potentials and CQ values are similarly affected by electronic changes in the complexes.

  9. Solid state reaction synthesis of Ba0.75Sr0.25AlSi2O8 - Al2O3 ceramic composites from mechanically activated precursor mixtures

    Ceramic composites with Ba0.75Sr0.25AlSi2O8 (SBAS)/Al2O3 mass ratios of: 1) 90/10, 2) 70/30, and 3) 50/50, were in situ synthesized at 900-1500 degree centigrade/5 h from mixtures of fly ash, BaCO3, SrCO3 and Al2O3. The green mixtures were mechanically activated for 0, 4 and 8 h in an attrition mill. As a result, the solid state reactions were faster and occurred at lower temperatures. Only the SBAS and Al2O3 phases were obtained at 1300-1500 degree centigrade, with the SBAS present in composition 1 achieving full conversion from its hexagonal (Hexacelsian) into its monoclinic (Celsian) form, with or without milling. The higher nominal SBAS content of composition 1 facilitated in it the mentioned conversion, in comparison with the other two studied compositions, which required to be mechanically activated for times that increased with increasing Al2O3 content, in order to attain in them similarly high Hexacelsian to Celsian conversions. The mechanical properties of the synthesized materials increased with increasing milling time, sintering temperature and Al2O3 content. Thus, the best mechanical properties were obtained for composition 3 milled for 8 h and sintered at 1500 degree centigrade. (Author)

  10. Solid State Inflation Balloon Active Deorbiter: Scalable Low-Cost Deorbit System for Small Satellites

    Huang, Adam

    2016-01-01

    The goal of the Solid State Inflation Balloon Active Deorbiter project is to develop and demonstrate a scalable, simple, reliable, and low-cost active deorbiting system capable of controlling the downrange point of impact for the full-range of small satellites from 1 kg to 180 kg. The key enabling technology being developed is the Solid State Gas Generator (SSGG) chip, generating pure nitrogen gas from sodium azide (NaN3) micro-crystals. Coupled with a metalized nonelastic drag balloon, the complete Solid State Inflation Balloon (SSIB) system is capable of repeated inflation/deflation cycles. The SSGG minimizes size, weight, electrical power, and cost when compared to the current state of the art.

  11. Polyol accumulation by Aspergillus oryzae at low water activity in solid-state fermentation

    Ruijter, G J G; J. Visser; Rinzema, A.

    2004-01-01

    Polyol accumulation and metabolism were examined in Aspergillus oryzae cultured on whole wheat grains or on wheat dough as a model for solid-state culture. In solid-state fermentation (SSF), water activity (a(w)) is typically low resulting in osmotic stress. In addition to a high level of mannitol, which is always present in the cells, A. oryzae accumulated high concentrations of glycerol, erythritol and arabitol at relatively low a(w) (0(.)96-0(.)97) in SSF. Accumulation of such a mixture of...

  12. Solid State Division

    This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces

  13. Solid State Division

    Green, P.H.; Watson, D.M. (eds.)

    1989-08-01

    This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces. (LSP)

  14. Solid state synthesis and sintering of monazite-type ceramics: application to minor actinides conditioning

    In the framework of the French law of 1991 concerning the nuclear waste management, several studies are undertaken to develop specific crystalline conditioning matrices. Monazite, a rare earth (TR3+) orthophosphate with a general formula TR3+PO4, is a natural mineral containing significant amount of thorium and uranium. Monazite has been proposed as a host matrix for the minor actinides (Np, Am and Cm) specific conditioning, thanks to its high resistance to self irradiation and its low solubility. Its is now of prime importance to check the conservation of these properties on synthesized materials, which implies to master all the stages of the elaboration process, from the powder synthesis to the sintering of controlled microstructure pellets. This work can be divided into two main parts: The first part deals with the synthesis by high temperature solid state route of TR3+PO4 powders (with TR3+ = La3+ to Gd3+, Pu3+ and Am3+). The chemical reactions occurring during the firing of starting reagents are described in the case of monazite with only one or several cations. From these results, a protocol of synthesis is described. The incorporation of tetravalent cations (Ce4+, U4+, Pu4+) in the monazite structure was also studied. The second part of the present work deals with the elaboration of controlled density and microstructure monazite pellets and their related mechanical and thermal properties. The study of crushing and sintering is presented. For the first time, experimental results are confronted with theoretical models in order to deduce the densification and grain growth mechanisms. By the comprehension of the various physicochemical phenomena occurring during the various stages of the monazite pellets elaboration process (powder synthesis, crushing, sintering...), this work allowed the development of a protocol of elaboration of controlled microstructure monazite TR3+PO4 pellets. The determination of some mechanical and thermal properties could thus be

  15. Synthesis of single phase cubic Al-substituted Li7La3Zr2O12 by solid state lithiation of mixed hydroxides

    Highlights: • Soft chemistry synthesis of pure phase cubic-LLZ solid electrolyte. • Solid state lithiation of hydroxide precipitates. • Homogeneous distribution of constituting elements in the product. • Temperature dependent Li-ion conductivity of the LLZ was characterized. - Abstract: Substituted Li7La3Zr2O12 (LLZ) with cubic garnet type structure is a promising candidate for solid state electrolyte in all-solid-state batteries. Here we present a novel synthesis route to obtain single phase cubic Al-substituted LLZ. The two step method consists of a co-precipitation of metal hydroxides from aqueous solution as well as solid-state lithiation and crystallization of the dried precipitate. Morphology and chemical composition of precipitated particles were investigated with SEM and EDS. Phase composition of calcined powder was confirmed to be pure phase cubic LLZ via XRD. The temperature dependent lithium ion conduction of a sintered pellet was determined to be 6.3 · 10−5 S/cm at 353 K with an activation energy of 0.58 eV

  16. A General Solid-State Synthesis of Chemically-Doped Fluorescent Graphene Quantum Dots for Bioimaging and Optoelectronic Applications

    Ma, Chong-Bo

    2015-05-05

    Graphene quantum dots (GQDs) have attracted increasing interest because of their excellent properties such as strong photoluminescence, excellent biocompatibility and low cost. Herein, we develop a general method for the synthesis of doped and undoped GQDs, which relies on direct carbonization of organic precursors at solid state.

  17. Organometallic synthesis, reactivity and catalysis in the solid state using well-defined single-site species

    Pike, Sebastian D.; Weller, Andrew S.

    2015-01-01

    Acting as a bridge between the heterogeneous and homogeneous realms, the use of discrete, well-defined, solid-state organometallic complexes for synthesis and catalysis is a remarkably undeveloped field. Here, we present a review of this topic, focusing on describing the key transformations that can be observed at a transition-metal centre, as well as the use of well-defined organometallic complexes in the solid state as catalysts. There is a particular focus upon gas–solid reactivity/catalysis and single-crystal-to-single-crystal transformations. PMID:25666064

  18. MOCVD synthesis of group III-nitride heterostructure nanowires for solid-state lighting.

    Wang, George T.; Creighton, James Randall; Talin, Albert Alec

    2006-11-01

    Solid-state lighting (SSL) technologies, based on semiconductor light emitting devices, have the potential to reduce worldwide electricity consumption by more than 10%, which could significantly reduce U.S. dependence on imported energy and improve energy security. The III-nitride (AlGaInN) materials system forms the foundation for white SSL and could cover a wide spectral range from the deep UV to the infrared. For this LDRD program, we have investigated the synthesis of single-crystalline III-nitride nanowires and heterostructure nanowires, which may possess unique optoelectronic properties. These novel structures could ultimately lead to the development of novel and highly efficient SSL nanodevice applications. GaN and III-nitride core-shell heterostructure nanowires were successfully synthesized by metal organic chemical vapor deposition (MOCVD) on two-inch wafer substrates. The effect of process conditions on nanowire growth was investigated, and characterization of the structural, optical, and electrical properties of the nanowires was also performed.

  19. Synthesis and characterization of nanowires Hausmannite (Mn3O4 by solid-state thermal decomposition

    A. A. Dehno Khalaji

    2014-12-01

    Full Text Available In this study, we synthesis one-dimensional (1D manganese(III Schiff base coordination polymer [Mn(Brsalophen(μ1,3-N3]n by reaction of MnCl2·6H2O and tetradentate Schiff base ligand Brsalophen at the presence of NaN3 in methanol and characterized by elemental analyses (CHN and FT-IR spectroscopy. It was used as a new precursor to prepare spinel type manganese oxide nanowires by a facile solid-state thermal decomposition in air at 400ºC for 3.5 h. The crystallinity, purity and morphology of the Mn3O4 products were characterized by powder X-ray diffraction (XRD and scanning electron microscopy (SEM. The powder X-ray diffraction and scanning electron microscopy confirmed that the prepared Mn3O4 nanowires are pure single phases. The present method allows preparation of the Mn3O4 nanowires without expensive or toxic organic solvent and complicated equipment. The nanowires have a diameter about ≈25 nm and length exceeding 1.5 μm. It has potential to be applied as a general method for preparation of other transition metal oxide nanoparticles.

  20. Theoretical solid state physics

    Research activities at ORNL in theoretical solid state physics are described. Topics covered include: surface studies; particle-solid interactions; electronic and magnetic properties; and lattice dynamics

  1. Solid state structural and theoretical investigations of a biologically active chalcone

    Abbas, Asghar; Gökce, Halil; Bahceli, Semiha; Bolte, Michael; Naseer, Muhammad Moazzam

    2016-05-01

    The computational methods are presently emerging as an efficient and reliable tool for predicting structural properties of biologically important compounds. In the present manuscript, the solid state structural and theoretical investigations of a biologically active chalcone i-e (E)-3-(4-(hexyloxy)phenyl)-1-phenylprop-2-en-1-one (6c) have been reported. The solid state structure of 6c was measured by X-ray crystallographic technique whereas the optimized molecular geometry, vibrational frequencies, the simulated UV-vis spectra (in gas and in methanol solvent), 1H and 13C NMR chemical shift (in gas and in chloroform solvent) values, HOMO-LUMO analysis, the molecular electrostatic potential (MEP) surface and thermodynamic parameters were calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set in ground state. The results of the theoretical investigations were found to be in good agreement with experimental data.

  2. Solid state photon upconversion utilizing thermally activated delayed fluorescence molecules as triplet sensitizer

    Wu, Tony C.; Congreve, Daniel N.; Baldo, Marc A., E-mail: baldo@mit.edu [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-07-20

    The ability to upconvert light is useful for a range of applications, from biological imaging to solar cells. But modern technologies have struggled to upconvert incoherent incident light at low intensities. Here, we report solid state photon upconversion employing triplet-triplet exciton annihilation in an organic semiconductor, sensitized by a thermally activated-delayed fluorescence (TADF) dye. Compared to conventional phosphorescent sensitizers, the TADF dye maximizes the wavelength shift in upconversion due to its small singlet-triplet splitting. The efficiency of energy transfer from the TADF dye is 9.1%, and the conversion yield of sensitizer exciton pairs to singlet excitons in the annihilator is 1.1%. Our results demonstrate upconversion in solid state geometries and with non-heavy metal-based sensitizer materials.

  3. Maximizing the temperature span of a solid state active magnetic regenerative refrigerator

    Highlights: • A fully solid state active magnetic regenerative refrigerator is proposed. • The temperature span is enhanced by increasing the number of magnetocaloric elements. • Numerical simulations show that the temperature span can reach 11.4 K at 303 K. • Optimization in terms of frequency, operating temperature and contact time. - Abstract: We here describe and numerically simulate a new solid state active magnetic regenerative refrigerator (AMRR) aiming bulk applications. This system uses magnetocaloric materials and materials whose thermal conductivity changes with the applied magnetic field (H). Similarly to common AMRRs, H is moved gradually from the hot to the cold reservoirs to produce a cascade of Brayton cycles. This cascade increases the temperature span and can thus be used in bulk applications where the conservation of a cold environment is demanded. Our results show that by using gadolinium as magnetocaloric material (MCM) and H = 1 T, one can increase the temperature span from 2.5 K up to 11.5 K, an enhancement of over 450%. The optimization of such solid state system is here presented also in terms of frequency, operating temperature and time of contact between the cold reservoir and the MCM

  4. Synthesis and characterization of nanostructured electrodes for solid state ionic devices

    Zhang, Yuelan

    exceeds the diffusion-limited rate of Li+ transport within the bulk phase of an electrode, concentration polarization occurs. Further, large volume changes associated with Li+ insertion or extraction could induce stresses in bulk electrodes, potentially leading to mechanical failure. Porous electrodes with high surface-to-volume ratio would increase the electrochemical reaction surface and suppress the mechanical stress. But porous electrodes also increase the tortuosity of mass transport within solid electrodes. Interconnected porous materials would decrease the percolation threshold for porous electrodes. In this work, electrodes with unique architecture for lithium ion batteries have been fabricated to improve the cycleability, rate capability and capacity retention. Spinel LiMn2O4 with interconnected macropores was created using a glycine-nitrate combustion process. Both microstructure and phase crystallinity were optimized by adjusting the fuel/oxidant ratio. This macroporous LiMn2O4 positive electrode exhibited better capacity retention and rate capability than those with larger particle size prepared by solid state reaction. Detailed electrode kinetic studies indicated that the macroporous microstructure promoted lithium diffusion and the overall reaction process was not controlled by lithium diffusion. Nanostructured tin oxide thin films with columnar grains less than 20 nm were deposited on Au/Si substrate using a combustion CVD method. The microstructure was highly porous and open, and thus was easily accessible to liquid electrolyte. In addition, the microstructure with vertical and radial connectivity of active materials led to decreased tortuosity for mass transport within solid electrodes. Nanoparticles accommodated the large volume change during cycling. These thin film electrodes exhibited highly reversible specific capacity and good capacity retention. It is about 93% after 80 cycles at a charge/discharge rate of 0.3 mA/cm2. When discharged at 0.9 mA/cm2

  5. Effects of Solid-State Reaction Synthesis Processing Parameters on Thermoelectric Properties of Mg2Si

    JIANG Hong-yi; LONG Hai-shan; ZHANG Lian-meng

    2004-01-01

    The Mg2Si-matrix thermoelectric material was synthesized by low temperature solid-state reaction.This paper studies the effects of holding time and reaction temperature on the particle size and the properties of the material,and also studies effects of doping elemental Sb,Te and their doping seqence on the properties of the material.The result shows that excessively high temperature and elongated holding time of solid-state reaction are harmful,there is a range of particle size to ensure optimum properties and the doping sequence of Sb or Te without influencing the properties.

  6. A green synthesis of a layered titanate, potassium lithium titanate; lower temperature solid-state reaction and improved materials performance

    A layered titanate, potassium lithium titanate, with the size range from 0.1 to 30 µm was prepared to show the effects of the particle size on the materials performance. The potassium lithium titanate was prepared by solid-state reaction as reported previously, where the reaction temperature was varied. The reported temperature for the titanate preparation was higher than 800 °C, though 600 °C is good enough to obtain single-phase potassium lithium titanate. The lower temperature synthesis is cost effective and the product exhibit better performance as photocatalysts due to surface reactivity. - Graphical abstract: Finite particle of a layered titanate, potassium lithium titanate, was prepared by solid-state reaction at lower temperature to show modified materials performance. Display Omitted - Highlights: • Potassium lithium titanate was prepared by solid-state reaction. • Lower temperature reaction resulted in smaller sized particles of titanate. • 600 °C was good enough to obtain single phased potassium lithium titanate. • The product exhibited better performance as photocatalyst

  7. Microwave assisted synthesis and solid-state characterization of lithocholyl amides of isomeric aminopyridines

    Ahonen, K. V.; Lahtinen, M. K.; Valkonen, A. M.; Dračínský, Martin; Kolehmainen, E. T.

    2011-01-01

    Roč. 76, č. 3 (2011), s. 261-268. ISSN 0039-128X R&D Projects: GA AV ČR KJB400550903 Grant ostatní: AV ČR(CZ) M200380901; Academy of Finland(FI) 7127006; Academy of Finland(FI) 212588 Institutional research plan: CEZ:AV0Z40550506 Keywords : solid-state NMR * x-ray diffraction * litocholic acid Subject RIV: CC - Organic Chemistry Impact factor: 2.829, year: 2011

  8. Template-Engaged Solid-State Synthesis of Barium Magnesium Silicate Yolk@Shell Particles and Their High Photoluminescence Efficiency.

    Chen, Xuncai; Kim, Woo-Sik

    2016-05-17

    This study presents a new synthetic method for fabricating yolk@shell-structured barium magnesium silicate (BMS) particles through a template-engaged solid-state reaction. First, as the core template, (BaMg)CO3 spherical particles were prepared based on the coprecipitation of Ba(2+) and Mg(2+) . These core particles were then uniformly shelled with silica (SiO2 ) by using CTAB as the structure-directing template to form (BaMg)CO3 @SiO2 particles with a core@shell structure. The (BaMg)CO3 @SiO2 particles were then converted to yolk@shell barium magnesium silicate (BMS) particles by an interfacial solid-state reaction between the (BaMg)CO3 (core) and the SiO2 (shell) at 750 °C. During this interfacial solid-state reaction, Kirkendall diffusion contributed to the formation of yolk@shell BMS particles. Thus, the synthetic temperature for the (BaMg)SiO4 :Eu(3+) phosphor is significantly reduced from 1200 °C with the conventional method to 750 °C with the proposed method. In addition, the photoluminescence intensity of the yolk@shell (BaMg)SiO4 :Eu(3+) phosphor was found to be 9.8 times higher than that of the conventional (BaMg)SiO4 :Eu(3+) phosphor. The higher absorption of excitation light by the structure of the yolk@shell phosphor is induced by multiple light-reflection and -scattering events in the interstitial void between the yolk and the shell. When preparing the yolk@shell (BaMg)SiO4 :Eu(3+) phosphor, a hydrogen environment for the solid-state reaction results in higher photoluminescence efficiency than nitrogen and air environments. The proposed synthetic method can be easily extended to the synthesis of other yolk@shell multicomponent metal silicates. PMID:27059894

  9. Copper Oxide Nanoparticles Prepared by Solid State Thermal Decomposition: Synthesis and Characterization

    Ensieh Shahsavani

    2016-06-01

    Full Text Available In this paper, we have focused on the preparation and characterization of copper oxide nanoparticles by solid state thermal decomposition of copper(I iodide in the presence of thiosemicarbazone ligands without the need for a catalyst, employing toxic solvent, template or surfactant and complicated equipment, which makes it efficient, one-step, simple and environment-friendly. CuO nanoparticles were achieved at 600 ˚C for 3 h as black products and characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray powder diffraction (XRD and transmission electron microscopy (TEM. The FT-IR spectra of black powders prepared show absorption maxima at ≈ 525 cm-1 which are due to Cu-O stretching mode. Also, all the X-ray diffraction peaks could be readily assigned to those of crystalline CuO. The absence of any residual ligand traces or other phases in the FT-IR spectra and XRD patterns confirmed the preparation of high purity and single phase copper oxide nanoparticles. The TEM images show that the synthesized copper oxide nanoparticles are of plate like shape with average diameters of 10 – 20 nm. On the basis of the above results, the use of thiosemicarbazone ligands at the presence of suitable transition metal ions is potentially capable of forming other transition metal oxide nanoparticles by solid state thermal decomposition.

  10. Synthesis of high surface area nanometer magnesia by solid-state chemical reaction

    GUAN Hongbo; WANG Pei; ZHAO Biying; ZHU Yuexiang; XIE Youchang

    2007-01-01

    Nanometer MgO samples with high surface area,small crystal size and mesoporous texture were synthesized tion process accelerated the sintering of MgO,and MgO with calcining its precursor in flowing dry nitrogen at 520℃ for 4 h.The samples were characterized by X-ray diffraction,N2 adsorption,transmission electron microscopy,thermogravimetry,and differential thermal analysis.The as-prepared MgO was composed of nanocrystals with a size of about 4-5 nm and formed a wormhole-like porous structure.The MgO also had good thermal stability,and its surface areas remained at 357 and 153 m2.g-1 after calcination at 600 and 800℃ for 2 h,respectively.Compared with the MgO sample prepared by the precipitation method,MgO prepared by solid-state chemical reaction has uniform pore size distribution,surface area,and crystal size.The solid-state chemical method has the advantages of low cost,low pollution,and high yield,therefore it appears to be a promising method in the industrial manufacture of nanometer MgO.

  11. Exchange interactions of spin-active metallofullerenes in solid-state carbon networks

    Zaka, Mujtaba; Warner, Jamie H.; Ito, Yasuhiro; Morton, John J. L.; Rümmeli, Mark H.; Pichler, Thomas; Ardavan, Arzhang; Shinohara, Hisanori; Briggs, G. Andrew D.

    2010-02-01

    The electron paramagnetic resonance (EPR) of spin-active metallofullerenes (MFs) La@C82 and Sc@C82 diluted in solid-state C60 crystalline matrices with molar concentrations varying from 0.4% to 100% are investigated. For dilute concentrations, the hyperfine structure of the MFs is resolved, and as the concentration increases exchange narrowing is observed leading to a single peak in the EPR. Sc@C82 MFs are inserted into single-walled carbon nanotubes to form peapods with concentrations of 10% and 0.1%, diluted with C60 . For the case of peapods containing 10% Sc@C82 a strong narrow peak is observed in X -band CW EPR, but not pulsed measurements. Peapods containing Ce@C82 MFs are prepared and these also show similar CW EPR to the Sc@C82 , indicating the peak arises from charge transfer with the SWNT.

  12. Enzyme activities and substrate degradation by fungal isolates on cassava waste during solid state fermentation.

    Pothiraj, C; Eyini, M

    2007-12-01

    The growth and bioconversion potential of selected strains growing on cassava waste substrate during solid state fermentation were assessed. Rhizopus stolonifer showed the highest and the fastest utilization of starch and cellulose in the cassava waste substrate. It showed 70% starch utilization and 81% cellulose utilization within eight days. The release of reducing sugars indicating the substrate saccharification or degradation potential of the organisms reached the highest value of 406.5 mg/g by R. stolonifer on cassava waste during the eighth day of fermentation. The protein content was gradually increased (89.4 mg/g) on the eighth day of fermentation in cassava waste by R. stolonifer. The cellulase and amylase activity is higher in R. stolonifer than A. niger and P. chrysosporium. The molecular mass of purified amylase and cellulase seemed to be 75 KDal, 85 KDal respectively. PMID:24015097

  13. Synthesis of Ba{sub 0}.75Sr{sub 0}.25Al{sub 2}Si{sub 2}O{sub 8} - ZrO{sub 2} Ceramic Composites by Solid State Reaction of Mechanically Activated Precursor Mixtures

    Ramos-Ramirez, M. V.; Lopez-Cuevas, J.; Rodriguez-Galicia, J. L.; Rendon-Angeles, J. C.

    2014-07-01

    Precursor mixtures composed of fly ash, BaCO{sub 3}, SrCO{sub 3}, Al{sub 2}O{sub 3} and ZrO{sub 2}, were subjected to attrition milling for 0-8 h and then uniaxially pressed and sintered at 900-1500 degree centigrade/5 h, for the in situ solid state synthesis of composites with nominal Ba{sub 0}.75Sr{sub 0}.25Al{sub 2}Si{sub 2}O{sub 8} (SBAS)/ZrO{sub 2} mass ratios of: 1) 90/10, 2) 70/30, and 3) 50/50. Mechanical activation, combined with the likely generation of a considerable amount of transient liquid during sintering of the composites, notably enhanced the reactivity of the precursor mixtures. ZrO{sub 2} decreased the conversion from the hexagonal (Hexacelsian) into the monoclinic (Celsian) phases of SBAS in the composites, which became more pronounced when the content of ZrO{sub 2} was increased in the materials. Nearly full conversions could be achieved at temperatures as low as 1100 degree centigrade, by mechanically activating the precursor mixtures for times that increased with increasing content of ZrO{sub 2} in the materials. An increment in the time of mechanical activation of the precursor mixtures, as well as in their ZrO{sub 2} content and in the sintering temperature, increased the mechanical properties of the synthesized materials. Thus, the best mechanical properties were obtained for composition 3 milled for 8 h and sintered at 1500 degree centigrade. (Author)

  14. Synthesis, characterization and thermal behavior of solid state compounds of heavy trivalent lanthanide succinates

    Highlights: ► Thermal stability of compounds was investigated. ► Determination of the gaseous products released. ► The results also provided information concerning the denticity of the ligand. - Abstract: Solid-state Ln–L compounds, where Ln stands for heavy trivalent lanthanides or yttrium(III) (Tb–Lu, Y) and L is succinate, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), infrared spectroscopy, TG-DTA coupled to FTIR, elemental analysis, X-ray powder diffractometry and complexometry were used to characterize and study the thermal behavior of these compounds. For the terbium to thulium and yttrium compounds, the dehydration, as well the thermal decomposition of the anhydrous compound occurs in two consecutive steps, while ytterbium and lutetium the dehydration occurs in a single step. The results also led to information about the ligand's denticity, thermal stability and thermal decomposition of these compounds

  15. Solid State Reaction Synthesis and Thermoelectric Properties of Mg2Si doped with Sb and Te

    2002-01-01

    Doped with Sb and Te,Mg2Si based compounds were prepared respectively by solid state reaction at 823K for 8h.Effects of dopants of Sb and Te on the structure and thermoelectric properties of the compounds were investigated.By calculating the values of the electrical conductivity for Sb-doped sample,the mechanism of electric conduction at 625K is different.The figure of merit for sample doped with 0.4wt% Te at 500K is 2.4×10-3W/mK2,and it reaches 3.3×10-3W/mK2 at 650K for the sample doped with 0.5wt% Sb.The values are more than 1.4 times and 2.3 times of the pure Mg2Si sample.

  16. Novel protocol for the solid-state synthesis of magnetite for medical practices

    Paiva, D. L.; Andrade, A. L., E-mail: angelala01@hotmail.com [Federal University of Ouro Preto (UFOP), Department of Chemistry, ICEB (Brazil); Pereira, M. C. [Federal University of the Jequitinhonha and Mucuri Valleys (UFVJM), Institute of Science, Engineering and Technology (Brazil); Fabris, J. D., E-mail: jdfabris@ufmg.br [Federal University of the Jequitinhonha and Mucuri Valleys (UFVJM) (Brazil); Domingues, R. Z. [Federal University of Minas Gerais (UFMG), Department of Chemistry, ICEx (Brazil); Alvarenga, M. E. [Federal University of Ouro Preto (UFOP), Department of Chemistry, ICEB (Brazil)

    2015-06-15

    It is reported a novel approach to prepare nanoparticles of magnetite (Fe{sub 3}O{sub 4}) by heating a mixture of synthetic commercial maghemite (γFe{sub 2}O{sub 3}) with sucrose. This solid-state reaction leads to the chemical reduction of part of the Fe{sup 3+} of the precursor oxide to render Fe{sup 2+} and Fe{sup 3+} in octahedral and Fe{sup 3+} in tetrahedral sites of the Fe-O coordination framework. Powder X-ray diffraction patterns, FTIR and 298 K Mössbauer spectra confirm the conversion of maghemite into magnetite. Based on these results, the optimal sucrose:maghemite rate was found to be 4.

  17. Large scale synthesis and formation mechanism of silver nanoparticles in solid-state reactions at ambient temperature

    Highlights: • AgNPs were prepared by solid state reaction at ambient temperature. • Only silver nitrate and ascorbic acid were needed in this reaction. • The size of the AgNPs can be tuned conveniently. • Formation mechanism of the AgNPs was investigated. - Abstract: A one-step strategy for preparing Ag nanoparticles (AgNPs) on large scale is demonstrated successfully, based on solid-state reactions at ambient temperature. The environmentally friendly synthesis can be achieved by simply grinding AgNO3 and ascorbic acid (AA) for about 30 min without adding any solvent and organic protectors. The size of AgNPs can be readily controlled by adjusting the reaction parameters such as AgNO3/AA molar ratio and reaction time. The nanostructures of AgNPs and their formation mechanism have been also investigated with XRD, FTIR, FESEM, HRTEM and HPLC–MS. It was found that AA can reduce Ag+ into Ag0 to form AgNPs directly in accompanying with its first oxidation into 2,3-diketogulonic acid (2,3-DKG) and then a series of fragmentary species of 2,3-DKG

  18. Large scale synthesis and formation mechanism of silver nanoparticles in solid-state reactions at ambient temperature

    Zhang, Aiqin, E-mail: zhangaiqin@zzuli.edu.cn [State Laboratory of Surface and Interface Science and Technology, Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Tian, Yakun; Xiao, Yuanhua; Sun, Yuan [State Laboratory of Surface and Interface Science and Technology, Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Li, Feng [State Laboratory of Surface and Interface Science and Technology, Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); American Advanced Nanotechnology, Houston, TX 77459 (United States)

    2015-07-15

    Highlights: • AgNPs were prepared by solid state reaction at ambient temperature. • Only silver nitrate and ascorbic acid were needed in this reaction. • The size of the AgNPs can be tuned conveniently. • Formation mechanism of the AgNPs was investigated. - Abstract: A one-step strategy for preparing Ag nanoparticles (AgNPs) on large scale is demonstrated successfully, based on solid-state reactions at ambient temperature. The environmentally friendly synthesis can be achieved by simply grinding AgNO{sub 3} and ascorbic acid (AA) for about 30 min without adding any solvent and organic protectors. The size of AgNPs can be readily controlled by adjusting the reaction parameters such as AgNO{sub 3}/AA molar ratio and reaction time. The nanostructures of AgNPs and their formation mechanism have been also investigated with XRD, FTIR, FESEM, HRTEM and HPLC–MS. It was found that AA can reduce Ag{sup +} into Ag{sup 0} to form AgNPs directly in accompanying with its first oxidation into 2,3-diketogulonic acid (2,3-DKG) and then a series of fragmentary species of 2,3-DKG.

  19. Solid-state synthesis and magnetic properties of epitaxial FePd3(0 0 1) films

    The solid-state synthesis of magnetically soft phase FePd3 in epitaxial Pd(0 0 1)/Fe(0 0 1)/MgO(0 0 1) film systems was studied experimentally. The system had a Fe to Pd ratio of 1:3. An increase to 450 °C leads to the formation of three variants of ordered L10-FePd crystallites. At 500 °C, the solid-state reaction of unreacted Pd with L10-FePd crystallites initiates the growth of an ordered epitaxial L12-FePd3(0 0 1) layer. When annealing at 650 °S, a gradual disordering is observed. The magnetic anisotropy (K1=−2.0×103 erg/cm3) and the saturation magnetization (MS=650 emu/cm3) of the disordered FePd3 phase were determined. - Highlights: ► We investigated phase transformations in epitaxial Pd(0 0 1)/Fe(0 0 1) bilayers. ► The successive formation of L10-FePd and L12-FePd3 ordered phases was observed. ► The FePd3 epitaxial orientation relationship with substrate MgO(0 0 1) was identified. ► FePd3 is a magnetically soft phase with coercivity (HC<1 Oe).

  20. Bioconversion and enzymatic activities of neurospora sitophila grown under solid state and submerged fermentation on Sago Hamps

    N.Sitophila was grown under controlled conditions of solid state and submerged fermentation on Sago Hampas. The optimum conditions of protein enrichment previously established for sugar beet pulp was used for this study. Under this condition the protein content of Sago Hampas under solid state increased from 1.4 to 14.45% (W/W) whereas for Sago Hampas and Sago starch, the protein content under submerged condition increased from 1.4% (W/W) and 0.7% (W/W) to 18.56% (W/W) and 43/16% (W/W) based on dry weight of product respectively. The cellulase, a-amylase and glucoamylase activities of N.Sitophila under solid state condition on Sago Hampas were, 9.0, 0.6 and 11.8 U/g of wet fermented solid respectively. the enzymatic activities were also measured under submerged fermentation using both Sago Hampas and Sago starch as substrate

  1. Cellulase Activity in Solid State Fermentation of Palm Kernel Cake with Trichoderma sp.

    Massaud, M. B. N.

    2012-01-01

    Full Text Available Aims: The effect of different types of fungal inocula to the cellulase activity measured on palm kernel cake (PKC was studied. Methodology and Results: Isolate Pro-A1 which was identified as Trichoderma sp. was selected as a potential producer of cellulase via solid state fermentation technique (SSF. Two types of PKCs were used; raw PKC (containing residual oil and defatted PKC. The PKCs were inoculated with different concentrations of conidia and varying amounts (g of solid mycelia plugs (SMP for SSF. The effect of ultrafiltered crude fungal filtrate (CFF as inocula was also being tested. The highest cellulase activity of 2.454 FPU/mL was detected with 60% (wt/wt SMP applied to the raw PKC. Conversely, 2.059 FPU/mL of cellulase activity was measured when 80% (wt/wt of SMP was applied to the defatted PKC which is 62.3% higher than the untreated defatted PKC; and more than 100% increase in enzymatic activity compared to raw PKC. The cellulase activity in the SSF inoculated with 8 x 106 conidia /mL and 12 x 106 conidia /mL were 1.704 FPU/mL for raw PKC and 1.856 FPU/mL for defatted PKC, an enhancement of about 46% from uninoculated batch. Inoculation with CFF bears corresponding maximum improvement of the cellulase activity on both PKCs of 13.58% (raw and 2.86% (defatted. Conclusion, significance and impact of study: The current study proves that Trichoderma sp. in the form of SMP can enhance the cellulase activity on PKCs effectively with more than 100% increment. Fungal conidia are also a better choice in enhancing cellulase activity of Trichoderma sp. permitted that the PKC used is devoid of oil. From this study, Trichoderma sp. holds the potential of converting lignocellulosic materials into products of commercial and industrial values such as glucose and other biofuels.

  2. The Effect of Cellulose Crystal Structure and Solid-State Morphology on the Activity of Cellulases

    Stipanovic, Arthur J [SUNY College of Environmental Science and Forestry

    2014-11-17

    Consistent with the US-DOE and USDA “Roadmap” objective of producing ethanol and chemicals from cellulosic feedstocks more efficiently, a three year research project entitled “The Effect of Cellulose Crystal Structure and Solid-State Morphology on the Activity of Cellulases” was initiated in early 2003 under DOE sponsorship (Project Number DE-FG02-02ER15356). A three year continuation was awarded in June 2005 for the period September 15, 2005 through September 14, 2008. The original goal of this project was to determine the effect of cellulose crystal structure, including allomorphic crystalline form (Cellulose I, II, III, IV and sub-allomorphs), relative degree of crystallinity and crystallite size, on the activity of different types of genetically engineered cellulase enzymes to provide insight into the mechanism and kinetics of cellulose digestion by “pure” enzymes rather than complex mixtures. We expected that such information would ultimately help enhance the accessibility of cellulose to enzymatic conversion processes thereby creating a more cost-effective commercial process yielding sugars for fermentation into ethanol and other chemical products. Perhaps the most significant finding of the initial project phase was that conversion of native bacterial cellulose (Cellulose I; BC-I) to the Cellulose II (BC-II) crystal form by aqueous NaOH “pretreatment” provided an increase in cellulase conversion rate approaching 2-4 fold depending on enzyme concentration and temperature, even when initial % crystallinity values were similar for both allomorphs.

  3. Synthesis of Cu/CuO nanoparticles in mesoporous material by solid state reaction

    Sohrabnezhad, Sh.; Valipour, A.

    2013-10-01

    The Mobil Composition of Matter No. 41 (MCM-41) containing 1.0 and 5.0 wt.% of Cu was synthesized under solid state reaction. The calcinations of samples were done at two different temperatures, 500 and 300 °C. X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) were used for samples characterization. Powder X-ray diffraction showed that when Cu(CH3COO)2 content is about 1.0 wt.% in Cu/MCM-41, the guest CuO-NPs and copper ions is formed on the silica channel wall, and more exists in the crystalline state. When Cu(CH3COO)2 content exceeds this value (5.0 wt.%), CuO nanoparticles and Cu2+ ions can be observed in low crystalline state. From the diffuse reflectance spectra it was confirmed that 5 wt.% Cu/MCM-41 sample calcined at 500 °C show plasmon resonance band due to Cu nanoparticles in the range between 500 and 600 nm and small copper clusters Cun in 450 nm. It also shows that some of the Cu2+ ions are present octahedrally in extraframework position in all samples. Both fourier transform infrared and diffuse reflectance spectra indicate that some of Cu2+ ions are tetrahedrally within the framework position in 1 wt.% Cu/MCM-41 samples. TEM images indicated that nanoparticles size of CuO is in range of 30-40 nm.

  4. Production and regulation of lipase activity from Penicillium restrictum in submerged and solid-state fermentations.

    de Azeredo, Luciana A I; Gomes, Patrícia M; Sant'Anna, Geraldo L; Castilho, Leda R; Freire, Denise M G

    2007-05-01

    Different carbon (C) sources, mainly carbohydrates and lipids, have been screened for their capacity to support growth and lipase production by Penicillium restrictum in submerged fermentation (SmF) and in solid-state fermentation (SSF). Completely different physiological behaviors were observed after the addition of easily (oleic acid and glucose) and complex (olive oil and starch) assimilable C sources to the liquid and solid media. Maximal lipolytic activities (12.1 U/mL and 17.4 U/g) by P. restrictum were obtained with olive oil in SmF and in SSF, respectively. Biomass levels in SmF (12.2-14.1 mg/mL) and SSF (7.0-8.0 mg/g) did not varied greatly with the distinct C sources used. High lipase production (12.3 U/g) using glucose was only attained in SSF, perhaps due to the ability of this fermentation process to minimize catabolite repression. PMID:17457647

  5. Levansucrase optimization using solid state fermentation and levan biological activities studies.

    Esawy, Mona A; Abdel-Fattah, Azza M; Ali, Mamdouh M; Helmy, Wafaa A; Salama, Bassem M; Taie, Hanan A A; Hashem, Amal M; Awad, Ghada E A

    2013-07-01

    Bacillus subtilis NRC1aza produced levansucrase under solid state fermentation using starch as support. A sequential optimization strategy, based on statistical experimental designs is employed to enhance enzyme productivity. First, a 2-level Plackett-Burman design was applied for bioprocess parameters screen that significantly increase levansucrase production. Second optimization step was performed using fractional factorial design in order to optimize the amounts of highest positive variables that had significant effect on levansucrase productivity. Maximal enzyme productivity of 170 U/gds was achieved in presence of glucose, yeast extract, and pH 8. In vitro, experiments confirmed that LevCR and LevQT had an antitumor activity against different animal and human cancer cell lines by demonstrating inhibitory effects on growth of Ehrlich ascites carcinoma cell line, human MCF-7 breast and liver HepG2 cancer cell lines, in particular LevQT was found to be efficacious compared to anticancer drug, cisplatin. Result focused in LevCR as strong fibrinolytic agent. PMID:23688489

  6. Spiropyran salts and their neutral precursors: synthesis, crystal structure, photochromic transformations in solutions and solid state

    Yurieva, E. A.; Aldoshin, S. M.

    2015-06-01

    This review covers investigations of spiropyran iodides with N-substituted indoline fragment, and with the pyran cycle being annelated to N-methylated pyridine ring. The schemes of synthesis of iodides and their neutral precursors, as well as results of X-ray analysis and photochemical study of the crystals of the obtained compounds are presented. Based on our and literature data, the relationship between the structure and photochromic properties has been discussed for a series of salts and neutral pyridospiropyrans.

  7. Low-temperature solid-state synthesis and optical properties of ZnO/CdS nanocomposites

    Highlights: • Using a low-temperature solid-state method, ZnO/CdS nanocomposites were obtained • Grain growth kinetics of cubic CdS and hexagonal ZnO phase was described. • Sufficient grinding and heating treatment was a key for formation of composites. • Optical properties could be easily manipulated by reaction temperature and time. - Abstract: A simple low-temperature solid-state reaction in the presence of the surfactant PEG400 was developed to obtain ZnO/CdS nanocomposites. The effects of synthesis temperature and reaction time on crystal structure and optical properties of the nanocomposites were investigated by several technologies. X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) characterizations showed that the products consisted of the nanoparticles, and the grain growth kinetics of the cubic CdS and the hexagonal ZnO phase in the nanocomposites was described. The mechanism analysis suggested that sufficient grinding and heating treatment was a key to form the ZnO/CdS nanocomposites, and the surfactant PEG400 was proved not to involve the reaction and prevent the nanoparticles from aggregating to larger in whole grinding and heat-treatment process. Ultraviolet–visible (UV–vis) spectra revealed that the band gaps of the nanocomposites could be tuned by the reaction temperature and reaction time. Photoluminescence (PL) spectra showed that the changing position and the intensity of the emission peaks resulted from the rate of electron transfer and recombination probability under the different conditions

  8. Synthesis of single phase cubic Al-substituted Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} by solid state lithiation of mixed hydroxides

    Langer, Frederieke; Glenneberg, Jens [University of Bremen, Innovative Sensor and Functional Materials Research Group, Badgasteiner Str. 1, 28359 Bremen (Germany); Bardenhagen, Ingo [Fraunhofer Institute for Manufacturing Technology and Advanced Materials – IFAM, Wiener Str. 12, 28359 Bremen (Germany); Kun, Robert, E-mail: robert.kun@uni-bremen.de [University of Bremen, Innovative Sensor and Functional Materials Research Group, Badgasteiner Str. 1, 28359 Bremen (Germany); Fraunhofer Institute for Manufacturing Technology and Advanced Materials – IFAM, Wiener Str. 12, 28359 Bremen (Germany)

    2015-10-05

    Highlights: • Soft chemistry synthesis of pure phase cubic-LLZ solid electrolyte. • Solid state lithiation of hydroxide precipitates. • Homogeneous distribution of constituting elements in the product. • Temperature dependent Li-ion conductivity of the LLZ was characterized. - Abstract: Substituted Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} (LLZ) with cubic garnet type structure is a promising candidate for solid state electrolyte in all-solid-state batteries. Here we present a novel synthesis route to obtain single phase cubic Al-substituted LLZ. The two step method consists of a co-precipitation of metal hydroxides from aqueous solution as well as solid-state lithiation and crystallization of the dried precipitate. Morphology and chemical composition of precipitated particles were investigated with SEM and EDS. Phase composition of calcined powder was confirmed to be pure phase cubic LLZ via XRD. The temperature dependent lithium ion conduction of a sintered pellet was determined to be 6.3 · 10{sup −5} S/cm at 353 K with an activation energy of 0.58 eV.

  9. Mechanochemically assisted room temperature solid state metathesis reaction for the synthesis of MMoO4 (M = Ca, Sr and Ba)

    Purnendu Parhi; Satya Sadhan Singh; Alok R Ray; A Ramanan

    2006-04-01

    This communication reports a novel mechanochemically assisted room temperature solid state metathesis reaction for the synthesis of submicron-size alkaline-earth molybdates crystallizing in a tetragonal Scheelite structure. The solids were characterized by powder XRD, FTIR, TGA, DTA, SEM, EDAX and TEM to ascertain their composition, phase homogeneity and morphology.

  10. Solid state theory

    Harrison, Walter A

    2011-01-01

    ""A well-written text . . . should find a wide readership, especially among graduate students."" - Dr. J. I. Pankove, RCA.The field of solid state theory, including crystallography, semi-conductor physics, and various applications in chemistry and electrical engineering, is highly relevant to many areas of modern science and industry. Professor Harrison's well-known text offers an excellent one-year graduate course in this active and important area of research. While presenting a broad overview of the fundamental concepts and methods of solid state physics, including the basic quantum theory o

  11. Enhancement of wheat grain antioxidant activity by solid state fermentation with Grifola spp.

    Postemsky, Pablo; Curvetto, Néstor

    2014-05-01

    Grifola frondosa, Grifola gargal, and Grifola sordulenta are edible and medicinal mushrooms with antioxidant properties. To obtain wheat flour (Wf ) with a higher antioxidant activity than the one exhibited by regular Wf, solid state fermentation (SSF) of wheat grains with mycelia of those Grifola spp. was used to obtain biotransformed wheat grain (BWG) flour. The methanolic extract of control Wf and BWG flour of G. gargal, G. sordulenta, and G. frondosa (GfWG, GgWG, and GsWG, respectively) were studied for their radical scavenging (RS) activity against 2,2-diphenyl-1-picrylhydracyl (DPPH) and their Fe(III) reducing power (RP). The values for RS-EC50 decreased in BWG flour, therefore presenting a higher antioxidant activity: GgWG (0.56 mg/mL), GfWG (0.81 mg/mL), and GsWG (5.80 mg/mL) in comparison to Wf (57.60 mg/mL). The antioxidant content for this RS activity in terms of ascorbic acid content (RS-EQAA) was highest in GfWG, followed by GgWG and GsWG (71.73, 14.46, and 3.02 mg/g, respectively) and lowest in Wf (0.25 mg/g). The RP-EC50 values in GgWG, GfWG, and GsWG were low (0.55, 0.64, and 4.20 mg/mL, respectively) with respect to Wf (55.00 mg/mL). Compared with Wf (0.56 mg/g), the RP capacity in terms of ascorbic acid content (RP-EQAA) was very high in GfWG (193.67 mg/g) followed by GgWG and GsWG (31.42 and 8.74 mg/g, respectively). The high content in gallic acid equivalents was consistent with RS-EQ(AA) and RP-EQ(AA) contents. TLC revealed that antioxidant activity in BWG could be related to the presence of phenolic compounds. Thus, a valuable food alternative can easily be obtained with wheat grains, that is, by markedly increasing their antioxidant value through SSF with Grifola spp. PMID:24552201

  12. Synthesis of oxide and spinel nanocrystals for use in solid state lighting

    Foley, Megan Elizabeth

    In this dissertation, microwave chemistry is employed to synthesize a variety of different crystalline nanoparticles (NPs). This introduction will describe the structures, properties and applications of the NPs studied within the dissertation, with a main focus being on ligand sensitization for the goal of enhanced luminescence. The use of metal acetylacetonate complexes to make Europium (III) doped Ytrrium (Y2O3) NPs is explored, where the acetylacetonate acts both as a source of oxygen for the synthesis of Y2O3, as well as an organic chromophore acting as an "antenna" for the absorption of light and subsequent excitation transfer to the incorporated Europium (III) (Chapter 2). Other host materials are investigated by method of metal acetylacetonate decomposition to synthesize a variety of different nanospinels, having the general formula AB2X4, with sulfide variants made by decomposition of diethyldithiocarbamate, (Chapter 3). The antenna ligand thenoyltrifluoroacetone (tta), which is known to undergo a Dexter energy transfer (DET) mechanism to efficiently sensitize Europium (III) emission, is used to determine the distance of energy transfer in Europium (III) doped nanospinels by passivating the surface of the nanospinel with a tta (Chapter 4). A variety of ligands are explored in order to optimize the sensitization efficiency in relation to the difference in energy between the singlet and triplet levels of the ligands versus the 5D0 and 5D4 energy levels of Europium (III) and Terbium (III) respectively (Chapter 5).

  13. Effect of precursors on the solid-state synthesis of semiconducting PbS nanostructures

    Sujata Kasabe

    2013-03-01

    Full Text Available In this communication, we report facile and economical in-situ preparation of lead sulphide (PbS nanorods and nanocubes within the Polyphenylene sulphide (PPS matrix. PPS plays a dual role in the synthesis of the resultant nanostructures as - (i a chalcogen source and (ii a stabilizing matrix. We studied the effect of change of lead precursor from lead nitrate to acetate on the morphological properties of the resultant nanostructures. The effect of molar ratios of the reactants (1:1, 1:5, 1:10, 1:15 and 1:20 on the morphology of the products was also studied. The resultant nanocomposites were characterized by various physico-chemical techniques like X-ray Diffractometry (XRD, SEM equipped with EDAX, TEM and UV-Visible spectroscopy. The prima-facie observations suggest effective formation and subsequent entrapment of lead sulphide nanorods and nanocubes, respectively, when lead acetate and lead nitrate precursors were used. Additionally, simultaneous occurrence of nanocrystalline cubic lead as an impurity phase is noticed in case of heated admixtures for both the precursors.

  14. Enzyme Activities and Substrate Degradation by Fungal Isolates on Cassava Waste During Solid State Fermentation

    Pothiraj, C.; Eyini, M.

    2007-01-01

    The growth and bioconversion potential of selected strains growing on cassava waste substrate during solid state fermentation were assessed. Rhizopus stolonifer showed the highest and the fastest utilization of starch and cellulose in the cassava waste substrate. It showed 70% starch utilization and 81% cellulose utilization within eight days. The release of reducing sugars indicating the substrate saccharification or degradation potential of the organisms reached the highest value of 406.5 m...

  15. Solid state synthesis and structural refinement of polycrystalline LaCa1-TiO3 ceramic powder

    O P Shrivastava; Narendra Kumar; I B Sharma

    2004-04-01

    Perovskite structure based ceramic precursors have a characteristic property of substitution in the ``A" site of the ABO3 structure. This makes them a potential material for nuclear waste management in synthetic rock (SYNROC) technology. In order to simulate the mechanism of rare earth fixation in perovskite, La Ca1-TiO3 (where = 0.05) has been synthesized through ceramic route by taking calculated quantities of oxides of Ca, Ti and La as starting materials. Solid state synthesis has been carried out by repeated pelletizing and sintering the finely powdered oxide mixture in a muffle furnace at 1050°C. The ceramic phase has been characterized by its powder diffraction pattern. Step analysis data has been used to determine the structure of solid solution of lanthanum substituted calcium titanate. The SEM and EDAX analyses also confirm that the CaTiO3 can act as a host for lanthanum. X-ray data has been interpreted using CRYSFIRE and POWDERCELL softwares. The ℎ, , values for different lattice planes have been generated from the experimental data. The lanthanum substituted perovskite crystallizes in orthorhombic symmetry with space group (#62). Following unit cell parameters have been calculated: = 5.410, = 7.631, = 5.382. The calculated and observed values of corresponding intensities, 2, and density show good agreement. GSAS based calculation for bond distances Ti–O, Ca–O, La–O and bond angles Ti–O–Ca, Ca–O–Ca, La–O–Ti have been reported.

  16. Synthesis of monoclinic Celsian from Coal Fly Ash by using a one-step solid-state reaction process

    Long-Gonzalez, D.; Lopez-Cuevas, J.; Gutierrez-Chavarria, C.A.; Pena, P.; Baudin, C.; Turrillas, X. [CINVESTAV, Coahuila (Mexico)

    2010-03-15

    Monoclinic (Celsian) and hexagonal (Hexacelsian) Ba1-xSrxAl{sub 2}Si2O8 solid solutions, where x=0, 0.25, 0.375, 0.5, 0.75 or 1, were synthesized by using Coal Fly Ash (CFA) as main raw material, employing a simple one-step solid-state reaction process involving thermal treatment for 5 h at 850-1300{sup o}C. Fully monoclinic Celsian was obtained at 1200{sup o} C/5 h, for SrO contents of 0.25 {<=} x {<=} 0.75. However, an optimum SrO level of 0.25 {<=} x {<=} 0.375 was recommended for the stabilization of Celsian. These synthesis conditions represent a significant improvement over the higher temperatures, longer times and/or multi-step processes needed to obtain fully monoclinic Celsian, when other raw materials are used for this purpose, according to previous literature. These results were attributed to the role of the chemical and phase constitution of CFA as well as to a likely mineralizing effect of CaO and TiO{sub 2} present in it, which enhanced the Hexacelsian to Celsian conversion.

  17. Solid-state synthesis and thermoelectric properties of Cr-doped MnSi{sub 1.73}

    Shin, Dong-Kil; You, Sin-Wook; Kim, Il-Ho [Korea National University of Transportation, Chungju (Korea, Republic of)

    2014-11-15

    Cr-doped HMSs (higher manganese silicides), MnSi{sub 1.73} : Cr{sub x} (x = 0, 0.005, 0.01, 0.02, 0.03), were prepared by using a solid-state reaction and hot pressing. X-ray diffraction analysis and Rietveld refinement confirmed the synthesis of MnSi{sub 1.73}. The Cr atoms were confirmed to be soluble in the HMS structure because the lattice constant increased with increasing Cr content (x), and the solid solubility limit of Cr was estimated as x = 0.01. All specimens showed p-type conduction and exhibited degenerate semiconductor characteristics at all temperatures examined (323 - 823 K). The Seebeck coefficient was decreased and the electrical conductivity was increased by Cr doping. The dimensionless thermoelectric figure of merit ZT was obtained as 0.36 at 823 K for MnSi{sub 1.73} : Cr{sub 0.005} and MnSi{sub 1.73} : Cr{sub 0.01} because the power factor was increased and the thermal conductivity was decreased by Cr doping.

  18. Synthesis, photophysics of two new perylene bisimides and their photovoltaic performances in quasi solid state dye sensitized solar cells

    Mikroyannidis, John A.; Stylianakis, Minas M. [Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR-26500 Patras (Greece); Roy, M.S. [Defence Laboratory, Jodhpur 342011 (Raj.) (India); Suresh, P.; Sharma, G.D. [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur 342005 (Raj.) (India)

    2009-12-01

    Two new symmetrical compounds A and P based on perylene-anthracene and perylene-pyrene, respectively, were synthesized and characterized by FT-IR, {sup 1}H NMR, TGA and TMA. These compounds contained tert-butyl groups which enhanced their solubility, decomposed above 400 C and gave char yields of 46-65% at 800 C in N{sub 2}. Compound A showed significantly higher glass transition temperature (124 C) than P (75 C). Their absorption spectra were broad with longer wavelength absorption at 467-525 nm and optical band gap of 2.05 eV. The solutions of the compounds emitted green-yellow light with maximum at 555 nm, while their films were not photoluminescent. The compound A shows better photovoltaic response than compound P. Quasi solid state dye sensitized solar cells (DSSCs) have been fabricated employing compound A as sensitizer and polymer sol gel as electrolyte and characterized through the current-voltage characteristics in dark as well as under illumination and electrochemical impedance spectra. We found that the Al{sub 2}O{sub 3} modification of TiO{sub 2} layer significantly improves the dye absorption resulting in enhancement of power conversion efficiency (PCE) (from 1.15 to 2.13%) which is attributed to the increase in electron lifetime and reduction in back transfer of electrons. Finally, the TiO{sub 2} has been incorporated into the polymer electrolyte gel to improve the power conversion efficiency (3.42%) of the quasi solid state DSSC. The faster electron diffusion in the device, the high ionic conductivity and the low activation energy of the polymer electrolyte are also responsible for enhanced PCE, when TiO{sub 2} nano-particles are incorporated in the polymer electrolyte. (author)

  19. Solid state synthesis of chitosan and its unsaturated derivatives for laser microfabrication of 3D scaffolds

    Akopova, T. A.; Demina, T. S.; Bagratashvili, V. N.; Bardakova, K. N.; Novikov, M. M.; Selezneva, I. I.; Istomin, A. V.; Svidchenko, E. A.; Cherkaev, G. V.; Surin, N. M.; Timashev, P. S.

    2015-07-01

    Chitosans with various degrees of deacetylation and molecular weights and their allyl substituted derivatives were obtained through a solvent-free reaction under shear deformation in an extruder. Structure and physical-chemical analysis of the samples were carried out using nuclear magnetic resonance (NMR), ultraviolet (UV) and infrared radiation (IR) spectroscopy. Photosensitive materials based on the synthesized polymers were successfully used for microfabrication of 3D well-defined architectonic structures by laser stereolithography. Study on the metabolic activity of NCTC L929 cultured in the presence of the cured chitosan extracts indicates that the engineered biomaterials could support adhesion, spreading and growth of adherent-dependent cells, and thus could be considered as biocompatible scaffolds.

  20. Summarizing report on research and development activities in 1989, KfK Institute of Materials and Solid State Research

    This annual report of the Institute for Materials and Solid State Research (IMF) summarizes the institute's activities in the following fields and projects: 1) Fast Breeder project, PSB. Work here concentrated on core, cladding, and structural materials, safety analyses, and core monitoring. 2) Nuclear Fusion Project, PKF, (structural materials, superconducting magnets, blanket development). 3) Radioactive Waste Processing (PWA) and waste management (analysis of residues from dissolution of LWR fuels in nitric acid; materials testing of an austenitic steel in HNO3). 4) Ultimate disposal of radioactive waste (corrosive testing of materials for HAW containers). 5) Environment and safety (mechanical and chemical behaviour of LWR fuel elements at high temperatures). 6) Materials and solid state research (high-temperature materials, ceramics, superconducting materials). An annex to the annual report presents the bibliographic data of all reports and other publications written by members of the institute. (MM)

  1. Kinetic Studies on the Synthesis of Monoclinic Li3V2(PO4)3 via Solid-State Reaction.

    Chen, Shanhua; Wu, Jun; Su, Zelong; Deng, Ling

    2014-05-14

    The data obtained by thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (XRD) measurements of the stoichiometric mixture of LiNO3, NH4VO3, and NH4H2PO4 were analyzed by both the Flynn-Wall-Ozawa (FWO) and Friedman-Reich-Levi (FRL) methods. The whole solid state reaction process could be divided into four stages corresponding to α values of 0.03-0.20, 0.30-0.60, 0.70-0.80, and 0.90-0.99. The nucleation of LiVP2O7 (α = 0.70-0.80) is a determining step of the four-reaction processes, for which the mechanism of random nucleation and subsequent growth, described by the Avrami-Erofeev equation (n = 4) G(α) = [-ln(1 - α)](4), was assumed. Moreover, the Gibbs free energy of activation ΔG*, enthalpy of activation ΔH*, and entropy of activation ΔS* at maximum temperature of the peak for the determining step were 99.24 kJ·mol(-1), 199.97 kJ·mol(-1), and 136.30 J·mol(-1)·K(-1), respectively. Finally, XRD analyses confirmed that the Li3V2(PO4)3 synthesized by the precursor route is a pure phase. PMID:24806598

  2. Synthesis and solid state structures of Chalcogenide compounds of Imidazolin-2-ylidene-1,1-Diphenyl-phosphinamine

    Naktode Kishor; Suman Das; Abhinanda Kundu; Hari Pada Nayek; Tarun K Panda

    2016-03-01

    We report the synthesis and solid state structures of 1,3-di-aryl-imidazolin-2-ylidine-1,1-diphenylphosphinamine [(aryl=mesityl (1a) and aryl=2,6-diisopripyl (1b)] and their chalcogenide compounds 3-di-aryl-imidazolin-2-ylidine-P, P-diphenylphosphinicamide (2a,b), 1,3-di-aryl-imidazolin-2-ylidine-P,P diphenyl-phosphinothioicamide (3a,b) and 1,3-diaryl-imidazolin-2-ylidine-P,P -diphenyl-phosphinoselenoicamide (4a,b).The compounds 1a,b were prepared in good yield by the reaction of 1,3-di-aryl-imidazolin-2-imine and chlorodiphenylphosphine in the presence of triethylamine in toluene. The reactions of 1a,b with elemental sulphur and selenium afforded the corresponding chalcogenide compounds 3a,b and 4a,b respectively.The corresponding oxo- derivative (2a,b) was obtained by reacting compound 1a,b with 30% aqueous hydrogen peroxide in THF. The molecular structures of 1a, 2a, 3a and 4a,b have been established by single crystal X-ray diffraction analyses. The molecular structures reveal that even C1–N1–P1 angle (124.62o) in compound 1a is less obtuse compared to the corresponding C1–N1–Si1 angles (157.8o) observed in related N-silylated 2-iminoimidazolines and trimethylsilyl iminophosphoranes. C1–N1–P1 angles are further widened in compounds 2a, 3a, and 4a,b due to the attachment of chalcogen atoms onto phosphorus atom.

  3. Solid state chemistry and its applications

    West, Anthony R

    2013-01-01

    Solid State Chemistry and its Applications, 2nd Edition: Student Edition is an extensive update and sequel to the bestselling textbook Basic Solid State Chemistry, the classic text for undergraduate teaching in solid state chemistry worldwide. Solid state chemistry lies at the heart of many significant scientific advances from recent decades, including the discovery of high-temperature superconductors, new forms of carbon and countless other developments in the synthesis, characterisation and applications of inorganic materials. Looking forward, solid state chemistry will be crucial for the

  4. Measurement of volumic activities of radon in air in houses and in working rooms with solid state nuclear track detectors

    In this work, a new method of measuring volumic activity of radon has been developed. This method is based on using solid state nuclear track detectors LR-115 type II. It has been applied to measurement of volumic activities of radon in air in houses and in working rooms in different regions of Morocco. These measurements, carried out for the first time in the country, allowed to estimate the dose equivalents of radon received by the population of the studied regions. 59 refs., 38 figs., 38 tabs. (F.M.)

  5. Synthesis of Ca2 ZnSi2O7:Eu phosphor by a modified solid-state reaction and its luminescent properties

    WU Xiangmei; SONG Fenglan; HOU Qiaozhi

    2009-01-01

    This paper reports the detailed preparation and phosphorescence properties of Eu2+-activated Ca2 ZnSi2O7 phosphors by a modified solid-state reaction. Phase-pure crystalline Ca2ZnSi2O7 is obtained at 600℃, a much lower temperature than by conventional solid-state reaction and the preparation process of Ca2ZnSi2O7 is simple. The obtained phosphors showed three emission peaks at 480,580 and 620 nm,respectively. Auxiliary activator R3+(R=Dy, Nd, Tm) would enhance their luminescent properties.

  6. Thin-film solid state research activities at the Van de Graaff Group, NAC June 1991

    Thin-film solid state research was started at the National Accelerator Centre (NAC) at Faure in 1977. This work has since lead to fruitful collaboration with three local universities, the Peninsula Technicon, the Research Development and Implementation Group of the CSIR and several overseas laboratories. Sixty one publications have been published to date with 16 M.Sc. and 13 Ph.D. degrees awarded or still in progress. The favourable features of many nuclear techniques are being used at the NAC to study the metallization of devices, metal-metal interaction, laser processing, high energy ion-implantation and thin-film superconductors. The research that is being carried out at the NAC is of a basic nature and is as such important, not only for making semiconductor devices but also for thin film technology in general

  7. The synthesis and optical property of solid-state-prepared YAG:Ce phosphor by a spray-drying method

    Ce3+-activated yttrium aluminum garnet (Y3Al5O12:Ce, YAG:Ce) powder as luminescent phosphor was synthesized by the solid-state reaction method. The phase identification, microstructure and photoluminescent properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), absorption spectrum and photoluminescence (PL) analysis. Spherical phosphor particle is considered better than irregular-shaped particle to improve PL property and application, so this phosphor was granulated into a sphere-like shape by a spray-drying device. After calcinating at 1500 deg. C for 0, 4, and 8 h, the product was identified as YAG and CeO2 phases. The CeO2 phase content is decreased by increasing the calcination time or decreasing the Ce3+ doping content. The product showed higher emission intensity resulted from more Ce3+ content and larger grain size. The product with CeO2 was found to have lower emission intensity. This paper presents the crystal structures of Rietveld refinement results of powder XRD data

  8. Spatially-temporal dynamics of a passively Q-switched Raman-active solid-state oscillator

    Kalashnikov, V L; Yumashev, K V

    2009-01-01

    The spatially-temporal model of an all-solid-state passively Q-switched oscillator with an active medium providing the stimulated Raman scattering is presented. The model does not presume a Gaussian shape of the cylindrically symmetric modes at both fundamental and Stokes wavelengths. It is found, that the highly-nontrivial spatially-temporal dynamics can be regularized by the optimal choice of the oscillator parameters, viz. initial transmission of a saturable absorber, curvature of a spherical mirror, and output mirror transmission at the fundamental and Stokes wavelengths. As a result, the pulse can be substantially temporally squeezed and spatially broadened at both fundamental and Stokes wavelengths.

  9. Synthesis of PtNPs/AQ/Ru(bpy)3(2+) colloid and its application as a sensitive solid-state electrochemiluminescence sensor material.

    Du, Yan; Qi, Bin; Yang, Xiurong; Wang, Erkang

    2006-11-01

    The facile synthesis of the novel platinum nanoparticles/Eastman AQ55D/ruthenium(II) tris(bipyridine) (PtNPs/AQ/Ru(bpy)3(2+)) colloidal material for ultrasensitive ECL solid-state sensors was reported for the first time. The cation ion-exchanger AQ was used not only to immobilize ECL active species Ru(bpy)3(2+) but also as the dispersant of PtNPs. Colloidal characterization was accomplished by transmission electron microscopy (TEM), X-ray photoelectron spectrum (XPS), and UV-vis spectroscopy. Directly coating the as-prepared colloid on the surface of a glassy carbon electrode produces an electrochemiluminescence (ECL) sensor. The electronic conductivity and electroactivity of PtNPs in composite film made the sensor exhibit faster electron transfer, higher ECL intensity of Ru(bpy)3(2+), and a shorter equilibration time than Ru(bpy)3(2+) immobilized in pure AQ film. Furthermore, it was demonstrated that the combination of PtNPs and permselective cation exchanger made the sensor exhibite excellent ECL behavior and stability and a very low limit of detection (1 x 10(-15) M) of tripropylamine with application prospects in bioanalysis. This method was very simple, effective, and low cost. PMID:17064122

  10. Solid state synthesis and characterization of ferromagnetic nanocomposite Fe–In{sub 2}O{sub 3} thin films

    Myagkov, V.G. [Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036 (Russian Federation); Reshetnev Siberian State Aerospace University, Krasnoyarsk 660014 (Russian Federation); Tambasov, I.A., E-mail: tambasov_igor@mail.ru [Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036 (Russian Federation); Bayukov, O.A. [Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036 (Russian Federation); Zhigalov, V.S. [Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036 (Russian Federation); Reshetnev Siberian State Aerospace University, Krasnoyarsk 660014 (Russian Federation); Bykova, L.E. [Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036 (Russian Federation); Mikhlin, Yu.L. [Institute of Chemistry and Chemical Technology, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660049 (Russian Federation); Volochaev, M.N. [Reshetnev Siberian State Aerospace University, Krasnoyarsk 660014 (Russian Federation); Bondarenko, G.N. [Institute of Chemistry and Chemical Technology, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660049 (Russian Federation)

    2014-11-05

    Highlights: • Ferromagnetic Fe–In{sub 2}O{sub 3} nanocomposites were prepared by solid-state reactions. • The reaction starts above the initiation temperature T{sub in} ∼ 180 °S. • The reaction products contain α-Fe nanocrystals enveloped by an In{sub 2}O{sub 3} shell. • The formation mechanisms of the Fe–In{sub 2}O{sub 3} core/shell-like structures were discussed. - Abstract: We have successfully synthesized ferromagnetic Fe–In{sub 2}O{sub 3} nanocomposite thin films for the first time using the thermite reaction Fe{sub 2}O{sub 3} + In = In{sub 2}O{sub 3} + Fe. The initial In/Fe{sub 2}O{sub 3} bilayers were obtained by the deposition of In layers on α-Fe{sub 2}O{sub 3} films. The reaction occurs in a self-propagating mode in a homogeneous thermal film plane field at heating rates above 20 K/s and at temperatures above initiation temperature T{sub in} ∼ 180 °S. At heating rates lower than 20 K/s the mixing of the In and Fe{sub 2}O{sub 3} layers occurs across the whole In/Fe{sub 2}O{sub 3} interface and the synthesis of the ferromagnetic α-Fe phase starts above the initiation temperature T{sub in} = 180 °S. X-ray diffraction, X-ray photoelectron spectroscopy, Mossbauer spectroscopy, transmission electron microscopy and magnetic measurements were used for phase identification and microstructure observation of the synthesized Fe–In{sub 2}O{sub 3} samples. The reaction products contain (1 1 0) textured α-Fe nanocrystals with a diameter around 100 nm and surrounded by an In{sub 2}O{sub 3} matrix. These results enable new efficient low-temperature methods for synthesizing ferromagnetic nanocomposite films containing ferromagnetic nanoclusters embedded in transparent conducting oxides.

  11. Impact of alternative solid state forms and specific surface area of high-dose, hydrophilic active pharmaceutical ingredients on tabletability.

    Paluch, Krzysztof J; Tajber, Lidia; Corrigan, Owen I; Healy, Anne Marie

    2013-10-01

    In order to investigate the effect of using different solid state forms and specific surface area (TBET) of active pharmaceutical ingredients on tabletability and dissolution performance, the mono- and dihydrated crystalline forms of chlorothiazide sodium and chlorothiazide potassium (CTZK) salts were compared to alternative anhydrous and amorphous forms, as well as to amorphous microparticles of chlorothiazide sodium and potassium which were produced by spray drying and had a large specific surface area. The tablet hardness and tensile strength, porosity, and specific surface area of single-component, convex tablets prepared at different compression pressures were characterized. Results confirmed the complexity of the compressibility mechanisms. In general it may be concluded that factors such as solid-state form (crystalline vs amorphous), type of hydration (presence of interstitial molecules of water, dehydrates), or specific surface area of the material have a direct impact on the tabletability of the powder. It was observed that, for powders of the same solid state form, those with a larger specific surface area compacted well, and better than powders of a lower surface area, even at relatively low compression pressures. Compacts prepared at lower compression pressures from high surface area porous microparticles presented the shortest times to dissolve, when compared with compacts made of equivalent materials, which had to be compressed at higher compression pressures in order to obtain satisfactory compacts. Therefore, materials composed of nanoparticulate microparticles (NPMPs) may be considered as suitable for direct compaction and possibly for inclusion in tablet formulations as bulking agents, APIs, carriers, or binders due to their good compactibility performance. PMID:23961942

  12. All-solid-state high performance asymmetric supercapacitors based on novel MnS nanocrystal and activated carbon materials

    Chen, Teng; Tang, Yongfu; Qiao, Yuqing; Liu, Zhangyu; Guo, Wenfeng; Song, Jianzheng; Mu, Shichun; Yu, Shengxue; Zhao, Yufeng; Gao, Faming

    2016-03-01

    All-solid-state high-performance asymmetric supercapacitors (ASCs) are fabricated using γ-MnS as positive electrode and porous eggplant derived activated carbon (EDAC) as negative electrode with saturated potassium hydroxide agar gel as the solid electrolyte. The laminar wurtzite nanostructure of γ-MnS facilitates the insertion of hydroxyl ions into the interlayer space, and the manganese sulfide nanowire offers electronic transportation channels. The size-uniform porous nanostructure of EDAC provides a continuous electron pathway as well as facilitates short ionic transportation pathways. Due to these special nanostructures of both the MnS and the EDAC, they exhibited a specific capacitance of 573.9 and 396 F g‑1 at 0.5 A g‑1, respectively. The optimized MnS//EDAC asymmetric supercapacitor shows a superior performance with specific capacitance of 110.4 F g‑1 and 89.87% capacitance retention after 5000 cycles, a high energy density of 37.6 Wh kg‑1 at a power density of 181.2 W kg‑1 and remains 24.9 Wh kg‑1 even at 5976 W kg‑1. Impressively, such two assembled all-solid-state cells in series can light up a red LED indicator for 15 minutes after fully charged. These impressive results make these pollution-free materials promising for practical applications in solid aqueous electrolyte-based ASCs.

  13. Synthesis of Nano-sized Barium Titanate Powder by Solid-state Reaction between Barium Carbonate and Titania

    2007-01-01

    Size control of BaTiO3 in solid-state reaction between BaCO3 and TiO2 was demonstrated by varying the size of TiO2 and milling conditions of BaCO3. The smaller TiO2 particles had higher surface area, resulting in faster initial reaction. The mechanically milled BaCO3 particles accelerated the diffusion process and decreased the calcinations temperature. It can be deduced from the results that the size control is possible and nano-sized BaTiO3 particles with about 60 nm can be synthesized by using the conventional solid-state reaction between BaCO3 and TiO2.

  14. Synthesis of nano-BaTiO3 by solid-state reaction at 80 deg. C

    Nano-BaTiO3 powder was synthesized by solid-state reaction at 80 deg. C.The method is high productive and can be easily operated. XRD pattern demonstrates that the powder is pure cubic phase. And TEM photograph of the powder shows that the particles are uniform and spherical with average size of 50nm in diameter. Furthermore we confirmed that chemical reaction is the rate-determining step.

  15. Statistical optimization of thermo-tolerant xylanase activity from Amazon isolated Bacillus circulans on solid-state cultivation.

    Heck, Júlio Xandro; Flôres, Simone Hickmann; Hertz, Plinho Francisco; Ayub, Marco Antônio Záchia

    2006-10-01

    A 2(2) factorial design was performed to find the best conditions of pH and temperature for xylanolytic activity of Bacillus circulans BL53 isolated from the Amazon environment. Solid-state cultivation was carried out on an inexpensive, abundant agro-industrial soybean residue. The central composite design (CCD) used for the analysis of treatment combinations showed that a second-order polynomial regression model was in good agreement with experimental results, with R(2) = 0.9369 (P processes. The crude enzyme extract hydrolyzed rice straw, sugar cane bagasse and soybean fiber and its activity was stimulated by Co(2+), Fe(3+), and beta-mercaptoethanol but inhibited by Mn(2+), Cu(2+), Ca(2+), Zn(2+), Ba(2+), Mg(2+) and by EDTA. PMID:16216495

  16. Aldo-keto synthesis effect on Eu3+fluorescence in YBO3 compared with solid state diffusion

    K.A. Koparkar; N.S. Bajaj; S.K. Omanwar

    2015-01-01

    The red-orange emitting phosphor YBO3:Eu3+was prepared by aldo-keto method and solid state diffusion. Aldo-keto method implied to decrease the processing time and heating temperature. The red-orange emitting phosphor was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as emission and excitation photoluminescence spectra re-corded at room temperature. The result of aldo-keto method showed that the phosphor YBO3:Eu3+could be obtained at 900 °C in less time~60%as compared to solid state diffusion (SSD). The material showed that the strongest emission peak at 595 nm under excitation at 233 nm was only due to forced magnetic dipole 5D0→7F1 transition of Eu3+ions. Significantly, the emission inten-sity of YBO3:Eu3+phosphor prepared by aldo-keto method was relatively higher as compared to that obtained by the solid state diffusion.

  17. Two step solid state synthesis and Synchrotron X-ray characterizations of ceramic Co3TeO6; an improper multiferroic

    Singh, Harishchandra; Sinha, A. K.; S. M. Gupta; Singh, M. N.; Ghosh, H.

    2015-01-01

    A two step solid state reaction route has been presented to synthesize monophasic cobalt tellurate (Co3TeO6, CTO) using Co3O4 and TeO2 as starting reagents. During synthesis, initial ingredient Co3O4 is found better than CoO in circumventing the intermediate Co5TeO8 or CoTeO3 phases. High resolution Synchrotron X-ray Diffraction has been used to probe different phases present in synthesized CTO and to achieve its single phase. Further, XANES studies near Co K and Te L-edge reveal mixed oxidat...

  18. Solid-state synthesis of alpha-Fe and iron carbide nanoparticles by thermal treatment of amorphous Fe2O3

    Schneeweiss, Oldřich; Zbořil, R.; David, Bohumil; Heřmánek, M.; Mašláň, M.

    New York: Springer, 2009 - (Kuzmann, E.; Lazar, K.), s. 167-173 ISBN 978-3-642-01369-0. [International Symposium on the Industrial Applications of the Mossbauer Effect (ISIAME 2008) /7./. Budapest (HU), 17.08.2008-22.08.2008] R&D Projects: GA ČR GA106/08/1440; GA MŠk 1M0512 Institutional research plan: CEZ:AV0Z20410507 Keywords : Iron oxides * Solid-state synthesis * Nanocrystalline powder Subject RIV: BM - Solid Matter Physics ; Magnetism

  19. KfK Institute of Nuclear Solid State Physics. Progress report on research and development activities in 1990

    The INFP is primarily occupied with basic research work in the field of solid state physics and materials science, with preference being given to subjects and problems of interest from the point of view of potential applications. This is particularly true for research work devoted to the high-temperature superconductors, which currently are the area of main effort of the Institute, but also for work performed in the fields of interface and microstructure research, polymer physics, or studies on amorphous and glassy materials. In 1990, about 70% of the activities were superconductivity research. Basic research investigated the lattice dynamics and electronic structure of HT superconductors by means of inelastic neutron scattering, or electron energy loss spectroscopy and tunnel spectroscopy. Application-oriented work concentrated on the development of HTSC-films required for equipment in microwave engineering, microelectronics, and sensor engineering. (orig./MM)

  20. Solid state reaction synthesis of Ba{sub 0}.75Sr{sub 0}.25AlSi{sub 2}O{sub 8} - Al{sub 2}O{sub 3} ceramic composites from mechanically activated precursor mixtures

    Ramos-Ramirez, M. V.; Lopez-Cuevas, J.; Rodriguez-Galicia, J. L.; Rendon-Angeles, J. C.

    2014-10-01

    Ceramic composites with Ba{sub 0}.75Sr{sub 0}.25AlSi{sub 2}O{sub 8} (SBAS)/Al{sub 2}O{sub 3} mass ratios of: 1) 90/10, 2) 70/30, and 3) 50/50, were in situ synthesized at 900-1500 degree centigrade/5 h from mixtures of fly ash, BaCO{sub 3}, SrCO{sub 3} and Al{sub 2}O{sub 3}. The green mixtures were mechanically activated for 0, 4 and 8 h in an attrition mill. As a result, the solid state reactions were faster and occurred at lower temperatures. Only the SBAS and Al{sub 2}O{sub 3} phases were obtained at 1300-1500 degree centigrade, with the SBAS present in composition 1 achieving full conversion from its hexagonal (Hexacelsian) into its monoclinic (Celsian) form, with or without milling. The higher nominal SBAS content of composition 1 facilitated in it the mentioned conversion, in comparison with the other two studied compositions, which required to be mechanically activated for times that increased with increasing Al{sub 2}O{sub 3} content, in order to attain in them similarly high Hexacelsian to Celsian conversions. The mechanical properties of the synthesized materials increased with increasing milling time, sintering temperature and Al{sub 2}O{sub 3} content. Thus, the best mechanical properties were obtained for composition 3 milled for 8 h and sintered at 1500 degree centigrade. (Author)

  1. Solid state synthesis and characterization of sodium zirconium phosphate (NZP): A review of issues and characterization facilities

    Materials synthesis and characterization with a view to tailoring them for specific applications has the potential to assuage the enormous challenges besetting our socio-economic lives and resolve our energy crises. This is possible through the identification and development of materials that have potential to complement our dependence on fossil fuels and that are most appropriate in alleviating the recurrent and persistent fuel crises in the energy sector. At the moment there is an avalanche of research activities taking place in the various alternative energy options to develop renewable sources of energy with enormous implications for our revenue base. The study of NASICON materials for potential energy applications in diverse fields such as fuel cells for transportation, rechargeable lithium batteries, biomaterials, nuclear waste demobilization and environmental concerns, among others has been actively pursued by different groups of researchers. However, the synthesi s and characterization of these materials is challenging and presents its peculiar problems in terms of material and human resources and the irreconcilable atmosphere for research with the existing institutional policy framework within which researchers have to operate in general. The paper reviews the relevant issues and instrumental readiness of some surveyed institutions in carrying out research within the Nigerian context based on the ongoing research on Sodium Zirconium Phosphate (NZP), a member of NASICON family and proffers solutions to them.

  2. Solid state magnetism

    Crangle, John

    1991-01-01

    Solid state magnetism is important and attempts to understand magnetic properties have led to an increasingly deep insight into the fundamental make up of solids. Both experimental and theoretical research into magnetism continue to be very active, yet there is still much ground to cover before there can be a full understanding. There is a strong interplay between the developments of materials science and of magnetism. Hundreds of new materials have been dis­ covered, often with previously unobserved and puzzling magnetic prop­ erties. A large and growing technology exists that is based on the magnetic properties of materials. Very many devices used in everyday life involve magnetism and new applications are being invented all the time. Under­ standing the fundamental background to the applications is vital to using and developing them. The aim of this book is to provide a simple, up-to-date introduction to the study of solid state magnetism, both intrinsic and technical. It is designed to meet the needs a...

  3. Rapid Synthesis of Lead Oxide Nanorods by One-step Solid-state Chemical Reaction at Room Temperature

    CAO, Ya-Li(曹亚丽); JIA, Dian-Zeng(贾殿赠); LIU, Lang(刘浪); LUO, Jian-Min(骆建敏)

    2004-01-01

    A simple and facile method was reported to synthesize lead oxide nanorods. Nanorods of lead oxide were obtained directly from grinding solid metal salt and sodium hydroxide in agate mortar with the assistance of a suitable nonionic surfactant in only one step, which is different from the result of hydroxide in solution. The product has been characterized by XRD, TEM and SEM. The formation mechanism of rod-like morphology is discussed and the surfactant plays an important soft-template role in modifying the interface of solid-state reaction and according process of rod-formation.

  4. Solid state reaction synthesis and luminescence properties of Dy3+-doped Gd2Mo3O9 phosphor

    Gd2Mo3O9 phosphors with various Dy3+ concentrations were synthesized by a traditional solid-state reaction using Na2CO3 as a flux. The influence of reaction temperature and Dy3+-doping concentration on the crystal structure of the phosphors was examined by XRD (X-ray diffraction). The effect of Dy3+-doping concentration on the emissions of Mo–O bond and Dy3+ was experimentally investigated. The energy transfers between host and Dy3+ ions, and between Dy3+ ions were analyzed based on both the Van Uitert and I-H models. The chromatic properties of the phosphors were also discussed.

  5. Facile synthesis of PbTiO3 truncated octahedra via solid-state reaction and their application in low-temperature CO oxidation by loading Pt nanoparticles

    Yin, Simin

    2014-01-01

    Perovskite PbTiO3 (PTO) nanocrystals with a truncated octahedral morphology have been prepared by a facile solid-state reaction. Pt nanoparticles preferentially nucleated on the {111} facet of PTO nanocrystals exhibit a remarkable low-temperature catalytic activity towards CO oxidation from a temperature as low as 30 °C and achieve 100% conversion at ∼50 °C. © 2014 the Partner Organisations.

  6. A Novel Activated-Charcoal-Doped Multiwalled Carbon Nanotube Hybrid for Quasi-Solid-State Dye-Sensitized Solar Cell Outperforming Pt Electrode.

    Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Choi, Yun Seon; Jeong, Sung Hoon

    2016-03-23

    Highly conductive mesoporous carbon structures based on multiwalled carbon nanotubes (MWCNTs) and activated charcoal (AC) were synthesized by an enzymatic dispersion method. The synthesized carbon configuration consists of synchronized structures of highly conductive MWCNT and porous activated charcoal morphology. The proposed carbon structure was used as counter electrode (CE) for quasi-solid-state dye-sensitized solar cells (DSSCs). The AC-doped MWCNT hybrid showed much enhanced electrocatalytic activity (ECA) toward polymer gel electrolyte and revealed a charge transfer resistance (RCT) of 0.60 Ω, demonstrating a fast electron transport mechanism. The exceptional electrocatalytic activity and high conductivity of the AC-doped MWCNT hybrid CE are associated with its synchronized features of high surface area and electronic conductivity, which produces higher interfacial reaction with the quasi-solid electrolyte. Morphological studies confirm the forms of amorphous and conductive 3D carbon structure with high density of CNT colloid. The excessive oxygen surface groups and defect-rich structure can entrap an excessive volume of quasi-solid electrolyte and locate multiple sites for iodide/triiodide catalytic reaction. The resultant D719 DSSC composed of this novel hybrid CE fabricated with polymer gel electrolyte demonstrated an efficiency of 10.05% with a high fill factor (83%), outperforming the Pt electrode. Such facile synthesis of CE together with low cost and sustainability supports the proposed DSSCs' structure to stand out as an efficient next-generation photovoltaic device. PMID:26911208

  7. Solid state video cameras

    Cristol, Y

    2013-01-01

    Solid State Video Cameras reviews the state of the art in the field of solid-state television cameras as compiled from patent literature. Organized into 10 chapters, the book begins with the basic array types of solid-state imagers and appropriate read-out circuits and methods. Documents relating to improvement of picture quality, such as spurious signal suppression, uniformity correction, or resolution enhancement, are also cited. The last part considerssolid-state color cameras.

  8. Solid-state synthesis of Ti2Nb10O29/reduced graphene oxide composites with enhanced lithium storage capability

    Wang, Wan Lin; Oh, Byeong-Yun; Park, Ju-Young; Ki, Hangil; Jang, Jaewon; Lee, Gab-Yong; Gu, Hal-Bon; Ham, Moon-Ho

    2015-12-01

    Owing to their multiple redox couples, titanium-niobium-based oxides are still considered promising candidates for use as anodes for safe, rechargeable lithium ion batteries with high energy and power densities. Titanium-niobium-based oxide electrodes have, however, exhibited relatively poor cycling performance as a result of pulverization. In this study, we report on a simple two-step solid-state reaction route for producing hybrid composites of Ti2Nb10O29 (TNO) anchored on reduced graphene oxide (RGO), and the electrochemical performance of the resulting TNO/RGO composites. Solid-state reactions enable both the formation of TNO and the uniform distribution of RGO in the TNO/RGO composites. The TNO/RGO composites exhibited discharge and charge capacities of 261 and 256 mAh g-1, respectively, with much better cycling performance (182 mAh g-1 after the 50th cycles) and rate capability (165 mAh g-1 at a current density of 500 mA g-1) compared to the pure TNO.

  9. Solid state physics

    Burns, Gerald

    2013-01-01

    Solid State Physics, International Edition covers the fundamentals and the advanced concepts of solid state physics. The book is comprised of 18 chapters that tackle a specific aspect of solid state physics. Chapters 1 to 3 discuss the symmetry aspects of crystalline solids, while Chapter 4 covers the application of X-rays in solid state science. Chapter 5 deals with the anisotropic character of crystals. Chapters 6 to 8 talk about the five common types of bonding in solids, while Chapters 9 and 10 cover the free electron theory and band theory. Chapters 11 and 12 discuss the effects of moveme

  10. Micro-Fabricated Solid-State Radiation Detectors for Active Personal Dosimetry

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.; Chen, Liang-Yu

    2007-01-01

    Active radiation dosimetry is important to human health and equipment functionality for space applications outside the protective environment of a space station or vehicle. This is especially true for long duration missions to the moon, where the lack of a magnetic field offers no protection from space radiation to those on extravehicular activities. In order to improve functionality, durability and reliability of radiation dosimeters for future NASA lunar missions, single crystal silicon carbide devices and scintillating fiber detectors are currently being investigated for applications in advanced extravehicular systems. For many years, NASA Glenn Research Center has led significant efforts in silicon carbide semiconductor technology research and instrumentation research for sensor applications under extreme conditions. This report summarizes the technical progress and accomplishments toward characterization of radiation-sensing components for the recommendation of their fitness for advanced dosimetry development.

  11. Solid-state radiation detectors for active personal dosimetry and radiations source tracking

    We report on the design of the readout electronics using PIN diode radiation detector of 5 mm thickness for nuclear safety and active personal dosimetry. Our effort consisted in designing and fabricating the electronics to reflect the needs of gamma radiations dosimetry and hybrids PIN diode arrays for charged particle detectors. We report results obtained during testing and characterizing the new devices in gamma fields, operating at room temperature. There were determined the energy spectrum resolution, radiation hardness and readout rate. Also, data recording methods and parallel acquisition problems from a transducer matrix are presented. (authors)

  12. Synthesis of monoclinic Celsian from coal fly ash by using a one-step solid-state reaction

    Long Gonzalez, D.; López Cuevas, J.; Gutierrez Chavarria, C.A.; Pena, P.; Baudin, C.; Turrillas Maisterra, Javier Miguel

    2010-01-01

    Monoclinic (Celsian) and hexagonal (Hexacelsian) Ba1−xSrxAl2Si2O8 solid solutions, where x = 0, 0.25, 0.375, 0.5, 0.75 or 1, were synthesized by using Coal Fly Ash (CFA) as main raw material, employing a simple one-step solid-state reaction process involving thermal treatment for 5 h at 850–1300 °C. Fully monoclinic Celsian was obtained at 1200 °C/5 h, for SrO contents of 0.25 ≤ x ≤ 0.75. However, an optimum SrO level of 0.25 ≤ x ≤ 0.375 was recommended for the stabilization of Celsian. These...

  13. Colloidal Sb2S3 Nanocrystals: Synthesis, Characterization and Fabrication of Solid-State Semiconductor Sensitized Solar Cell

    Abulikemu, Mutalifu

    2015-12-26

    Inorganic nanocrystals composed of earth-abundant and non-toxic elements are crucial to fabricated sustainable photovoltaic devices in large scale. In this study, various-shaped and different phases of antimony sulfide nanocrystals, which is composed of non-scarce and non-toxic elements, are synthesized using hot-injection colloidal method. The effect of various synthetic parameters on the final morphology is explored. Also, foreign ion (Chlorine) effects on the morphology of Sb2S3 nanocrystals have been observed. Structural, optical and morphological properties of the nanocrystals were investigated, and Sb2S3 nanocrystal-based solid-state semiconductor-sensitized solar cells were fabricated using as-prepared nanocrystals. We achieved promising power conversion efficiencies of 1.48%.

  14. Studies on solid state synthesis and the oxygenation property of cobalt(II) Schiff base (vanilline polyamine)complexes

    XIAO Furong; CHEN Lu; WANG Jide; WU Ronglan; YUE Fan; LI Jing

    2007-01-01

    Three new cobalt complexes were synthesized by solid-state reaction at room temperature and the resultant Co complexes reacted with two equivalent oxygen molecules at room temperature to produce the oxygenated complexes 2H2O (L3=N, N'-bis(4-hydroxyl-3-methoxy-benzyltetraethylenepentamine).The oxygenated complexes were characterized by elemental analysis,IR (Infrared),1H-NMR (Nuclear Magnetic Resonance),and UV-Vis (Ultraviolet Visual) spectrometry,and TG/DTA (Thermogravimetry/Differential Thermal Analysis) analysis,and molar conductance.The coordinated oxygen contents in the oxygenated complexes were also determined by weight method.It was supposed that only one O2 molecule coordinated to the Co ion forming a superoxo type oxygenated complex.

  15. Solid-state synthesis and electrochemical properties of SmVO4 cathode materials for low temperature SOFCs

    SUN Xueli; LI Song; SUN Juncai

    2006-01-01

    A new cathode material fabricated by solid state reaction method was reported. The SmVO4 powder was obtained by firing the mixture of Sm2O3 and V2O5 powders in the temperature range of 700-1200 ℃. Its structure was identified by X-ray diffraction method and the electrochemical properties of SmVO4 as cathodes for solid oxide fuel cells (SOFCs) were investigated in single unit cell at the temperature ranged from 450-550 ℃. The results of the single fuel cell unit show that the maximum current densities are 641, 797, 688 mA·cm-2 and the maximum power output are 165, 268, 303 mW·cm-2 and the open circuit voltage are 1.04,0.96,0.92Vat 450, 500 and 550 ℃, respectively.

  16. Studies on Possible Activation of Microbial Inulinase Production Using Gamma Radiation Under Solid State Fermentation

    optimization of different parameters affecting productivity of inulinase/invertase enzyme by Penicillium chrysogenum was studied. Optimized media used was Wheat bran: Jerusalem artichoke (4:1) 66% moisture content acidified mineral solution (ph 4.9). spore suspension 1.8 x 107 spores/ml irradiated with 1.00 kGy of gamma radiation. distilled water ph 6 (extracting solvent), corn steep liquor 0.6%, Corn oil, SDS and CaCl2 with incubation temperature 35°C for 72 hr. Immobilization of a partially purified inulinase enzyme from a local gamma irradiated strain of Penicillium chrysogenum on cheap immobilization supports was carried out. Highest inulinase immobilized activity was maintained on Ca- alginate beads. The immobilized enzyme showed a marked enhancement with temperature, ph optima, and thermostability, thus suggesting a promising industrial production of fructose syrup using the immobilized enzyme.

  17. Needle Type Solid State Detectors for In-Vivo Measurement of Tracer Activity

    A set of miniature detector probes for in-vivo-measurement of beta and gamma tracer activity is described. The probes use a lithium-compensated p-i-n silicon detector as sensing element. The standard 'needle probe' contains a cylindrical detector 0.9 mm in diameter and 3 mm long, enclosed in a stainless steel tube 1.1 mm in outer diameter and with walls 0. 05 mm thick. For particular applications several modified types have been developed: probes with larger sensing elements, probes with extra thin walls for low-energy beta detection, probes with two or three sensing elements in the same needle and probes containing a movable sensing element. This report describes the construction and the properties of the different needle probes

  18. Needle Type Solid State Detectors for In-Vivo Measurement of Tracer Activity

    Lauber, A. [AB Atomenergi, Nykoeping (Sweden); Wolgast, W. [Univ. of Uppsala (Sweden). Inst. of Physiology and Medical Biophysics

    1970-07-15

    A set of miniature detector probes for in-vivo-measurement of beta and gamma tracer activity is described. The probes use a lithium-compensated p-i-n silicon detector as sensing element. The standard 'needle probe' contains a cylindrical detector 0.9 mm in diameter and 3 mm long, enclosed in a stainless steel tube 1.1 mm in outer diameter and with walls 0. 05 mm thick. For particular applications several modified types have been developed: probes with larger sensing elements, probes with extra thin walls for low-energy beta detection, probes with two or three sensing elements in the same needle and probes containing a movable sensing element. This report describes the construction and the properties of the different needle probes.

  19. Towards a lattice-matching solid-state battery: synthesis of a new class of lithium-ion conductors with the spinel structure.

    Rosciano, Fabio; Pescarmona, Paolo P; Houthoofd, Kristof; Persoons, Andre; Bottke, Patrick; Wilkening, Martin

    2013-04-28

    Lithium ion batteries have conquered most of the portable electronics market and are now on the verge of deployment in large scale applications. To be competitive in the automotive and stationary sectors, however, they must be improved in the fields of safety and energy density (W h L(-1)). Solid-state batteries with a ceramic electrolyte offer the necessary advantages to significantly improve the current state-of-the-art technology. The major limit towards realizing a practical solid-state lithium-ion battery lies in the lack of viable ceramic ionic conductors. Only a few candidate materials are available, each carrying a difficult balance between advantages and drawbacks. Here we introduce a new class of possible solid-state lithium-ion conductors with the spinel structure. Such compounds could be coupled with spinel-type electrode materials to obtain a "lattice matching" solid device where low interfacial resistance could be achieved. Powders were prepared by wet chemistry, their structure was studied by means of diffraction techniques and magic angle spinning NMR, and Li(+) self-diffusion was estimated by static NMR line shape measurements. Profound differences in the Li(+) diffusion properties were observed depending on the composition, lithium content and cationic distribution. Local Li(+) hopping in the spinel materials is accompanied by a low activation energy of circa 0.35 eV being comparable with that of, e.g., LLZO-type garnets, which represent the current benchmark in this field. We propose these novel materials as a building block for a lattice-matching all-spinel solid-state battery with low interfacial resistance. PMID:23503337

  20. Influence of solid state fermentation by Trichoderma spp. on solubility, phenolic content, antioxidant, and antimicrobial activities of commercial turmeric.

    Mohamed, Saleh A; Saleh, Rashad M; Kabli, Saleh A; Al-Garni, Saleh M

    2016-05-01

    The influence of solid state fermentation (SSF) by Trichoderma spp. on the solubility, total phenolic content, antioxidant, and antibacterial activities of turmeric was determined and compared with unfermented turmeric. The solubility of turmeric was monitored by increase in its phenolic content. The total phenolic content of turmeric extracted by 80% methanol and water after SSF by six species of Trichoderma spp. increased significantly from 2.5 to 11.3-23.3 and from 0.5 to 13.5-20.4 GAE/g DW, respectively. The antioxidant activities of fermented turmeric were enhanced using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS), and ferric ion-reducing antioxidant power (FRAP) assays. The antibacterial activity of fermented turmeric against human-pathogenic bacteria Escherichia coli, Streptococcus agalactiae, Staphylococcus aureus, Entreococcus faecalis, Methicillin-Resistant S. aureus, Klebsiella pneumonia, and Pseudomonas aeruginosae showed a broad spectrum inhibitory effect. In conclusion, the results indicated the potentials of using fermented turmeric as natural antioxidant and antimicrobial material for food applications. PMID:27023794

  1. Solid state synthesis, characterization and optical properties of Tb doped SrSnO{sub 3} phosphor

    Kotan, Z. [Ege University, Institute of Nuclear Sciences, 35100 Bornova-İzmir (Turkey); Ayvacikli, M.; Karabulut, Y. [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, 45010 Muradiye-Manisa (Turkey); Garcia-Guinea, J.; Tormo, L. [Museo Nacional Ciencias Naturales, Jose Gutierrez Abascal 2, Madrid 28006 (Spain); Canimoglu, A. [Niğde University, Faculty of Arts and Sciences, Department of Physics, Niğde (Turkey); Karali, T. [Ege University, Institute of Nuclear Sciences, 35100 Bornova-İzmir (Turkey); Can, N., E-mail: cannurdogan@yahoo.com [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, 45010 Muradiye-Manisa (Turkey)

    2013-12-25

    Highlights: •A new stannate phosphor, SrSnO{sub 3}:Tb{sup 3+} was synthesized by solid state reaction method. •The role of Tb{sup 3+} doped into SrSnO{sub 3} was discussed. •A structural phase transition in SrSnO{sub 3}:Tb{sup 3+} at ∼270 K was suggested. -- Abstract: In the present study, the structural and optical properties of SrSnO{sub 3} doped with Tb ions are reported. Novel SrSnO{sub 3}:Tb{sup 3+} phosphors were conventionally synthesized using a solid state reaction process under a mildly reduced atmosphere (5%H{sub 2} and 95%N{sub 2}). The crystal structures, morphologies and optical properties of the resultant materials have been characterised by experimental techniques such as X-ray Diffraction (XRD), Raman spectroscopy (RS), Photoluminescence (PL), Radioluminescence (RL) and Cathodoluminescence coupled to an ESEM (ESEM-CL). The new phosphor material has good crystallization without any impurity phases, which matches with the standard JCPDS files (No. 22-1442) from XRD analysis. The PL, RL and CL measurements taken at room temperature showed that the transitions of {sup 5}D{sub 4} to {sup 7}F{sub J} (j = 6, 5, 4, 3) corresponding to the typical 4f → 4f dipole forbidden intra-configurational transitions of Tb{sup 3+} are largely independent of the host material. The green emissions of the {sup 5}D{sub 4} → {sup 7}F{sub 5} magnetic dipole transition at ∼540 nm are predominant for three types of luminescence. PL emission spectra recorded in the temperature range from 10 K to 300 K were influenced by temperature. We report anomalies in the PL spectra of SrSnO{sub 3}:Tb{sup 3+} compatible with a structural phase transition at 260 K while simultaneously exciting and cooling the sample. This work clearly confirms the existence of a phase transition discovered by Singh et al. in SrSnO{sub 3} at 270 K.

  2. Bottom-Up Fabrication of Activated Carbon Fiber for All-Solid-State Supercapacitor with Excellent Electrochemical Performance.

    Ma, Wujun; Chen, Shaohua; Yang, Shengyuan; Chen, Wenping; Weng, Wei; Zhu, Meifang

    2016-06-15

    Activated carbon (AC) is the most extensively used electrode material for commercial electric double layer capacitors (EDLC) given its high specific surface area (SSA) and moderate cost. However, AC is primarily used in the forms of powders, which remains a big challenge in developing AC powders into continuous fibers. If AC powders can be processed into fiber, then they may be scaled up for practical applications to supercapacitors (SCs) and satisfy the rapid development of flexible electronics. Herein, we report a bottom-up method to fabricate AC fiber employing graphene oxide (GO) as both dispersant and binder. After chemical reduction, the fiber has high electrical conductivity (185 S m(-1)), high specific surface area (1476.5 m(2) g(-1)), and good mechanical flexibility. An all solid-state flexible SC was constructed using the prepared fiber as electrode, which is free of binder, conducting additive, and additional current collector. The fiber-shaped SC shows high capacitance (27.6 F cm(-3) or 43.8 F g(-1), normalized to the two-electrode volume), superior cyclability (90.4% retention after 10 000 cycles), and good bendability (96.8% retention after bending 1000 times). PMID:27239680

  3. Theoretical solid state physics

    Haug, Albert

    2013-01-01

    Theoretical Solid State Physics, Volume 1 focuses on the study of solid state physics. The volume first takes a look at the basic concepts and structures of solid state physics, including potential energies of solids, concept and classification of solids, and crystal structure. The book then explains single-electron approximation wherein the methods for calculating energy bands; electron in the field of crystal atoms; laws of motion of the electrons in solids; and electron statistics are discussed. The text describes general forms of solutions and relationships, including collective electron i

  4. The solid state maser

    Orton, J W; Walling, J C; Ter Haar, D

    1970-01-01

    The Solid State Maser presents readings related to solid state maser amplifier from the first tentative theoretical proposals that appeared in the early 1950s to the successful realization of practical devices and their application to satellite communications and radio astronomy almost exactly 10 years later. The book discusses a historical account of the early developments (including that of the ammonia maser) of solid state maser; the properties of paramagnetic ions in crystals; the development of practical low noise amplifiers; and the characteristics of maser devices designed for communica

  5. Synthesis and characterization of M3V2O8 (M = Ca, Sr and Ba) by a solid-state metathesis approach

    Purnendu Parhi; V Manivannan; Sandeep Kohli; Patrick Mccurdy

    2008-11-01

    A solid-state metathesis approach initiated by microwave energy has been successfully applied for the synthesis of orthovanadates, M3V2O8 (M = Ca, Sr, and Ba). The structural, vibrational, thermal, optical and chemical properties of synthesized powders are determined by powder X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, magnetic property measurements and diffused reflectance spectra in the UV–VIS range. The direct bandgap of the synthesized materials was found to be 3.55 ± 0.2 eV, 3.75 ± 0.2 eV and 3.57 ± 0.2 eV for Ca3V2O8, Sr3V2O8 and Ba3V2O8, respectively.

  6. Solid-state synthesis and characterization of LiCoO2 and LiNiCo1–O2 solid solutions

    P Periasamy; B Ramesh Babu; R Thirunakaran; N Kalaiselvi; T Prem Kumar; N G Renganathan; M Raghavan; N Muniyandi

    2000-10-01

    Solid solutions of compositions LiNiCo1–O2 ( = 0.0, 0.1 and 0.2) were prepared by solid-state fusion synthesis from carbonate precursors. Material characterization was carried out using XRD. Formation mechanisms of the products are discussed in the light of TG/DTA results. Nickel-containing compositions gave higher discharge capacities and smaller hystereses in their charge–discharge profiles which make them more attractive than pristine LiCoO2 as cathode materials in high-energy lithium cells. The lower loss in capacity per cycle for cells with unsubstituted LiCoO2 , as determined from cycling studies up to 25 cycles, makes it more suitable than the substituted ones for long cycle-life cells with low capacity fade.

  7. Synthesis, characterization and thermal behaviour of solid-state compounds of benzoates with some bivalent transition metal ions

    Adriano B. Siqueira

    2007-04-01

    Full Text Available Solid-state MBz compounds, where M stands for bivalent Mn, Fe, Co, Ni, Cu and Zn and Bz is benzoate, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA, differential scanning calorimetry (DSC, infrared spectroscopy and complexometry were used to characterize and to study the thermal behaviour of these compounds. The procedure used in the preparation of the compounds via reaction of basic carbonates with benzoic acid is not efficient in eliminating excess acid. However the TG-DTA curves permitted to verify that the binary compounds can be obtained by thermosynthesis, because the benzoic acid can be eliminated before the thermal decomposition of these compounds. The results led to information about the composition, dehydration, thermal stability, thermal decomposition and structure of the isolated compounds. On heating, these compounds decompose in two (Mn, Co, Ni, Zn or three (Fe, Cu steps with formation of the respective oxide (Mn3O4, Fe2O3, Co3O4, NiO, CuO and ZnO as final residue. The theoretical and experimental spectroscopic studies suggest a covalent bidentate bond between ligand and metallic center.

  8. Salt-assisted Low Temperature Solid State Synthesis of High Surface Area CoFe2O4 Nanoparticles

    Runhua Qin; Fengsheng Li; Wei Jiang; Li Liu

    2009-01-01

    A novel salt-assisted low temperature solid state method using CoCl2·6H2O, FeCl3·6H2O and NaOH as pre-cursor and using NaCl as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. The effects of the molar ratio of added salt and calcination temperature on the characteristics of the products were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and Brunauer, Emmett and Teller (BET) surface area analysis. Results showed that the introduction of leachable inert inorganic salt as a hard agglomeration inhibitor in the mixture precursorled to the formation of high dispersive CoFe2O4 nanoparticles; and the increase in specific surface area from 28.28 to 73.97 m2/g, and the saturation magnetization is 84.6 emu/g.

  9. Solid-state synthesis of monocrystalline iron oxide nanoparticle based ferrofluid suitable for magnetic resonance imaging contrast application

    A new γ-Fe2O3 MION ferrofluid has been developed with a salt-assisted solid-state reaction. Characterizations show that the ferrofluid is composed of maghemite nanoparticles with a mean diameter of 2.7 nm. Though the nanoparticles are ultrafine, they are well crystallized, with a saturation magnetization value of 34.7 emu g-1, making them suitable for MRI applications. In spite of the absence of any surfactant, the ferrofluid can be stable for more than 6 months. An in vitro cytotoxicity test revealed good biocompatibility of the maghemite nanoparticles, suggesting that they may be further explored for biomedical applications. NMR measurements revealed significantly reduced water proton relaxation times T1 and T2. The MR images of the nanoparticles in aqueous dispersion were investigated using a 3 T clinical MR imager. These preliminary experiments have demonstrated the potential of the as-synthesized ultrafine, cap-free maghemite MIONs in functional molecular imaging for biomedical research and clinical diagnosis

  10. Solid-state synthesis of monocrystalline iron oxide nanoparticle based ferrofluid suitable for magnetic resonance imaging contrast application

    Lu Jun [Department of Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Yang Shihe [Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Ng, K M [Department of Chemical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Su, C-H [Department of Chemistry and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan (China); Yeh, C-S [Department of Chemistry and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan (China); Wu, Y-N [Institute of Oral medicine and Center for Micro/Nano Science and Technology, National Cheng Kung University College of Medicine, Tainan 701, Taiwan (China); Shieh, D-B [Institute of Oral medicine and Center for Micro/Nano Science and Technology, National Cheng Kung University College of Medicine, Tainan 701, Taiwan (China)

    2006-12-14

    A new {gamma}-Fe{sub 2}O{sub 3} MION ferrofluid has been developed with a salt-assisted solid-state reaction. Characterizations show that the ferrofluid is composed of maghemite nanoparticles with a mean diameter of 2.7 nm. Though the nanoparticles are ultrafine, they are well crystallized, with a saturation magnetization value of 34.7 emu g{sup -1}, making them suitable for MRI applications. In spite of the absence of any surfactant, the ferrofluid can be stable for more than 6 months. An in vitro cytotoxicity test revealed good biocompatibility of the maghemite nanoparticles, suggesting that they may be further explored for biomedical applications. NMR measurements revealed significantly reduced water proton relaxation times T{sub 1} and T{sub 2}. The MR images of the nanoparticles in aqueous dispersion were investigated using a 3 T clinical MR imager. These preliminary experiments have demonstrated the potential of the as-synthesized ultrafine, cap-free maghemite MIONs in functional molecular imaging for biomedical research and clinical diagnosis.

  11. Welding in solid state

    Iordachescu, Mihaela; Scutelnicu, Elena; Iordachescu, Danut; Ocaña Moreno, Jose Luis

    2008-01-01

    The importance of the Solid State Processes (SSP) has increased in the last decade due to the industry demands of improved properties of joined/surfaced materials, combined with cost reduction and energy saving. New and/or micro-scale solid state processed materials are used by aerospace, automotive and electrotechnics industry. Nowadays, classic SSP are mainly applied to light materials, but progresses were also reported in steels. In this field, the tools design, the technology and practica...

  12. Synthesis, characterization, and solid-state NMR investigation of organically modified bentonites and their composites with LDPE.

    Borsacchi, Silvia; Sudhakaran, Umayal; Geppi, Marco; Ricci, Lucia; Liuzzo, Vincenzo; Ruggeri, Giacomo

    2013-07-23

    Polymer/clay nanocomposites show remarkably improved properties (mechanical properties, as well as decreased gas permeability and flammability, etc.) with respect to their microscale counterparts and pristine polymers. Due to the substantially apolar character of most of the organic polymers, natural occurring hydrophilic clays are modified into organophilic clays with consequent increase of the polymer/clay compatibility. Different strategies have been developed for the preparation of nanocomposites with improved properties, especially aimed at achieving the best dispersion of clay platelets in the polymer matrix. In this paper we present the preparation and characterization of polymer/clay nanocomposites composed of low-density polyethylene (LDPE) and natural clay, montmorillonite-containing bentonite. Two different forms of the clay have been considered: the first, a commercial organophilic bentonite (Nanofil 15), obtained by exchanging the natural cations with dimethyldioctadecylammonium (2C18) cations, and the second, obtained by performing a grafting reaction of an alkoxysilane containing a polymerizable group, 3-(trimethoxysilyl)propyl methacrylate (TSPM), onto Nanofil 15. Both the clays and LDPE/clay nanocomposites were characterized by thermal, FT-IR, and X-ray diffraction techniques. The samples were also investigated by means of (29)Si, (13)C, and (1)H solid-state NMR, obtaining information on the structural properties of the modified clays. Moreover, by exploiting the effect of bentonite paramagnetic (Fe(3+)) ions on proton spin-lattice relaxation times (T1's), useful information about the extent of the polymer-clay dispersion and their interfacial interactions could be obtained. PMID:23786424

  13. Synthesis, characterization and quantitative analysis of porous metal microstructures: Application to microporous copper produced by solid state foaming

    Mark A. Atwater

    2016-05-01

    Full Text Available Porous metals can be created through a wide variety of processing techniques, and the pore morphology resulting from these processes is equally diverse. The structural and functional properties of metal foams are directly dependent on the size, shape, interconnectedness and volume fraction of pores, so accurately quantifying the pore characteristics is of great importance. Methods for analyzing porous materials are presented here and applied to a copper-based metallic foam generated through solid state foaming via oxide reduction and expansion. This process results in large voids (10s of microns between sintered particles and small pores (10 microns to less than 50 nm within particles. Optical and electron microscopy were used to image the porosity over this wide range, and the pore characteristics were quantified using image segmentation and statistical analysis. Two-dimensional pore analysis was performed using the Chan-Vese method, and two-point correlation and lineal path functions were used to assess three-dimensional reconstructions from FIB tomography. Two-dimensional analysis reveals distinct size and morphological differences in porosity between particles and within them. Three-dimensional analysis adds further information on the high level interconnectedness of the porosity and irregular shape it takes, forming tortuous pathways rather than spherical cells. Mechanical polishing and optical microscopy allow large areas to be created and analyzed quickly, but methods such as focused ion beam (FIB sectioning can provide additional insight about microstructural features. In particular, after FIB milling is used to create a flat surface, that surface can be analyzed for structural and compositional information.

  14. Facile template-free synthesis of vertically aligned polypyrrole nanosheets on nickel foams for flexible all-solid-state asymmetric supercapacitors

    Yang, Xiangwen; Lin, Zhixing; Zheng, Jingxu; Huang, Yingjuan; Chen, Bin; Mai, Yiyong; Feng, Xinliang

    2016-04-01

    This paper reports a novel and remarkably facile approach towards vertically aligned nanosheets on three-dimensional (3D) Ni foams. Conducting polypyrrole (PPy) sheets were grown on Ni foam through the volatilization of the environmentally friendly solvent from an ethanol-water solution of pyrrole (Py), followed by the polymerization of the coated Py in ammonium persulfate (APS) solution. The PPy-decorated Ni foams and commercial activated carbon (AC) modified Ni foams were employed as the two electrodes for the assembly of flexible all-solid-state asymmetric supercapacitors. The sheet-like structure of PPy and the macroporous feature of the Ni foam, which render large electrode-electrolyte interfaces, resulted in good capacitive performance of the supercapacitors. Moreover, a high energy density of ca. 14 Wh kg-1 and a high power density of 6.2 kW kg-1 were achieved for the all-solid-state asymmetric supercapacitors due to the wide cell voltage window.This paper reports a novel and remarkably facile approach towards vertically aligned nanosheets on three-dimensional (3D) Ni foams. Conducting polypyrrole (PPy) sheets were grown on Ni foam through the volatilization of the environmentally friendly solvent from an ethanol-water solution of pyrrole (Py), followed by the polymerization of the coated Py in ammonium persulfate (APS) solution. The PPy-decorated Ni foams and commercial activated carbon (AC) modified Ni foams were employed as the two electrodes for the assembly of flexible all-solid-state asymmetric supercapacitors. The sheet-like structure of PPy and the macroporous feature of the Ni foam, which render large electrode-electrolyte interfaces, resulted in good capacitive performance of the supercapacitors. Moreover, a high energy density of ca. 14 Wh kg-1 and a high power density of 6.2 kW kg-1 were achieved for the all-solid-state asymmetric supercapacitors due to the wide cell voltage window. Electronic supplementary information (ESI) available: ESI

  15. Solid-state-reaction synthesis of cotton-like CoB alloy at room temperature as a catalyst for hydrogen generation.

    Wang, Xingpu; Liao, Jinyun; Li, Hao; Wang, Hui; Wang, Rongfang

    2016-08-01

    A novel room-temperature solid-state reaction is developed to synthesize cotton-like CoB alloy (CoBSSR) catalysts with a large specific surface area of 222.4m(2)g(-1). In the hydrolysis of ammonia borane catalyzed by the CoBSSR, the rate of hydrogen generation can reach 68.7mLmin(-1) with a turnover frequency (TOF) value of ca. 6.9Lhydrogenmin(-1)gcatalyst(-1) at 25°C. The TOF value is about 2 times as large as that of CoB alloy prepared by a regular solid-state reaction, which is also much higher than those of the CoB catalysts recently reported in the literature. The activation energy of the hydrolysis of ammonia borane catalyzed by the CoBSSR is as low as 22.78kJmol(-1), hinting that the CoBSSR possesses high catalytic activity, which may be attributed to the large specific surface area and the abundant porous structure. The high catalytic performance, good recoverability and low cost of the CoBSSR enable it to be a promissing catalyst condidate in the hydrolysis of ammonia borane for hydrogen production in commercial application. PMID:27163841

  16. Synthesis of highly white-fluorescent Cu-Ga-S quantum dots for solid-state lighting devices.

    Jo, Dae-Yeon; Yang, Heesun

    2016-01-14

    The synthesis of highly efficient, white-emitting Cu-Ga-S quantum dots (QDs), which possess not only sufficiently wide spectral coverage of blue-to-red but an exceptional quantum yield as high as 75%, is demonstrated. These QDs are further applied as down-converters with a near-UV light-emitting diode (LED) for the fabrication of white QD-LEDs. PMID:26579551

  17. Acidic Properties and Structure-Activity Correlations of Solid Acid Catalysts Revealed by Solid-State NMR Spectroscopy.

    Zheng, Anmin; Li, Shenhui; Liu, Shang-Bin; Deng, Feng

    2016-04-19

    Solid acid materials with tunable structural and acidic properties are promising heterogeneous catalysts for manipulating and/or emulating the activity and selectivity of industrially important catalytic reactions. On the other hand, the performances of acid-catalyzed reactions are mostly dictated by the acidic features, namely, type (Brønsted vs Lewis acidity), amount, strength, and local environment of acid sites. The latter is relevant to their location (intra- vs extracrystalline), and possible confinement and Brønsted-Lewis acid synergy effects that may strongly affect the host-guest interactions, reaction mechanism, and shape selectivity of the catalytic system. This account aims to highlight some important applications of state-of-the-art solid-state NMR (SSNMR) techniques for exploring the structural and acidic properties of solid acid catalysts as well as their catalytic performances and relevant reaction pathway invoked. In addition, density functional theory (DFT) calculations may be exploited in conjunction with experimental SSNMR studies to verify the structure-activity correlations of the catalytic system at a microscopic scale. We describe in this Account the developments and applications of advanced ex situ and/or in situ SSNMR techniques, such as two-dimensional (2D) double-quantum magic-angle spinning (DQ MAS) homonuclear correlation spectroscopy for structural investigation of solid acids as well as study of their acidic properties. Moreover, the energies and electronic structures of the catalysts and detailed catalytic reaction processes, including the identification of reaction species, elucidation of reaction mechanism, and verification of structure-activity correlations, made available by DFT theoretical calculations were also discussed. Relevant discussions will focus primarily on results obtained from our laboratories in the past decade, including (i) quantitative and qualitative acidity characterization utilizing assorted probe molecules

  18. Solid-state circuits

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  19. The complex synthesis and solid state chemistry of ceria-lanthana solid solutions prepared via a hexamethylenetetramine precipitation

    Mixed oxide solid solutions are becoming ever more commercially important across a range of applications. However, their synthesis can be problematical. Here, we show that ceria-lanthana solid solutions can be readily prepared via simple precipitation using hexamethylenetetramine. However, the solution chemistry can be complex, which results in the precipitated particles having a complex structure and morphology. Great care must be taken in both the synthesis and characterisation to quantify the complexity of the product. Even very high heat treatments were not able to produce highly homogeneous materials and X-ray diffractions reveals the non-equilibrium form of particles prepared in this way. Unexpected crystal structures are revealed including a new metastable cubic La2O3 phase. - Graphical abstract: The suggested mechanism for the formation of dual fluorite phase particles, where Step 1 corresponds to room temperature aging, Step 2; heating the solution to 90 deg. C, Step 3; cooling of the solution to room temperature, Step 4; calcination to 500 deg. C, Step 5; calcination to 700 deg. C and Step 6; calcination to 1300 deg. C. The terminology of e.g. La1-xCex(OH)3 is used to indicate the formation of a mixed oxy-hydroxy participate rather than a definitive assignment of stoichiometry. Similarly, La1-yCeyO2 only implies a mixed solid solution. Highlights: → Mol% of prepared Ce-La oxides did not follow that of reactant mol%. → Complex reaction pathway found to be dependent on metal solution concentrations. → At certain concentrations core shell particles were found to form. → A reaction model was produced based on cationic solubility. → Report lanthana solubility higher than previously reported in CeO2.

  20. Development of White-Light Emitting Active Layers in Nitride Based Heterostructures for Phosphorless Solid State Lighting

    Jan Talbot; Kailash Mishra

    2007-12-31

    This report provides a summary of research activities carried out at the University of California, San Diego and Central Research of OSRAM SYLVANIA in Beverly, MA partially supported by a research contract from US Department of Energy, DE-FC26-04NT422274. The main objective of this project was to develop III-V nitrides activated by rare earth ions, RE{sup 3+}, which could eliminate the need for phosphors in nitride-based solid state light sources. The main idea was to convert electron-hole pairs injected into the active layer in a LED die to white light directly through transitions within the energy levels of the 4f{sup n}-manifold of RE{sup 3+}. We focused on the following materials: Eu{sup 3+}(red), Tb{sup 3+}(green), Er{sup 3+}(green), Dy{sup 3+}(yellow) and Tm{sup 3+}(blue) in AlN, GaN and alloys of AlN and GaN. Our strategy was to explore candidate materials in powder form first, and then study their behavior in thin films. Thin films of these materials were to be deposited on sapphire substrates using pulsed laser deposition (PLD) and metal organic vapor phase epitaxy (MOVPE). The photo- and cathode-luminescence measurements of these materials were used to investigate their suitability for white light generation. The project proceeded along this route with minor modifications needed to produce better materials and to expedite our progress towards the final goal. The project made the following accomplishments: (1) red emission from Eu{sup 3+}, green from Tb{sup 3+}, yellow from Dy{sup 3+} and blue from Tm{sup 3+} in AlN powders; (2) red emission from Eu{sup 3+} and green emission from Tb{sup 3+} in GaN powder; (3) red emission from Eu{sup 3+} in alloys of GaN and AlN; (4) green emission from Tb{sup 3+} in GaN thin films by PLD; (5) red emission from Eu{sup 3+} and Tb{sup 3+} in GaN thin films deposited by MOVPE; (6) energy transfer from host to RE{sup 3+}; (7) energy transfer from Tb{sup 3+} to Eu{sup 3+} in AlN powders; (8) emission from AlN powder samples

  1. Solid state physics

    Brewster, Hilary D

    2009-01-01

    Solid state physics is an exhaustive introductory text for the students of physics. Keeping in mind, this book has been prepared to present the subject-matter in an easily understandable way without sacrificing the essential details and principles an yet avoiding redundant matter and unnecessary complications. This book is expected to meet adequately the need of the students for whom it is meant.

  2. Synthesis Of Magnesium-Aluminum Layered Double Hydroxides By Mechanochemical Method And Its Solid State Reaction Kinetics

    Hongbo Y.; Meiling C.; Xiuhui W.; Hong G.

    2015-01-01

    A mechanochemical method is developed in preparing magnesium-aluminum-layered double hydroxides (MgAl-LDHs). This approach includes activation process and diffusion process. In order to verify the LDHs structure and study the reaction kinetics, X-ray diffraction (XRD) patterns, inductively coupled plasma(ICP) and physical adsorption instrument were characterized. The results show that activation time can change the surface of particles and affect the reaction grade. During the diffusion proce...

  3. Production of Sporotrichum thermophile xylanase by solid state fermentation utilizing deoiled Jatropha curcas seed cake and its application in xylooligosachharide synthesis.

    Sadaf, Ayesha; Khare, S K

    2014-02-01

    De-oiled Jatropha curcas seed cake, a plentiful by-product of biodiesel industry was used as substrate for the production of a useful xylanase from Sporotrichum thermophile in solid state fermentation. Under the optimized conditions, 1025U xylanase/g (deoiled seed cake) was produced. The xylanase exhibited half life of 4h at 45°C and 71.44min at 50°C respectively. It was stable in a broad pH range of 7.0-11.0. Km and Vmax were 12.54mg/ml and 454.5U/ml/min respectively. S. thermophile xylanase is an endoxylanase free of exoxylanase activity, hence advantageous for xylan hydrolysis to produce xylooligosachharides. Hydrolysis of oat spelt xylan by S. thermophile xylanase yielded 73% xylotetraose, 15.4% xylotriose and 10% xylobiose. The S. thermophile endoxylanase thus seem potentially useful in the food industries. PMID:24362246

  4. Novel symmetrical coralloid Cu 3D superstructures: Solid-state synthesis from a Cu-carboxylate MOF and their in-situ thermal conversion

    We describe here a one-step solid-state process for the synthesis of metal three-dimensional (3D) superstructures from a metal-organic framework (MOF). Novel symmetrical coralloid Cu 3D superstructures with surface interspersed with clusters of Cu nanoparticles were successfully synthesized by thermolysis of the [Cu3(btc)2] (btc=benzene-1,3,5-tricarboxylato) MOF in a one-end closed horizontal tube furnace (OCTF). The obtained products were characterized by TGA, FT-IR, XRD, EDX, SEM, TEM, HRTEM and SAED. Different reaction conditions were discussed. Furthermore, the synthesized Cu samples were converted into CuO microstructures by in-situ calcination in the air. In addition, the possible formation mechanism was also proposed. This method is a simple and facile route, which builds a direct linkage between metal-carboxylate MOF crystals and metal nano- or microstructures and also opens a new application field of MOFs. - Graphical abstract: Novel symmetrical coralloid Cu 3D superstructures were synthesized by thermolysis of the [Cu3(btc)2] (btc=benzene-1,3,5-tricarboxylato) MOF microcrystals in a one-end closed horizontal tube furnace (OCTF).

  5. Synthesis Of Magnesium-Aluminum Layered Double Hydroxides By Mechanochemical Method And Its Solid State Reaction Kinetics

    Hongbo Y.

    2015-06-01

    Full Text Available A mechanochemical method is developed in preparing magnesium-aluminum-layered double hydroxides (MgAl-LDHs. This approach includes activation process and diffusion process. In order to verify the LDHs structure and study the reaction kinetics, X-ray diffraction (XRD patterns, inductively coupled plasma(ICP and physical adsorption instrument were characterized. The results show that activation time can change the surface of particles and affect the reaction grade. During the diffusion process, reaction time is the most important factor. The reaction energy (ΔQ was calculated that is 6kJ/mol.

  6. Solid-state photochemistry of crystalline pyrazolines: reliable generation and reactivity control of 1,3-biradicals and their potential for the green chemistry synthesis of substituted cyclopropanes.

    Shiraki, Saori; Vogelsberg, Cortnie S; Garcia-Garibay, Miguel A

    2012-12-01

    To expand on the limited number of examples that exist in the literature for the solid-state photodenitrogenation of azoalkanes, a series of crystalline 7-alkyl-2,3,7-triazabicyclo[3.3.0]oct-2-ene-6,8-diones with varying 4,4-substituents were prepared. Their photochemical behavior in solution and in the solid state was dependent on the 4,4-substitution of the 1-pyrazoline ring, with unsubstituted pyrazoline giving a mixture of products both in solution and in the solid state. Diphenyl substituted pyrazolines denitrogenate spontaneously in solution but require light exposure to react quantitatively in the solid state. t-Butyl-phenyl substituted pyrazolines were shown to denitrogenate both chemo- and diastereoselectively in solution and in the solid state to yield a single product in quantitative yield. PMID:22945796

  7. A Solid state accelerator

    We present a solid state accelerator concept utilizing particle acceleration along crystal channels by longitudinal electron plasma waves in a metal. Acceleration gradients of order 100 GV/cm are theoretically possible, but channeling radiation limits the maximum attainable energy to 105 TeV for protons. Beam dechanneling due to multiple scattering is substantially reduced by the high acceleration gradient. Plasma wave dissipation and generation in metals are also discussed

  8. Solid state detector design

    Much has been charged particle detector radiation detector made by the industry, especially those engaged in the development of detection equipment and components. The development and further research will be made solid state detector with silicon material. To be able to detect charged particles (radiation), required the processing of silicon material into the detector material. The method used to make silicon detector material is a lithium evaporations. Having formed an intrinsic region contactor installation process, and with testing. (author)

  9. Synthesis Of Fe Doped LiMn2O4 Cathode Materials For Li Battery By Solid State Reaction

    Horata N.

    2015-06-01

    Full Text Available LiFe0.1Mn1.9O4 is expected as a cathode material for the rechargeable lithium-ion batteries. LiMn2O4 has been received attention because this has advantages such as low cost and low toxicity compared with other cathode materials of LiCoO2 and LiNiO2. However, LiMn2O4 has some problems such as small capacity and no long life. LiMn2O4 is phase transformation at around human life temperature. One of the methods to overcome this problem is to stabilize the spinel structure by substituting Mn site ion in LiMn2O4 with transition metals (Al, Mg, Ti, Ni, Fe, etc.. LiFe0.1Mn1.9O4 spinel was synthesized from Li2CO3, Fe2O3 and MnO2 powder. The purpose of this study is to report the optimal condition of Fe doped LiFe0.1Mn1.9O4. Li2CO3, Fe2O3, and MnO2 mixture powder was heated up to 1173 K by TG-DTA. Li2CO3 was thermal decomposed, and CO2 gas evolved, and formed Li2O at about 800 K. LiFe0.1Mn1.9O4 was synthesized from a consecutive reaction Li2O, Fe2O3 and MnO2 at 723 ~ 1023 K. Active energy is calculated to 178 kJmol−1 at 723 ~ 1023 K. The X-ray powder diffraction pattern of the LiFe0.1Mn1.9O4 heated mixture powder at 1023 K for 32 h in air flow was observed.

  10. Solid state synthesis, characterization, surface and catalytic properties of Pr2CoO4 and Pr2NiO4 catalyst

    Full text: The most interesting non-stoichiometric oxides are found in transition metal and rare earth oxides at higher temperatures. The role of Solid State properties in the catalysis using mixed metal oxide as catalyst have wide applications in fertilizer, Petro-chemical, Pharmaceutical, cosmetic, paint detergents, plastics and food-stuff industries and these are also resistive towards acids and alkalies. The use of catalyst has opened up new process routes or revolutioned the existing process in terms of economics and efficiency and has radically changed the industrial scenario. The use of catalyst is so pervasive today that nearly 70 % of modern chemical processes are based on it at some stage or other and 90% new processes developed are catalytic nature. A series of non-stoichiometric spinel type of oxide catalyst of Praseodymium with cobalt and nickel were synthesized by their oxalates through Solid State reaction technique at different activation temperatures i.e. 600, 700, 800 and 900 deg C. The characterization of catalyst was done by XRD, FTIR and ESR methods. X-ray powder diffraction study shows that catalysts are made up of well grown crystallinities mostly in single phase crystal and system is of orthorhombic structure. FTIR is related to inadequate decomposition of oxalate ion from the Catalyst. The kinetic decomposition of Urea was employed as a model reaction to study the catalytic potentiality of different catalysts. Surface and Catalytic Properties of catalysts were measured. A relation between activation temperature and surface properties like excess surface oxygen (E.S.O.), surface acidity and surface area was observed. A linear relationship between the surface area of the catalyst and the amount of ammonia gas evolved per gm of the sample was observed also. Nickel containing catalysts were found a bit more catalytic active in comparison to cobalt oxide catalysts. Transition metal ions (i.e. Ni2+and Co2+ ions) are mainly responsible for

  11. Solid state synthesis of SrAl2O4:Mn2+ co-doped with Nd3+ phosphor and its optical properties

    The optical properties of alkaline earth aluminates doped with rare earth ions have received much attention in the last years and this is due to their chemical stability, long-afterglow (LAG) phosphorescence and high quantum efficiency. However, there is a lack of understanding about the nature of the rare earth ion trapping sites and the mechanisms which could activate and improve the emission centers in these materials. Therefore a new phosphor material composition, SrAl2O4:Mn2+, co-doped with Nd3+ was synthesized by a traditional solid-state reaction method. The influence of transition metal and rare earth doping on crystal structure and its luminescence properties have been investigated by using X-ray diffraction (XRD), Raman scattering, Photoluminescence (PL) and Radioluminescence (RL). Analysis of the related diffraction patterns has revealed a major phase characteristic of the monoclinic SrAl2O4 compound. Small amounts of the dopants MnCO3 and Nd2O3 have almost no effect on the crsytalline phase composition. Characteristic absorption bands from Nd3+ 4f–4f transitions in the spectra can be assigned to the transitions from the ground state 4I9/2 to the excited states. The luminescence of Mn2+ activated SrAl2O4 exhibits a broad green emission band from the synthesized phosphor particles under different excitation sources. This corresponds to the spin-forbidden transition of the d-orbital electron associated with the Mn2+ ion. In photo- and radio-luminescence spectra, Nd3+ 4f–4f transition peaks were observed. The emitted radiations for different luminescence techniques were dominated by 560, 870, 1057 and 1335 nm peaks in the visible and NIR regions as a result of 4I9/2→4G7/2 and 4F3/2→4IJ (J=9/2, 11/2 and 13/2) transitions of Nd3+ ions, respectively. Multiple emission lines observed at each of these techniques are due to the crystal field splitting of the ground state of the emitting ions. The nature of the emission lines is discussed. -- Highlights:

  12. Solid state physics

    Grosso, Giuseppe

    2013-01-01

    Solid State Physics is a textbook for students of physics, material science, chemistry, and engineering. It is the state-of-the-art presentation of the theoretical foundations and application of the quantum structure of matter and materials. This second edition provides timely coverage of the most important scientific breakthroughs of the last decade (especially in low-dimensional systems and quantum transport). It helps build readers' understanding of the newest advances in condensed matter physics with rigorous yet clear mathematics. Examples are an integral part of the text, carefully de

  13. Solid state physics

    Burns, Gerald

    2013-01-01

    The objective of Solid State Physics is to introduce college seniors and first-year graduate students in physics, electrical engineering, materials science, chemistry, and related areas to this diverse and fascinating field. I have attempted to present this complex subject matter in a coherent, integrated manner, emphasizing fundamental scientific ideas to give the student a strong understanding and ""feel"" for the physics and the orders of magnitude involved. The subject is varied, covering many important, sophisticated, and practical areas, which, at first, may appear unrelated but which ar

  14. Solid state phenomena

    Lawrance, R

    1972-01-01

    Solid State Phenomena explores the fundamentals of the structure and their influence on the properties of solids. This book is composed of five chapters that focus on the electrical and thermal conductivities of crystalline solids. Chapter 1 describes the nature of solids, particularly metals and crystalline materials. This chapter also presents a model to evaluate crystal structure, the forces between atom pairs, and the mechanism of plastic and elastic deformation. Chapter 2 demonstrates random vibrations of atoms in a solid using a one-dimensional array, while Chapter 3 examines the resista

  15. Rapid and Energy-Saving Microwave-Assisted Solid-State Synthesis of Pr(3+)-, Eu(3+)-, or Tb(3+)-Doped Lu2O3 Persistent Luminescence Materials.

    Pedroso, Cássio C S; Carvalho, José M; Rodrigues, Lucas C V; Hölsä, Jorma; Brito, Hermi F

    2016-08-01

    Persistent luminescence materials Lu2O3:R(3+),M (Pr,Hf(IV); Eu; or Tb,Ca(2+)) were successfully and rapidly (22 min) prepared by microwave-assisted solid-state synthesis (MASS) using a carbon microwave susceptor and H3BO3 as flux. Reaction times are reduced by up to 93% over previous synthetic methods, without special gases application and using a domestic microwave oven. All materials prepared with H3BO3 flux exhibit LuBO3 impurities that were quantified by Rietveld refinement from synchrotron radiation X-ray powder diffraction patterns. The flux does not considerably affect the crystalline structure of the C-Lu2O3, however. Scanning electron micrographs suggest low surface area when H3BO3 flux is used in the materials' synthesis, decreasing the amount of surface hydroxyl groups in Lu2O3 and improving the luminescence intensity of the phosphors. The carbon used as the susceptor generates CO gas, leading to complete reduction of Tb(IV) to Tb(3+) and partial conversion of Pr(IV) to Pr(3+) present in the Tb4O7 and Pr6O11 precursors, as indicated by X-ray absorption near-edge structure data. Persistent luminescence spectra of the materials show the red/near-IR, reddish orange, and green emission colors assigned to the 4f(n) → 4f(n) transitions characteristics of Pr(3+), Eu(3+), and Tb(3+) ions, respectively. Differences between the UV-excited and persistent luminescence spectra can be explained by the preferential persistent luminescence emission of R(3+) ion in the S6 site rather than R(3+) in the C2 site. In addition, inclusion of Hf(IV) and Ca(2+) codopants in the Lu2O3 host increases the emission intensity and duration of persistent luminescence due to generation of traps caused by charge compensation in the lattice. Photonic materials prepared by MASS with H3BO3 flux show higher persistent luminescence performance than those prepared by the ceramic method or MASS without flux. Color tuning of persistent luminescence in Lu2O3:R(3+),M provides potential

  16. Solid-State Personal Dosimetry

    Wrbanek, John D.; Fralick, Gustave C.; Wrbanek, Susan Y.

    2005-01-01

    This document is a web site page, and a data sheet about Personal protection (i.e., space suits) presented to the Radiation and Micrometeoroid Mitigation Technology Focus Group meeting. The website describes the work of the PI to improve solid state personal radiation dosimetry. The data sheet presents work on the active personal radiation detection system that is to provide real-time local radiation exposure information during EVA. Should undue exposure occur, knowledge of the dynamic intensity conditions during the exposure will allow more precise diagnostic assessment of the potential health risk to the exposed individual.

  17. Core-level and valence band photoemission study of La1-xSrxMnO3 perovskite oxide powders synthesized by mechanically and thermally activated solid-state reaction

    High-resolution core-level and valence band x-ray photoemission spectroscopy measurements were performed on La1-xSrxMnO3 perovskite oxide powders synthesized for applications in solid-oxide fuel cells by high-temperature solid-state reaction (x = 0.3 and 0.19) and by room-temperature mechanical activation of the precursors (x = 0.3). A structure in the valence band at about 1 eV below the Fermi level was clearly observed and assigned to the emission from the Mn 3d-derived eg1↑ states, thereby allowing the extraction of information about correlation effects in this type of material. Both the core-level and valence band spectral features were found to be independent of the choice of synthesis route. This finding indicates that mechanical activation, due to its lower synthesis temperature, can represent a valid alternative method of synthesis allowing a better control of the microstructure. (author)

  18. Solid-state diffusion in amorphous zirconolite

    Yang, C.; Dove, M. T.; Trachenko, K. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Zarkadoula, E. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6138 (United States); Todorov, I. T. [STFC Daresbury Laboratory, Warrington WA4 1EP (United Kingdom); Geisler, T. [Steinmann-Institut für Geologie, Mineralogie und Paläontologie, University of Bonn, D-53115 Bonn (Germany); Brazhkin, V. V. [Institute for High Pressure Physics, RAS, 142190 Moscow (Russian Federation)

    2014-11-14

    We discuss how structural disorder and amorphization affect solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but does not change the activation energy in the density range considered. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

  19. Preparation of a highly active Fe-ZSM-5 catalyst through solid-state ion exchange for the catalytic decomposition of N{sub 2}O

    Rauscher, M.; Kesore, K.; Moennig, R.; Schwieger, W. [Institut fuer Technische Chemie und Makromolekulare Chemie, Martin-Luther-Universitaet Halle-Wittenberg, Schlossberg 2, D-06108 Halle/S (Germany); Tissler, A. [ALSI-PENTA Zeolithe GmbH, Alustrasse 50-52, D-92421 Schwandorf (Germany); Turek, T. [Institut fuer Chemische Verfahrenstechnik, Universitaet Karlsruhe TH, Kaiserstrasse 12, D-76128 Karlsruhe (Germany)

    1999-08-16

    This work describes a new and simple preparation method for Fe-ZSM-5 pentasil-zeolites through solid-state ion exchange process. The zeolite catalysts thus prepared exhibit high activity during the catalytic decomposition of N{sub 2}O in the absence of reducing agents. The aimed choice of using FeSO{sub 4}x7H{sub 2}O and NH{sub 4}-ZSM-5 as starting materials consisted of forming such products (ammonium salts) after the ion exchange process that can be completely removed through thermal treatment. The complete preparation process leading to the formation of catalytically active iron species inside the zeolite takes place in two steps at two distinguished temperatures, respectively. The first step during which the solid-state ion exchange takes place has been carried out through two different routes, in air and in vacuum, in search for an enhanced catalytic activity. The second step has to be necessarily done under anaerobic conditions. XRD measurements have revealed the presence of hematite in samples with a Fe(II)/Al ratio above 0.5. The different numbers of Broensted sites occupied by the iron species in the catalysts with different Fe contents have also been determined

  20. Solid state plasmas

    Manfredi, Giovanni

    2014-01-01

    Magnetic fusion devices operate at regimes characterized by extremely high temperatures and low densities, for which the charged particles motion is well described by classical mechanics. This is not true, however, for solid-state metallic objects: their density approaches $10^{28} \\rm m^{-3}$, so that the average interparticle distance is shorter than the de Broglie wavelength, which characterizes the spread of the electron wave function. Under these conditions, the conduction electrons behave as a true quantum plasma even at room temperature. Here, we shall illustrate the impact of quantum phenomena on the electron dynamics in metallic objects of nanometric size, particularly thin metallic films excited by short laser pulses. Further, we will discuss more recent results on regimes that involve spin and relativistic effects.

  1. Solid state reaction synthesis and optical spectroscopy of ferroelectric (Gd{sub 1-x}Ln{sub x}){sub 2}(MoO{sub 4}){sub 3}; with Ln = Yb or Tm

    Lin Zhoubin; Han Xiumei [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, c/Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain); Zaldo, Carlos, E-mail: cezaldo@icmm.csic.e [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, c/Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain)

    2010-03-04

    A solid state synthesis route was used to prepare (Gd{sub 1-x}Ln{sub x}){sub 2}(MoO{sub 4}){sub 3}, Ln = Yb or Tm, compounds with ferroelectric Pba2 crystal structure. It has been observed that this phase is the only one crystallized during 1123 K annealing for x {<=} 0.12 for Yb and x {<=} 0.3 for Tm. Above these concentration limits the simultaneous formation of trihydrated Ln{sub 2}(MoO{sub 4}){sub 3}, Ln = Yb or Tm, is observed. Up to these concentrations Yb and Tm incorporations do not degrade the SHG efficiency. The position of Yb{sup 3+} and Tm{sup 3+} energy levels involved in laser emission processes were determined by 5 K spectroscopy. The 300 K pumping and emission spectral distributions and excited level lifetime have been determined with the purpose of future applications as self-activated periodically poled ferroelectric laser and non-linear media.

  2. Sm3+-activated gadolinium molybdate: an intense red-emitting phosphor for solid-state lighting based on InGaN LEDs

    Sm3+-activated gadolinium molybdate, Gd2(MoO4)3:Sm3+ red-emitting phosphor was prepared by conventional solid-state method. The structure, morphology, and luminescent properties of these powder samples have been investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and fluorescent spectrophotometry, respectively. The as-obtained phosphor has a monoclinic structure with single crystalline phase. Its mean particle size is about 6-8 μm with pseudo-pompon shape and large surface area, which is suitable for manufacture of white LEDs. The phosphor can be efficiently excited by incident light of 348-445 nm, well matched with the output wavelength of a near-UV InGaN-based chip, and re-emits an intense red light peaking at 650 nm. By combing this phosphor with a 405 nm-emitting InGaN chip, a red LED was fabricated, so that the applicability of this novel phosphor to white LEDs was confirmed. It is considered to be an efficient red-emitting conversion phosphor for solid-state lighting based on InGaN LEDs.

  3. Solid state chemistry an introduction

    Smart, Lesley E

    2012-01-01

    ""Smart and Moore are engaging writers, providing clear explanations for concepts in solid-state chemistry from the atomic/molecular perspective. The fourth edition is a welcome addition to my bookshelves. … What I like most about Solid State Chemistry is that it gives simple clear descriptions for a large number of interesting materials and correspondingly clear explanations of their applications. Solid State Chemistry could be used for a solid state textbook at the third or fourth year undergraduate level, especially for chemistry programs. It is also a useful resource for beginning graduate

  4. Luminescence and the solid state

    Ropp, Richard C

    2013-01-01

    Since the discovery of the transistor in 1948, the study of the solid state has been burgeoning. Recently, cold fusion and the ceramic superconductor have given cause for excitement. There are two approaches possible to this area of science, namely, that of solid state physics and solid state chemistry, although both overlap extensively. The former is more concerned with electronic states in solids (including electromagnetics) whereas the latter is more concerned with interactions of atoms in solids. The area of solid state physics is well documented, however, there are very few texts which de

  5. A Solid State Pyranometer

    Dumitrescu, Anca Laura; Paulescu, Marius; Ercuta, Aurel

    2015-12-01

    The construction of a solid state device-based pyranometer designated to broadband irradiance measurements is presented in this paper. The device is built on the physical basis that the temperature difference between two bodies of identical shape and external surface area, identically exposed to the incident radiation, but having different absorption and heat transfer coefficients (e.g. one body is painted white and the other is painted black), is proportional to the incident irradiance. This proportionality may be put in evidence if the two bodies consisting of identical arrays of correspondingly painted semiconductor diodes, due to the thermal behaviour of their p-n junction. It is theoretically predicted and experimentally confirmed that the voltage drop across a diode passed through a constant forward current linearly decreases with the temperature of the junction. In other words, a signal proportional to the irradiance of the light source may be obtained via conventional analog electronics. The calibration of the apparatus, as performed by means of a professional device (LP PYRA 03), indicates a good linearity.

  6. Solid state magnetic refrigerator

    Highlights: ► One proposes a magnetic refrigerator not requiring the use of fluids. ► Materials whose thermal conductivities depend on an applied magnetic field are used. ► Numerical simulations show that the coefficient of performance attained reaches 1.5. ► The device can be triggered from cooler to heat source by varying the frequency. - Abstract: The viability and operation of a fully solid state magnetic refrigeration system with envisaged applications on chip, sensor and device cooling is here tested using numerical simulations. The proposed system relies on the combined use of materials displaying the magnetocaloric effect and of materials whose thermal conductivities are controlled by an external magnetic field. This allows the switching of the heat flow direction in sync with the temperature variation of the magnetocaloric material, removing the necessity to use fluids which has for long hindered the implementation of magnetic refrigeration. We have found the optimum operating conditions of the proposed refrigerator, for which a cooling power density of ∼2.75 W cm−2 was obtained for an operating temperature of ∼296 K, using Gadolinium as the magnetocaloric material and an applied magnetic field of 1 T. The coefficient of performance (COP) achieved by this refrigerator was found to be COP ∼1.5, making it a viable alternative to thermoelectric refrigeration.

  7. Inside Solid State Drives (SSDs)

    Micheloni, Rino; Eshghi, Kam

    2013-01-01

    Solid State Drives (SSDs) are gaining momentum in enterprise and client applications, replacing Hard Disk Drives (HDDs) by offering higher performance and lower power. In the enterprise, developers of data center server and storage systems have seen CPU performance growing exponentially for the past two decades, while HDD performance has improved linearly for the same period. Additionally, multi-core CPU designs and virtualization have increased randomness of storage I/Os. These trends have shifted performance bottlenecks to enterprise storage systems. Business critical applications such as online transaction processing, financial data processing and database mining are increasingly limited by storage performance. In client applications, small mobile platforms are leaving little room for batteries while demanding long life out of them. Therefore, reducing both idle and active power consumption has become critical. Additionally, client storage systems are in need of significant performance improvement as well ...

  8. Radio Frequency Solid State Amplifiers

    Jacob, J

    2015-01-01

    Solid state amplifiers are being increasingly used instead of electronic vacuum tubes to feed accelerating cavities with radio frequency power in the 100 kW range. Power is obtained from the combination of hundreds of transistor amplifier modules. This paper summarizes a one hour lecture on solid state amplifiers for accelerator applications.

  9. Synthesis of H(x)Li(1-x)LaTiO4 from quantitative solid-state reactions at room temperature.

    Yip, Thomas W S; Cussen, Edmund J; MacLaren, Donald A

    2010-02-01

    The layered perovskite HLaTiO(4) reacts stoichiometrically with LiOH.H(2)O at room temperature to give targeted compositions in the series H(x)Li(1-x)LaTiO(4). Remarkably, the Li(+) and H(+) ions are quantitatively exchanged in the solid state and this allows stoichiometric control of ion exchange for the first time in this important series of compounds. PMID:20087491

  10. Synthesis and sintering of Li4SiO4 powder from rice husk ash by solution combustion method and its comparison with solid state method

    Graphical abstract: Preparation of white RHA and Li4SiO4 powders using solution combustion technique. Highlights: • Li4SiO4 prepared by solution combustion method using rice husk ash as silica source. • Phase pure, submicron size Li4SiO4 powders prepared at 650 °C. • Li4SiO4 is also prepared by solid state method for comparison of different properties. • Powder can be sintered at 900 °C with acceptable density and small grain size. • Absence of closed pore achieved in sintered specimen. -- Abstract: Phase pure lithium orthosilicate (Li4SiO4) was prepared by the solution – combustion technique as well as solid state method using rice husk ash (RHA) as silica source. It was found that by controlling the metal to citrate ratio of the starting solution, phase pure powder can be prepared at 650 °C. Whereas in solid state method, calcination at 800 °C was required to achieve phase purity. The particle size of Li4SiO4 powder (prepared at C/M = 1.4) was found to be 100–200 nm with low surface area (1.83 m2/gm). It was found that Li4SiO4 powder can be sintered at a temperature as low as 900 °C with a density ∼83% of the theoretical density. In case of solid state method prepared powder, maximum 80% of the theoretical density could be achieved. Phase stability in the sintered sample was studied

  11. Optimization of the solid-state fermentation and properties of a polysaccharide from Paecilomyces cicadae (Miquel Samson and its antioxidant activities in vitro.

    Xueyong Ren

    Full Text Available The culture conditions for the yield of a polysaccharide (PCPS produced by Paecilomyces cicadae (Miquel Samson on solid-state fermentation were investigated using response surface methodology (RSM. Plackett-Burman design (PBD was applied to screen out significant factors, followed by the paths of steepest ascent to move to the nearest region of maximum response. Then Box-Behnken design (BBD was conducted to optimize the final levels of the culture conditions. After analyzing the regression equation and the response surface contour plots, relative humidity 56.07%, inoculum 13.51 mL/100 g and temperature 27.09°C were found to be the optimal key parameters for PCPS production. The maximum predicted yield of PCPS was 10.76 mg/g under the optimized conditions. The resulting PCPS (FPCPS generated at optimal conditions was purified by chromatography column and found to be composed of mannose (43.2%, rhamnose (32.1%, xylose (14.5% and arabinose (10.2%. Based on the size exclusion chromatography combined with multi-angle laser light scattering (SEC-MALLS analysis, FPCPS adopted a Gaussian coil conformation in 0.1 M NaNO3 solution with 3.75 × 10(6 g/mol of the weight-average molar mass (Mw and 41.1 nm of the root-mean square radius (Rg(2z (1/2. Furthermore, both of the polysaccharides were revealed to have strong antioxidant activities by evaluating in DPPH radical, superoxide radicals and hydroxyl radical assay. These data suggest the polysaccharides of Paecilomyces cicadae (Miquel Samson produced by solid-state fermentation could be explored as potential natural antioxidants.

  12. Deformation of partially pumped active mirrors for high average-power diode-pumped solid-state lasers.

    Albach, Daniel; LeTouzé, Geoffroy; Chanteloup, Jean-Christophe

    2011-04-25

    We discuss the deformation of a partially pumped active mirror amplifier as a free standing disk, as implemented in several laser systems. We rely on the Lucia laser project to experimentally evaluate the analytical and numerical deformation models. PMID:21643092

  13. Utilizing assumption for project of stand for solid state targets activation on inner beams of AIC-144 cyclotron

    General assumptions for project of target activation stand at AIC-144 cyclotron are presented. The project predicts production of 67Ga, 111In, 201Tl, 139Ce, 88Y, 123I and 211At isotopes using various target backings. Directions concerning target cooling and beam parameters are also described

  14. Investigation of Antimicrobial Activity and Statistical Optimization of Bacillus subtilis SPB1 Biosurfactant Production in Solid-State Fermentation

    Dhouha Ghribi

    2012-01-01

    Full Text Available During the last years, several applications of biosurfactants with medical purposes have been reported. Biosurfactants are considered relevant molecules for applications in combating many diseases. However, their use is currently extremely limited due to their high cost in relation to that of chemical surfactants. Use of inexpensive substrates can drastically decrease its production cost. Here, twelve solid substrates were screened for the production of Bacillus subtilis SPB1 biosurfactant and the maximum yield was found with millet. A Plackett-Burman design was then used to evaluate the effects of five variables (temperature, moisture, initial pH, inoculum age, and inoculum size. Statistical analyses showed that temperature, inoculum age, and moisture content had significantly positive effect on SPB1 biosurfactant production. Their values were further optimized using a central composite design and a response surface methodology. The optimal conditions of temperature, inoculum age, and moisture content obtained under the conditions of study were 37°C, 14 h, and 88%, respectively. The evaluation of the antimicrobial activity of this compound was carried out against 11 bacteria and 8 fungi. The results demonstrated that this biosurfactant exhibited an important antimicrobial activity against microorganisms with multidrug-resistant profiles. Its activity was very effective against Staphylococcus aureus, Staphylococcus xylosus, Enterococcus faecalis, Klebsiella pneumonia, and so forth.

  15. Phosphate Phosphors for Solid-State Lighting

    Shinde, Kartik N; Swart, H C; Park, Kyeongsoon

    2012-01-01

    The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  16. On the Mesoporogen-Free Synthesis of Single-Crystalline Hierarchically Structured ZSM-5 Zeolites in a Quasi-Solid-State System.

    Ge, Tongguang; Hua, Zile; He, Xiaoyun; Lv, Jian; Chen, Hangrong; Zhang, Lingxia; Yao, Heliang; Liu, Ziwei; Lin, Chucheng; Shi, Jianlin

    2016-06-01

    Hierarchically structured zeolites (HSZs) have gained much academic and industrial interest owing to their multiscale pore structures and consequent excellent performances in varied chemical processes. Although a number of synthetic strategies have been developed in recent years, the scalable production of HSZs single crystals with penetrating and three-dimensionally (3-D) interconnected mesopore systems but without using a mesoscale template is still a great challenge. Herein, based on a steam-assisted crystallization (SAC) method, we report a facile and scalable strategy for the synthesis of single-crystalline ZSM-5 HSZs by using only a small amount of micropore-structure-directing agents (i.e., tetrapropylammonium hydroxide). The synthesized materials exhibited high crystallinity, a large specific surface area of 468 m(2)  g(-1) , and a pore volume of 0.43 cm(3)  g(-1) without sacrificing the microporosity (≈0.11 cm(3)  g(-1) ) in a product batch up to 11.7 g. Further, a kinetically controlled nucleation-growth mechanism is proposed for the successful synthesis of single-crystalline ZSM-5 HSZs with this novel process. As expected, compared with the conventional microporous ZSM-5 and amorphous mesoporous Al-MCM-41 counterparts, the synthesized HSZs exhibited significantly enhanced activity and stability and prolonged lifetime in model reactions, especially when bulky molecules were involved. PMID:27106662

  17. Solid-state laser engineering

    Koechner, Walter

    1999-01-01

    Solid-State Laser Engineering, written from an industrial perspective, discusses in detail the characteristics, design, construction, and performance of solid-state lasers. Emphasis is placed on engineering and practical considerations; phenomenological aspects using models are preferred to abstract mathematical derivations. This new edition has extensively been updated to account for recent developments in the areas of diode-laser pumping, laser materials, and nonlinear crystals. Walter Koechner received a doctorate in Electrical Engineering from the University of Technology in Vienna, Austria, in 1965. He has published numerous papers in the fields of solid-state physics, optics, and lasers. Dr. Koechner is founder and president of Fibertek, Inc., a research firm specializing in the design, development, and production of advanced solid-state lasers, optical radars, and remote-sensing systems.

  18. Solid-state laser engineering

    Koechner, Walter

    1996-01-01

    Solid-State Laser Engineering, written from an industrial perspective, discusses in detail the characteristics, design, construction, and performance of solid-state lasers. Emphasis is placed on engineering and practical considerations; phenomenological aspects using models are preferred to abstract mathematical derivations. This new edition has extensively been updated to account for recent developments in the areas of diode-laser pumping, mode locking, ultrashort-pulse generation etc. Walter Koechner received a doctorate in Electrical Engineering from the University of Technology in Vienna, Austria, in 1965. He has published numerous papers in the fields of solid-state physics, optics, and lasers. Dr. Koechner is founder and president of Fibertek, Inc., a research firm specializing in the design, development, and production of advanced solid-state lasers, optical radars, and remote-sensing systems.

  19. Enhancement of antioxidant activity, total phenolic and flavonoid content of black soybeans by solid state fermentation with Bacillus subtilis BCRC 14715.

    Juan, Ming-Yen; Chou, Cheng-Chun

    2010-08-01

    In the present study, a solid state fermentation of black soybeans with Bacillus subtilis BCRC 14715 was performed. The effect of fermentation on the changes of total phenolic and flavonoid content and antioxidant activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect, and Fe(2+)-chelating ability exerted by various solvent (water, 80% methanol, 80% ethanol, 80% acetone) extracts of black soybeans was examined. It was found that fermentation enhanced the total phenolic and flavonoid content as well as antioxidant activity of the black soybean extract. Among the various extracts examined, the acetone extract of fermented black soybeans showed the highest total phenolic and flavonoid content. The acetone extract and the methanol extract of fermented black soybeans showed the highest DPPH free radical-scavenging effect and Fe(2+)-chelating ability, respectively. Analysis of extraction yields showed that the active principle associated with the DPPH radical-scavenging effect was most efficiently extracted from black soybeans using water, regardless of fermentation. Water and methanol effectively extract the Fe(2+)-chelating principles from non-fermented and fermented black soybeans, respectively. PMID:20510775

  20. Solid State Photovoltaic Research Branch

    1990-09-01

    This report summarizes the progress of the Solid State Photovoltaic Research Branch of the Solar Energy Research Institute (SERI) from October 1, 1988, through September 30,l 1989. Six technical sections of the report cover these main areas of SERIs in-house research: Semiconductor Crystal Growth, Amorphous Silicon Research, Polycrystalline Thin Films, III-V High-Efficiency Photovoltaic Cells, Solid-State Theory, and Laser Raman and Luminescence Spectroscopy. Sections have been indexed separately for inclusion on the data base.

  1. Solid-state laser engineering

    Koechner, Walter

    1988-01-01

    Solid-State Laser Engineering is written from an industrial perspective and discusses in detail the characteristics, design, construction and practical problems of solid-state lasers. Emphasis is placed on engineering and practical considerations, with a phenomenological treatment using modelsbeing preferred to abstract mathematical derivations. This new edition has been updated and revised to include important developments, concepts and technologies that have emerged since the publication of the first edition.

  2. Solid State Division progress report for period ending March 31, 1997

    Green, P.H.; Hinton, L.W. [eds.

    1997-12-01

    This report covers research progress in the Solid State Division from April 1, 1995, through March 31, 1997. During this period, the division conducted a broad, interdisciplinary materials research program in support of Department of Energy science and technology missions. The report includes brief summaries of research activities in condensed matter theory, neutron scattering, synthesis and characterization of materials, ion beam and laser processing, and the structure of solids and surfaces. An addendum includes listings of division publications and professional activities.

  3. Improvement of Medium Chain Fatty Acid Content and Antimicrobial Activity of Coconut Oil via Solid-State Fermentation Using a Malaysian Geotrichum candidum

    Anahita Khoramnia

    2013-01-01

    Full Text Available Coconut oil is a rich source of beneficial medium chain fatty acids (MCFAs particularly lauric acid. In this study, the oil was modified into a value-added product using direct modification of substrate through fermentation (DIMOSFER method. A coconut-based and coconut-oil-added solid-state cultivation using a Malaysian lipolytic Geotrichum candidum was used to convert the coconut oil into MCFAs-rich oil. Chemical characteristics of the modified coconut oils (MCOs considering total medium chain glyceride esters were compared to those of the normal coconut oil using ELSD-RP-HPLC. Optimum amount of coconut oil hydrolysis was achieved at 29% moisture content and 10.14% oil content after 9 days of incubation, where the quantitative amounts of the modified coconut oil and MCFA were 0.330 mL/g of solid media (76.5% bioconversion and 0.175 mL/g of solid media (53% of the MCO, respectively. MCOs demonstrated improved antibacterial activity mostly due to the presence of free lauric acid. The highest MCFAs-rich coconut oil revealed as much as 90% and 80% antibacterial activities against Staphylococcus aureus and Escherichia coli, respectively. The results of the study showed that DIMOSFER by a local lipolytic G. candidum can be used to produce MCFAs as natural, effective, and safe antimicrobial agent. The produced MCOs and MCFAs could be further applied in food and pharmaceutical industries.

  4. Luminescence Properties of Self-Activated Mm(VO4)2 (M = Mg, Ca, Sr, and Ba) Phosphors Synthesized by Solid-State Reaction Method.

    Min, Xin; Huang, Zhaohui; Fang, Minghao; Liu, Yan'gai; Tang, Chao; Wu, Xiaowen

    2016-04-01

    In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V-V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs). PMID:27451689

  5. Solid state electrolyte systems

    Pederson, L.R.; Armstrong, B.L.; Armstrong, T.R. [Pacific Northwest Lab., Richland, WA (United States)] [and others

    1997-12-01

    Lanthanum gallates are a new family of solid electrolytes that exhibit high ionic conductivity and are stable to high temperatures. Compositions have been developed that are as much as a factor of two more conductive than yttria-stabilized zirconia at a given temperature, through partial replacement of lanthanum by calcium, strontium, and/or barium and through partial replacement of gallium by magnesium. Oxide powders were prepared using combustion synthesis techniques developed in this laboratory; these were sintered to >95% of theoretical density and consisted of a single crystalline phase. Electrical conductivities, electron and ion transference numbers, thermal expansion, and phase behavior were evaluated as a function of temperature and oxygen partial pressure. A key advantage of the use of lanthanum gallate electrolytes in solid oxide fuel cells is that the temperature of operation may be lowered to perhaps 800 C, yet provide approximately the same power density as zirconia-based cells operating at 1000 C. Ceramic electrolytes that conduct both oxygen ions and electrons are potentially useful to passively separate pure oxygen from an air source at low cost. In such materials, an oxygen ion flux in one direction is charge-compensated by an opposing electron flux. The authors have examined a wide range of mixed ion and electron conducting perovskite ceramics in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, where M = Sr, Ca, and Ba, and N = Pr, Mn, Ni, Cu, Ti, and Al, as well as mixed conducting brownmillerite ceramics, and have characterized oxygen permeation behavior, defect chemistry, structural and phase stability, and performance as cathodes.

  6. Direct solid-state synthesis at high pressures of new mixed-metal oxynitrides: RZrO(2)N (R = Pr, Nd, and Sm).

    Yang, Minghui; Rodgers, Jennifer A; Middler, Lawrence C; Oró-Solé, Judith; Jorge, A Belén; Fuertes, Amparo; Attfield, J Paul

    2009-12-21

    New oxynitrides of RZrO(2)N (R = Pr, Nd, and Sm) have been synthesized via a direct solid-state reaction of R(2)O(3) with Zr(2)ON(2) at 1200-1500 degrees C under 2-3 GPa pressure. Powder X-ray diffraction shows that all three phases adopt an orthorhombic Pnma perovskite superstructure [a = 5.8537(1) A, b = 8.1707(1) A, and c = 5.7093(1) A for NdZrO(2)N] and the structural distortion increases with decreasing R(3+) ionic radius. This method may enable new mixed-metal oxynitrides to be synthesized without the use of nitriding gas atmospheres. PMID:19911817

  7. Synthesis and structural characterization of some Pb(B$^{'}_{1/3}$Nb2/3)O3 type materials by two-stage solid-state route

    Mukul Pastor; P K Bajpai; R N P Choudhary

    2005-06-01

    Two-stage columbite solid state reaction route has been used for the preparation of Pb (B$^{'}_{1/3}$Nb2/3)O3 materials (B′ = Mg, Ni and Cd). The columbite precursor phase was structurally characterized using diffraction data. MgNb2O6, NiNb2O6 and CdNb2O6 show orthorhombic structures i.e. pure columbite phase. Final phase materials get stabilized in mixed phase. The diffraction pattern shows that it is a mixture of cubic pyrochlore and perovskite phase. Percentage of perovskite phase was calculated using the band intensities of (110) perovskite and (222) pyrochlore peaks. The calculated percentages show the dominant perovskite phase. Possible reasons for mixed phase are discussed.

  8. σ-Hole bonding in 15N-labeled N-Benzyl- N-(4-iodo-tetrafluorobenzyl)-amine: Synthesis, crystal structure and solid-state structure calculations

    Raouafi, Noureddine; Mayer, Peter; Boujlel, Khaled; Schöllhorn, Bernd

    2011-03-01

    Reductive amination of 4-iodo-tetrafluorobenzaldehyde 2 and 15N-enriched benzylamine yielded the title compound 1. Single crystal X-ray diffraction (XRD) revealed that the product crystallizes in the triclinic system of the P-1 space group. The structure is consisting of infinite one-dimensional chair like chains, based on intermolecular N···I halogen bonding. Only intermolecular weak hydrogen bonds N sbnd H···F and C sbnd H···F are observed. Representative XRD data have been compared to the results of theoretical semi-empirical calculations in the solid-state obtained using the PM6 method. Charges of I, N and F atoms are calculated from Natural Bond Orbital (NBO) and Electrostatic Potential Surface maps have been estimated by applying second-order Møller-Plesset (MP2) perturbation theory, and confirmed clearly the assumption of σ-hole bonding formation.

  9. Solid state reaction synthesis and luminescence properties of Dy{sup 3+}-doped Gd{sub 2}Mo{sub 3}O{sub 9} phosphor

    Zhang Lihui [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Zhong Haiyang, E-mail: haae007@163.com [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Li Xiangping; Cheng Lihong; Yao Li; Sun Jiashi; Zhang Jinsu [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Hua Ruinian [College of Life Science, Dalian Nationalities University, Dalian 116600 (China); Chen Baojiu, E-mail: chenmbj@sohu.com [Department of Physics, Dalian Maritime University, Dalian 116026 (China)

    2012-01-01

    Gd{sub 2}Mo{sub 3}O{sub 9} phosphors with various Dy{sup 3+} concentrations were synthesized by a traditional solid-state reaction using Na{sub 2}CO{sub 3} as a flux. The influence of reaction temperature and Dy{sup 3+}-doping concentration on the crystal structure of the phosphors was examined by XRD (X-ray diffraction). The effect of Dy{sup 3+}-doping concentration on the emissions of Mo-O bond and Dy{sup 3+} was experimentally investigated. The energy transfers between host and Dy{sup 3+} ions, and between Dy{sup 3+} ions were analyzed based on both the Van Uitert and I-H models. The chromatic properties of the phosphors were also discussed.

  10. Solid-state synthesis and electrochemical performance of Li4Ti5O12/graphene composite for lithium-ion batteries

    Highlights: • Homogeneous Li4Ti5O12/graphene composite is prepared via an in situ solid state reaction with the help of carbon pre-coating. • Carbon coating confines agglomeration of the Li4Ti5O12 particle and enhances the combination between Li4Ti5O12 particles and graphene sheets. • The homogeneous Li4Ti5O12/graphene composite delivers a quite high capacity of about 136 mAh g−1 at 120 C. -- Abstract: Homogeneous Li4Ti5O12/graphene composite is prepared via an in-situ solid state reaction, after carbon pre-coating has been carried out. Its microstructure is compared with the materials prepared by a similar way, but without carbon coating. The results reveal that the carbon coating not only effectively confines aggregation and agglomeration of the Li4Ti5O12 particles, but also enhances the combination between Li4Ti5O12 particles and graphene sheets. The Li4Ti5O12/graphene composite presents excellent rate capability and low-temperature performance. Even at 120 C, it still delivers a quite high capacity of about 136 mAh g−1. When the charge–discharge tests are performed at −10 °C and −20 °C, its specific capacities are as high as 149 and 102 mAh g−1, respectively. In addition, the full-cells using LiNi1/3Co1/3Mn1/3O2 as cathode material exhibit good rate capability

  11. Synthesis and electrochemical performance of 5V spinel LiNi0.5Mn1.5O4 prepared by solid-state reaction

    SUN Qiang; LI Xin-hai; WANG Zhi-xing; JI Yong

    2009-01-01

    Spinel compound LiNi0.5Mn1.5O4 with high capacity and high rate capability was synthesized by solid-state reaction. At first, MnCl2·4H2O and NiCl2·6H2O were reacted with (NH4)2C2O4·H2O to produce a precursor via a low-temperature solid-state route, then the precursor was reacted with Li2CO3 to synthesize LiNi0.5Mn1.5O4. The effects of calcination temperature and time on the physical properties and electrochemical performance of the products were investigated. Samples were characterized by thermal gravimetric analysis(TGA), scanning electron microscopy(SEM), X-ray diffractometry(XRD), charge-discharge tests and cyclic voltammetry measurements. Scanning electron microscopy(SEM) image shows that as calcination temperature and time increase, the crystallinity of the samples is improved, and their grain sizes are obviously increased. It is found that LiNi0.5Mn1.5O4 calcined at 800 ℃ for 6 h exhibits a typical cubic spinel structure with a space group of Fd3m. Electrochemical tests demonstrate that the sample obtained possesses high capacity and excellent rate capability. When being discharged at a rate as high as 5C after 30 cycles, the as-prepared LiNi0.5Mn1.5O4 powders can still deliver a capacity of 101 mA-h/g, which shows to be a potential cathode material for high power batteries.

  12. Forming-free, bi-directional polarity conductive-bridge memory devices with Ge2Sb2Te5 solid-state electrolyte and Ag active electrode

    Huang, Yin-Hsien; Chen, Hsuan-An; Wu, Hsin-Han; Hsieh, Tsung-Eong

    2015-01-01

    Preparation and characteristics of conductive-bridge random access memory devices containing Ge2Sb2Te5 (GST) chalcogenide as the solid-state electrolyte, Ag as the active electrode, and W-Ti as the counter electrode are presented. As revealed by the electrical measurement, only the samples containing crystalline GST exhibited the resistive switching behaviors. With an insertion of ZnS-SiO2 dielectric layer at the Ag/GST interface and a postannealing at 100 °C for 1 min, the sample exhibited the best electrical performance with satisfactory cycleability and retention properties. Moreover, the forming-free and bi-directional polarity features were observed in such a sample type. Microstructure and composition analyses found the finely dispersed nano-scale Ag clusters in GST and, when electrical bias is applied, the migrating Ag ions may build up the connections in between neighboring Ag clusters. Moreover, grain boundaries in polycrystalline GST might be the main paths for Ag migration. The thread-like conduction channels in GST hence form, leading to the low resistance state of sample. On the contrary, the depletion of Ag in GST broke the connections in between Ag clusters when the electrical bias is reversed. This led to the rupture of conduction channels and, hence, the high resistance state of sample. The low operational voltage, forming-free, and bi-directional polarity features observed in (AZGW)T sample might also originated from the fine dispersion of Ag clusters in GST electrolyte.

  13. Study of variations of radon emanations from soil in Morocco using solid state nuclear track detectors. Correlations with atmospheric parameters and seismic activities

    This study investigates the quantity variations of radon emanating from soil in accordance with time. It aims to verify the possibility of the radon sign use in earthquake prediction. Regular measures of radon concentration in soil have been carried out over the two years 1991 and 1992 in five towns of Morocco: Rabat, Tetouan, Ifrane and Khouribga, and in geophysic observatory of Ibn Rochd (Berchid region). The measuring method is based on the solid state nuclear track detectors technique. The obtained results have shown an influence of the atmospheric effects on the radon emanation. The experiment proved that, on one hand, the variations of the aforesaid influence are correlated to variations of the pluviometry and the atmospheric temperature and, on the other hand, there is no notable effect of atmospheric pressure or atmospheric humidity. The good correlations between the different seismic activities and the variations of radon emanation rate in the five measurement stations, have shown the interest of radon use in the earthquake prediction field. 81 refs., 100 figs., 17 tabs.(F. M.)

  14. Activities at the Institute of Materials and Solid State Research of the Karlsruhe Nuclear Research Centre in the field of fuel pin modelling

    Fuel pin modelling has been pursued at the Institute of Materials and Solid State Research (IMF) of the Karlsruhe Nuclear Research Centre (KfK) with the main objective to provide a detailed quantitative analysis of the fuel pin behaviour in a LMFBR under normal and off-normal operation conditions. The computer programs and models developed at the IMF serve the purpose to aid effectively in the development of an optimized fuel pin concept for a LMFBR. What extent of clad deformation can be tolerated without running into clad failure? What is the influence of neutron dose, temperature, corrosion attack, arid cyclic forces on the state of the clad? What may be the reasons for clad failure? In answering these questions computer programs can play an important role. The activities at the IMF in the field of fuel pin modelling cover the following topics: development of computer programs and models; validation of these programs and models, application to the design of fuel pins for irradiation experiments; assistance in the evaluation of operation data and post- irradiation results, and parametric studies on the influence of design parameters, operation conditions and certain material phenomena on the in-pile behaviour of the fuel pin

  15. Preparation, electronic structure, and photoluminescent properties of Eu2+ activated BaSi2O5 powder phosphors for solid-state lighting

    The green-emitting phosphor BaSi2O5:Eu2+ was synthesized by the conventional solid state reaction. Using the CASTEP code, BaSi2O5 is calculated to be an intermediate band gap semiconductor with an indirect energy gap of about 3. 2 eV. As expected, the calculated optical band gap of BaSi2O5 is lower compared to the experimentally determined values. Eu2+-activated BaSi2O5 phosphor can be excited efficiently over a broad spectral range between 200 and 400 nm, and has an emission peak at 500 nm with a full width at half maximum of 95 nm. The study of concentration-dependent emission intensity shows the optimal concentration of the Eu2+ is 0.05 mol, and that concentration quenching occurs when the Eu2+ content is beyond the critical value. The external quantum efficiency of the optimized BaSi2O5:Eu2+ is 96. 1%, 70. 2% and 62. 1% under excitation at 315, 350 and 365 nm, respectively. The superior optical properties of the sample show the potential as an ultraviolet converting green-emitting phosphor for white light emitting diodes. (paper)

  16. Phosphate phosphors for solid-state lighting

    Shinde, Kartik N. [N.S. Science and Arts College, Bhadrawati (India). Dept. of Physics; Swart, H.C. [University of the Orange Free State, Bloemfontein (South Africa). Dept. of Physics; Dhoble, S.J. [R.T.M. Nagpur Univ. (India). Dept. of Physics; Park, Kyeongsoon [Sejong Univ., Seoul (Korea, Republic of). Faculty of Nanotechnology and Advanced Materials Engineering

    2012-07-01

    Essential information for students in researchers working towards new and more efficient solid-state lighting. Comprehensive survey based on the authors' long experience. Useful both for teaching and reference. The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  17. Reaction kinetics for the solid state synthesis of the AlH3/MgCl2 nano-composite by mechanical milling.

    Duan, C W; Hu, L X; Sun, Y; Zhou, H P; Yu, H

    2015-09-14

    The process of mechanical milling has been proved to be a cost-effective way to synthesize the AlH3/MgCl2 nano-composite by using MgH2 and AlCl3 as reagents. However, so far there is no comprehensive knowledge of the kinetics of this process. In an effort to predict the reaction progress and optimize the milling parameters, the kinetics of the synthesis of the AlH3/MgCl2 nano-composite by mechanical milling of MgH2 and AlCl3 is experimentally investigated in the present work. The reaction progress or the transformation fraction upon milling for different times is evaluated using the isothermal hydrogen desorption test of the as-milled samples at 220 °C, which is much lower than the threshold temperature for the de-hydriding of the reagent MgH2 but enough for the de-hydriding of the as-synthesized nano-sized AlH3. The effects of milling parameters on the reaction kinetics as well as the underlying mechanism are discussed by referring to the mechanical energy input intensity, the vial temperature and the Gibbs free energy change for the reaction. Furthermore, it is found that the Johnson-Mehl-Avrami (JMA) model can well describe the kinetics theoretically. By fitting the experimental data with the JMA expression, the theoretical kinetics expressions, the equation parameters, and the activation energy are obtained. PMID:26256935

  18. Modern solid state laser materials

    This document contains visual aids used in an invited talk entitled Modern Solid State Laser Materials, presented at the Conference on Lasers and Electro-Optics (CLEO) held in Anaheim, California, on June 20, 1984. Interest at LLNL in solid state lasers focuses on evaluating the potential of solid state laser media for high average power applications, including inertial fusion power production. This talk identifies the relevant bulk material parameters characterizing average power capacity and uses chromium and neodymium co-doped gadolinium scandium gallium garnet (Nd:Cr:GSGG) as an example of a laser material with improved laser properties relative to Nd:YAG (plausible large-scale growth, more efficient spectral coupling to xenon flashlamp radiation, reduced stimulated emission cross section, adequate thermal shock and optical damage threshold parameters, etc.). Recently measured spectroscopic, kinetic, and thermo-mechanical properties of Nd:Cr:GSGG are given

  19. Solid state physics an introduction

    Hofmann, Philip

    2015-01-01

    A must-have textbook for any undergraduate studying solid state physics. This successful brief course in solid state physics is now in its second edition. The clear and concise introduction not only describes all the basic phenomena and concepts, but also such advanced issues as magnetism and superconductivity. Each section starts with a gentle introduction, covering basic principles, progressing to a more advanced level in order to present a comprehensive overview of the subject. The book is providing qualitative discussions that help undergraduates understand concepts even if they can?t foll

  20. Introduction to solid state electronics

    Wang, FFY

    1989-01-01

    This textbook is specifically tailored for undergraduate engineering courses offered in the junior year, providing a thorough understanding of solid state electronics without relying on the prerequisites of quantum mechanics. In contrast to most solid state electronics texts currently available, with their generalized treatments of the same topics, this is the first text to focus exclusively and in meaningful detail on introductory material. The original text has already been in use for 10 years. In this new edition, additional problems have been added at the end of most chapters. These proble

  1. Solid-state lithium battery

    Ihlefeld, Jon; Clem, Paul G; Edney, Cynthia; Ingersoll, David; Nagasubramanian, Ganesan; Fenton, Kyle Ross

    2014-11-04

    The present invention is directed to a higher power, thin film lithium-ion electrolyte on a metallic substrate, enabling mass-produced solid-state lithium batteries. High-temperature thermodynamic equilibrium processing enables co-firing of oxides and base metals, providing a means to integrate the crystalline, lithium-stable, fast lithium-ion conductor lanthanum lithium tantalate (La.sub.1/3-xLi.sub.3xTaO.sub.3) directly with a thin metal foil current collector appropriate for a lithium-free solid-state battery.

  2. Solid state physics for metallurgists

    Weiss, Richard J

    2013-01-01

    Metal Physics and Physical Metallurgy, Volume 6: Solid State Physics for Metallurgists provides an introduction to the basic understanding of the properties that make materials useful to mankind. This book discusses the electronic structure of matter, which is the domain of solid state physics.Organized into 12 chapters, this volume begins with an overview of the electronic structure of free atoms and the electronic structure of solids. This text then examines the basis of the Bloch theorem, which is the exact periodicity of the potential. Other chapters consider the fundamental assumption in

  3. Synthesis and properties of superconducting HgBa2CuO4+x from a single-step low-temperature solid state reaction

    A novel technique based on a low-temperature single-step solid state reaction of stoichiometric quantities of HgO and Ba2CuO3 to produce superconducting HgBa2CuO4+x samples has been developed. The 'as-prepared' polycrystalline Hg-1201 samples had a Tc of 95 K, as obtained by the diamagnetic onset and resistivity measurements. The crystal symmetry was tetragonal with lattice parameters a = 3.876(1) AA, and c = 9.509(4) AA in agreement with literature data. Sample morphology consists of grains (average dimension 30 μ m) larger than in previously published works and of a needle-like structure embedding the whole sample. These results were highly reproducible over several batches. The resistive transition in magnetic field up to 8 T and a set of magnetic measurements is presented. From these measurements we obtain information about the irreversibility line, the critical current field dependence and the presence of weak links. (author)

  4. Synthesis and Characterization of Ce-Doped Y3Al5O12 (YAG:Ce Nanopowders Used for Solid-State Lighting

    Do Ngoc Chung

    2014-01-01

    Full Text Available Nano-Ce-doped Y3Al5O12 (YAG:Ce powders were synthesized by using a sol-gel low temperature combustion method, followed by thermal annealing. The annealing temperature for enriching nanoparticles was optimized and found to be 1000°C. The process for enriching uniform nanoparticles of YAG:Ce powder was carried out by using the nanosteam technique (NST. The nanoparticles obtained from this NST treatment had a size in the range of 9–20 nm. Measurements of the photoluminescence spectra of the dispersed YAG:Ce nanoparticles solutions showed a blue shift in the photoemission with a value of ca. 10 nm in the green region. WLEDs made from the blue LED chip coated with the nano-YAG:Ce + MEH-PPV composite epoxy exhibit white light with a broad band luminescent spectrum and a high color rending index (CRI. The photoluminescence spectra of the YAG:Ce nanoparticles showed a potential application of the prepared nanostructured YAG:Ce phosphor not only in energy-efficient solid-state lighting, but also in optoelectronic devices, including organic composite solar cells. In addition, it is suggested that NST can be applied for the enrichment of uniform inorganic nanoparticles.

  5. Synthesis of Bi{sub 2}S{sub 3} with different sulfur content by conventional high temperature solid state solvothermal route

    Solanki, S. I., E-mail: patelishverb@yahoo.com; Patel, I. B., E-mail: patelishverb@yahoo.com [Department of Physics, Veer Narmad South Gujarat University, Surat-395007 (India); Shah, N. M. [Physics Department, A.N. Shah Science College, Kamrej-394185 (India)

    2014-04-24

    Bismuth sulfide (Bi{sub 2}S{sub 3}) is a binary chalcogenide compound material belonging to V-VI group of semiconductors. Because of its direct band gap of 1.3 eV and high figure of merit (ZT) value, it is widely used as a thermo electronic-cooling material based on the Peltier effect. The electrical and optical property of Bi{sub 2}S{sub 3} material is strongly dependent on stoichiometric composition, defect chemistry and structure. In this study, we have synthesized Bi{sub 2}S{sub x} (x = 3.15, 3.30, 3.45) compound material with different sulfur content by conventional high temperature solid state solvothermal reaction of bismuth and sulfur. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDXS) analysis of synthesized compound materials were carried out to observe crystallinity, surface morphology and composition of elements in the compound. The optical analysis revealed that energy band gap decreases with increase of sulfur content.

  6. Control of Solid-State Dye-Sensitized Solar Cell Performance by Block-Copolymer-Directed TiO2 Synthesis

    Docampo, Pablo

    2010-04-21

    Hybrid dye-sensitized solar cells are typically composed of mesoporous titania (TiO2), light-harvesting dyes, and organic molecular hole-transporters. Correctly matching the electronic properties of the materials is critical to ensure efficient device operation. In this study, TiO 2 is synthesized in a welldefined morphological confinement that arises from the self-assembly of a diblock copolymer - poly(isoprene-b-ethylene oxide) (Pl-b-PEO). The crystallization environment, tuned by the inorganic (TiO2 mass) to organic (polymer) ratio, is shown to be a decisive factor in determining the distribution of sub-bandgap electronic states and the associated electronic function in solid-state dye-sensitized solar cells. Interestingly, the tuning of the sub-bandgap states does not appear to strongly influence the charge transport and recombination in the devices. However, increasing the depth and breadth of the density of sub-bandgap states correlates well with an increase in photocurrent generation, suggesting that a high density of these sub-bandgap states is critical for efficient photo-induced electron transfer and charge separation. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Synthesis and characterisation of composite based biohydroxyapatite bovine bone mandible waste (BHAp) doped with 10 wt % amorphous SiO2 from rice husk by solid state reaction

    Asmi, Dwi; Sulaiman, Ahmad; Oktavia, Irene Lucky; Badaruddin, Muhammad; Zulfia, Anne

    2016-04-01

    Effect of 10 wt% amorphous SiO2 from rice husk addition on the microstructures of biohydroxyapatite (BHAp) obtained from bovine bone was synthesized by solid state reaction. In this study, biohydroxyapatite powder was obtained from bovine bone mandible waste heat treated at 800 °C for 5 h and amorphous SiO2 powder was extracted from citric acid leaching of rice husk followed by combustion at 700°C for 5 h. The composite powder then mixed and sintered at 1200 °C for 3 h. X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy and Scanning electron microscopy (SEM) techniques are utilized to characterize the phase relations, functional group present and morphology of the sample. The study has revealed that the processing procedures played an important role in microstructural development of BHAp-10 wt% SiO2 composite. The XRD study of the raw material revealed that the primary phase material in the heat treated of bovine bone mandible waste is hydroxyapatite and in the combustion of rice husk is amorphous SiO2. However, in the composite the hydroxyapatite, β-tricalcium phosphate, and calcium phosphate silicate were observed. The FTIR result show that the hydroxyl stretching band in the composite decrease compared with those of hydroxyapatite spectra and the evolution of morphology was occurred in the composite.

  8. Synthesis, structures of four coordination compounds constructed from o-methacrylamidobenzoic acid and their relationship between structure and solid state luminescence

    Four new coordination compounds, namely, Zn(o-MAABA)2(Phen) (1), [Cd(o-MAABA)2·2H2O]2 (2), ([Pb2Cl2(o-MAABA)2(Phen)4])·2H2O (3·2H2O), [Pb(NO3)(o-MAABA)(Phen)]n (4), where o-MAABA=o-methacrylamidobenzoic acid and phen=1, 10-phenanthroline, have been synthesized. All compounds were fully confirmed by FT-IR, elemental analysis and TGA analysis. Their structures were determined by single crystal X-ray diffraction, in which compound 1 shows a mononuclear structure, compounds 2 and 3 have binuclear structures and compound 4 shows an infinite chain. In 2 and 4, the adjacent chains are extended into a 3D supramolecular architecture via π–π interactions. Solid-state room temperature luminescence spectra revealed that emission bands of compound 1 were located at 524 nm (λex=352 nm) and compound 4 at 479 and 584 nm (λex=390 nm) assigned to the excimer formation. The emission at 454 nm (λex=340 nm) of compound 2 was mainly ascribed to the Ligand–Metal Charge Transfer (LMCT). - Graphical abstract: Four coordination compounds constructed by o-methacrylamidobenzoic, phenanthroline and metal ions are reported. The photoluminescent properties is studied, which is affected by the molecular stacking and LMCT.

  9. Solid-state mechanochemical synthesis of CsHSO4 and 1,2,4-triazole inorganic-organic composite electrolytes for dry fuel cells

    Inorganic-organic composite electrolytes for use in dry fuel cells were synthesized from CsHSO4 (CHS) and 1,2,4-triazole (Tz). CHS and Tz were mechanochemically treated in a dry nitrogen atmosphere to obtain composites with xCHS.(100 - x)Tz, where x is the amount (mol) and was varied in increments of 10 between 90 and 50. Structural investigation of the composites indicated that chemical interactions occurred between CHS and Tz after solid-state mechanochemical treatment. The proton conductivity of the composite electrolytes was largely increased by introduction of Tz, particularly in the low temperature region. The composite with x = 80 showed high proton conductivity (6.0 x 10-4 to 1.60 x 10-3 S cm-1) over a wide temperature range (60-160 oC) in a dry atmosphere. These observations suggest that proton transfer in the CHS and Tz composite systems includes the proton-hopping mechanism and self-dissociation. This phenomenon probably supports proton diffusion, especially in low temperature regions.

  10. A High Power Linear Solid State Pulser

    Particle Accelerators require high voltage and often high power. Typically the high voltage/power generation utilizes a topology with an extra energy store and a switching means to extract that stored energy. The switches may be active or passive devices. Active switches are hard or soft vacuum tubes, or semiconductors. When required voltages exceed tens of kilovolts, numerous semiconductors are stacked to withstand that potential. Such topologies can use large numbers of critical parts that, when in series, compromise the system reliability and performance. This paper describes a modular, linear, solid state amplifier which uses a parallel array of semiconductors, coupled with transmission line transformers. Such a design can provide output signals with voltages exceeding 10kV (into 50-ohms), and with rise and fall times (10-90 % amplitude) that are less than 1--ns. This compact solid state amplifier is modular, and has both hot-swap and soft fail capabilities

  11. Photoluminescence properties of sub-micron NaGd1-xEux(WO4)2 red phosphor for solid state lightings application: Derived by different synthesis routes

    Durairajan, A.; Suresh Kumar, J.; Thangaraju, D.; Valente, M. A.; Moorthy Babu, S.

    2016-05-01

    A series of NaGd1-xEux(WO4)2 (NGEW) red emitting phosphors were synthesized by three different methods, like conventional solid state reaction method, sol-gel and combustion reaction method. Detail investigations were made in terms of structural, vibrational, morphological, and luminescence analysis to identify changes with respect to three different synthesized methods. The formations of scheelite phase were confirmed by x-ray powder diffraction in all the three different synthesis methods and dopant ions do not alter its structure. Raman analysis indicated tetrahedral and translation motion tungstate assembly vibrations of synthesized NGEW samples. Morphology and grain size changes were observed in the SEM micrographs with respect to synthesis methods. The concentration dependent luminescence was studied and highest emission Eu3+ concentration in NGW matrix was found to be 60 mol% and critical distance was estimated by using Blasse approximation. The CIE co-ordinates of different methods derived NaGd0.40Eu0.60(WO4)2 were calculated and these values were fall in red region in CIE diagram and also well matched NTSC standard value. The Judd-Ofelt parameters (Ω2 and Ω4) were calculated by using emission spectra, to conform the occupancy and site symmetry of the Eu3+ ions in NGW matrix. The size control and luminescence ability suggested that the sol-gel method was significant method to synthesis red phosphor for using the red component in future lightings and display applications.

  12. Synthesis of an organic–inorganic hybrid material by solid state intercalation of 2-mercaptopyridine into Na-, Al(III)- and Co(II)-montmorillonite

    I Bekri-Abbes; E Srasra

    2006-06-01

    The preparation of an organic–inorganic hybrid material by solid state intercalation of 2-merca-ptopyridine (2Mpy) into Na-, Co(II)- and Al(III)-montmorillonite has been studied using a variety of techniques. The extension of 001 from XRD proves that the intercalation of 2-mercaptopyridine into Na-, Co(II)- and Al(III)-mont occurs at ambient temperature in 5 mn. When the intercalated samples were heated at different temperatures, we found that the 001 gave different values. For instance, for intercalated Al(III)- and Co(II)-, 001 remained unchanged for a temperature under 500°C. However, for intercalated Na-mont, it shifted to 14 Å for a temperature of 300°C, the washing of different samples with a methanol solution shifted the 001 of intercalated Na-mont to 14 Å. However, for intercalated Al(III) and Co(II), it did not change. This proves that in the case of Na-mont, the molecules of 2-mercaptopyridine interact with the clay through hydrogen bindings and physical interactions. However, for Al(III) and Co(II), it forms coordination linking and physical interaction. 13C NMR and FTIR spectroscopy have been employed for the characterization of the intercalation compounds. Tautomeric equilibrium between thiol and thione species of 2-mercaptopyridine must be taken into account to explain the arrangement of molecular aggregates and their particular orientation in the interlayer space. The isotherm of adsorption–desorption of nitrogen and topographic AFM images prove that intercalation of 2Mpy is accompanied by a total blockage of clay porosity and an increase in roughness.

  13. Ce11Ge3.73(2)In6.27: Solid-state synthesis, crystal structure and site-preference

    Jeon, Beom-Yong; Nam, Gnu; Lee, Dong Woo; Min Ok, Kang; You, Tae-Soo

    2016-04-01

    A novel intermetallic compound of Ce11Ge3.73(2)In6.27 has been synthesized through the high-temperature solid-state reaction using Nb-ampoules. A batch of well grown block-/short bar-shaped single-crystals has been obtained, and the crystal structure of the title compound has been characterized by single-crystal X-ray diffraction analyses. Ce11Ge3.73(2)In6.27 adopts the Ho11Ge10-type structure belonging to the tetragonal space group I4/mmm (Z=4, Pearson symbol tI84) with nine crystallographically unique atomic positions in the asymmetric unit. The lattice parameters are a=12.0163(1) Å and c=16.5396(2) Å. The overall crystal structure can simply be depicted as an assembly of three different types of co-facial cationic polyhedra centered by anions, which is further enclosed by the three-dimensional (3-D) cage-like anionic framework. The extra amount of In is observed in one of three isolated anionic sites resulting in introducing the Ge/In-mixed site at the Wyckoff 4e site. This unique site-preference of In substitution for Ge at the 4e site has been enlightened via the atomic size-aspect which was fully supported and rationalized by the site- and bond-energies analyses using tight-binding linear muffin-tin orbital (TB-LMTO) calculations. Energy-dispersive X-ray spectroscopy (EDS), density of states (DOS), crystal orbital Hamilton population (COHP), and electron localization function (ELF) analyses for the title compound are also presented. Magnetic susceptibility measurement proves that an antiferromagnetic ordering of Ce atoms at a low temperature with a paramagnetic Curie temperature of -23.2 K.

  14. A novel yellow-emitting SrAlSi4N7:Ce3+ phosphor for solid state lighting: Synthesis, electronic structure and photoluminescence properties

    Ce3+-doped and Ce3+/Li+-codoped SrAlSi4N7 phosphors were synthesized by gas pressure sintering of powder mixtures of Sr3N2, AlN, α-Si3N4, CeN and Li3N. The phase purity, electronic crystal structure, photoluminescence properties of SrAlSi4N7:Ce3+(Ce3+/Li+) were investigated in this work. The band structure calculated by the DMol3 code shows that SrAlSi4N7 has a direct band gap of 3.87 eV. The single crystal analysis of Ce3+-doped SrAlSi4N7 indicates a disordered Si/Al distribution and nitrogen vacnacy defects. SrAlSi4N7 was identified as a major phase of the fired powders, and Sr5Al5Si21N35O2 and AlN as minor phases. Both Ce3+ and Ce3+/Li+ doped SrAlSi4N7 phosphors can be efficiently excited by near-UV or blue light and show a broadband yellow emission peaking around 565 nm. A highest external quantum efficiency of 38.3% under the 450 nm excitation was observed for the Ce3+/Li+-doped SrAlSi4N7 (5 mol%). A white light LED lamp with color temperature of 6300 K and color rendering index of Ra=78 was achieved by combining Sr0.97Al1.03Si3.997N/94/maccounttest14=t000518193 7:Ce3+0.03 with a commercial blue InGaN chip. It indicates that SrAlSi4N7:Ce3+ is a promising yellow emitting down-conversion phosphor for white LEDs. - Graphical abstract: One-phosphor converted white light-emitting diode (LED) was fabricated by combining a blue LED chip and a yellow-emitting SrAlSi4N7:Ce3+ phosphor (see inset), which has the color rendering index of 78 and color temperature of 6300 K. - Highlights: • We reported a new yellow nitride phosphor suitable for solid state lighting. • We solved the crystal structure and evidenced a disordered Si/Al distribution. • We fabricated a high color rendering white LEDs by using a single SrAlSi4N7:Ce

  15. Study of the influence of the soil and plant natures and pollution on the radon and thoron alpha activities inside various herbal infusions by using solid state nuclear track detectors

    Different medicinal plant, spinach and cereal samples have been analysed by using neutron activation analysis and radiochemical separation. The solid state nuclear track detectors technique was utilized for uranium and thorium contents determination as well as for alpha, beta, and gamma dose rates evaluation in various geological and ceramic samples. In this study, uranium and thorium contents have been determined in different plant samples, soils in which they have been grown and in herbal infusions made by boiling the studied plants in potable water by using CR-39 and LR-115 solid state nuclear track detectors. Radon and thoron alpha activities per unit volume inside the plants, soils and herbal infusions studied have been evaluated. The radon transfers between soils and plants as well as between plants and herbal infusions have been investigated. The influence of pollution due to different material dusts on radon and thoron alpha activities inside the plants and their corresponding infusions has been studied. (author)

  16. Advances in Solid State Physics

    Haug, Rolf

    2007-01-01

    The present volume 46 of Advances in Solid State Physics contains the written versions of selected invited lectures from the spring meeting of the Arbeitskreis Festkörperphysik of the Deutsche Physikalische Gesellschaft which was held from 27 to 31 March 2006 in Dresden, Germany. Many topical talks given at the numerous symposia are included. Most of these were organized collaboratively by several of the divisions of the Arbeitskreis. The topis range from zero-dimensional physics in quantum dots, molecules and nanoparticles over one-dimensional physics in nanowires and 1d systems to more applied subjects like optoelectronics and materials science in thin films. The contributions span the whole width of solid-state physics from truly basic science to applications.

  17. Solid-state membrane module

    Gordon, John Howard; Taylor, Dale M.

    2011-06-07

    Solid-state membrane modules comprising at least one membrane unit, where the membrane unit has a dense mixed conducting oxide layer, and at least one conduit or manifold wherein the conduit or manifold comprises a dense layer and at least one of a porous layer and a slotted layer contiguous with the dense layer. The solid-state membrane modules may be used to carry out a variety of processes including the separating of any ionizable component from a feedstream wherein such ionizable component is capable of being transported through a dense mixed conducting oxide layer of the membrane units making up the membrane modules. For ease of construction, the membrane units may be planar.

  18. Solid-state laser engineering

    Koechner, Walter

    1992-01-01

    This book is written from an industrial perspective and provides a detailed discussion of solid-state lasers, their characteristics, design and construction. Emphasis is placed on engineering and practical considerations. The book is aimed mainly at the practicing scientist or engineer who is interested in the design or use of solid-state lasers, but the comprehensive treatment of the subject will make the work useful also to students of laser physics who seek to supplement their theoretical knowledge with engineering information. In order to present the subject as clearly as possible, phenomenological descriptions using models have been used rather than abstract mathematical descriptions. This results in a simplified presentation. The descriptions are enhanced by the inclusion of numerical and technical data, tables and graphs. This new edition has been updated and revised to take account of important new developments, concepts, and technologies that have emerged since the publication of the first and second...

  19. Solid state physics at ISOLDE

    Deicher, M; Wichert, T

    2003-01-01

    Radioactive atoms have been used in solid state physics and in materials science for decades. Besides their classical applications as tracers for diffusion studies, nuclear techniques such as Mossbauer spectroscopy, perturbed gamma gamma angular correlation, beta -NMR, and emission channeling make use of nuclear properties (via hyperfine interactions or emitted alpha or beta particles) to gain microscopic information on structural and dynamical properties of solids. During the last decade, the availability of many different radioactive isotopes as clean ion beams at ISOL facilities like ISOLDE/CERN has triggered a new era involving methods sensitive to the optical and electronic properties of solids, especially in the field of semiconductor physics. This overview will browse through ongoing solid state physics experiments with radioactive ion beams at ISOLDE. A wide variety of problems is under study, involving bulk properties, surfaces and interfaces in many different systems like semiconductors, superconduc...

  20. Modeling solid-state precipitation

    Nebylov, AlexanderKozeschnik, Ernst

    2012-01-01

    Over recent decades, modeling and simulation of solid-state precipitation has attracted increased attention in academia and industry due to their important contributions in designing properties of advanced structural materials and in increasing productivity and decreasing costs for expensive alloying. In particular, precipitation of second phases is an important means for controlling the mechanical-technological properties of structural materials. However, profound physical modeling of precipitation is not a trivial task. This book introduces you to the classical methods of precipitation model

  1. Solid-State Nuclear Power

    George, Jeffrey A.

    2012-01-01

    A strategy for "Solid-State" Nuclear Power is proposed to guide development of technologies and systems into the second 50 years of nuclear spaceflight. The strategy emphasizes a simple and highly integrated system architecture with few moving parts or fluid loops; the leverage of modern advances in materials, manufacturing, semiconductors, microelectromechanical and nanotechnology devices; and the targeted advancement of high temperature nuclear fuels, materials and static power conversion to enable high performance from simple system topologies.

  2. Division of solid state physics

    This report gives a survey of the present research projects at the division of solid state physics, Inst. of Technology, Uppsala University. The projects fall within the fields of magnetism, i.e. spin glasses, ordered magnetic structures and itinerant electron magnetism, and optics, i.e. properties of crystalline and amorphous materials for selective transmission and absorption in connection with energy-related research. (author)

  3. Introduction to solid state physics

    A compact introduction to solid-state physics for students of physics, material,and engineering sciences - ideal for a one- to two-semestral course. In easily understable form the author introduces to phenomena and concepts. Thereby he avoids expensive mathematical derivations and refers to outgoing literature. The successful didactical preparation makes an easy access to the theme possible. Numerous illustrations clarify the connections and make the explained well understandable. With about 170 questions and exercise problems.

  4. Improvement of Medium Chain Fatty Acid Content and Antimicrobial Activity of Coconut Oil via Solid-State Fermentation Using a Malaysian Geotrichum candidum

    Anahita Khoramnia; Afshin Ebrahimpour; Raheleh Ghanbari; Zahra Ajdari; Oi-Ming Lai

    2013-01-01

    Coconut oil is a rich source of beneficial medium chain fatty acids (MCFAs) particularly lauric acid. In this study, the oil was modified into a value-added product using direct modification of substrate through fermentation (DIMOSFER) method. A coconut-based and coconut-oil-added solid-state cultivation using a Malaysian lipolytic Geotrichum candidum was used to convert the coconut oil into MCFAs-rich oil. Chemical characteristics of the modified coconut oils (MCOs) considering total medium ...

  5. Two dimensional solid state NMR

    This thesis illustrates, by discussing some existing and newly developed 2D solid state experiments, that two-dimensional NMR of solids is a useful and important extension of NMR techniques. Chapter 1 gives an overview of spin interactions and averaging techniques important in solid state NMR. As 2D NMR is already an established technique in solutions, only the basics of two dimensional NMR are presented in chapter 2, with an emphasis on the aspects important for solid spectra. The following chapters discuss the theoretical background and applications of specific 2D solid state experiments. An application of 2D-J resolved NMR, analogous to J-resolved spectroscopy in solutions, to natural rubber is given in chapter 3. In chapter 4 the anisotropic chemical shift is mapped out against the heteronuclear dipolar interaction to obtain information about the orientation of the shielding tensor in poly-(oxymethylene). Chapter 5 concentrates on the study of super-slow molecular motions in polymers using a variant of the 2D exchange experiment developed by us. Finally chapter 6 discusses a new experiment, 2D nutation NMR, which makes it possible to study the quadrupole interaction of half-integer spins. 230 refs.; 48 figs.; 8 tabs

  6. Advances in Solid State Physics

    Haug, Rolf

    2008-01-01

    The present volume 47 of the Advances in Solid State Physics contains the written version of a large number of the invited talks of the 2007 Spring Meeting of the Arbeitskreis Festkörperphysik which was held in Regensburg, Germany, from March 26 to 30, 2007 in conjunction with the 71st Annual Meeting of the Deutsche Physikalische Gesellschaft.It gives an overview of the present status of solid state physics where low-dimensional systems such as quantum dots and quantum wires are dominating. The importance of magnetic materials is reflected by the large number of contributions in the part dealing with ferromagnetic films and particles. One of the most exciting achievements of the last couple of years is the successful application of electrical contacts to and the investigation of single layers of graphene. This exciting physics is covered in Part IV of this book. Terahertz physics is another rapidly moving field which is presented here by five contributions. Achievements in solid state physics are only rarely...

  7. Kinetic Role of Carbon in Solid-State Synthesis of Zirconium Diboride using Nanolaminates: Nanocalorimetry Experiments and First-Principles Calculations.

    Lee, Dongwoo; Sim, Gi-dong; Zhao, Kejie; Vlassak, Joost J

    2015-12-01

    Reactive nanolaminates afford a promising route for the low-temperature synthesis of zirconium diboride, an ultrahigh-temperature ceramic with metallic properties. Although the addition of carbon is known to facilitate sintering of ZrB2, its effect on the kinetics of the formation reaction has not been elucidated. We have employed a combined approach of nanocalorimetry and first-principles theoretical studies to investigate the kinetic role of carbon in the synthesis of ZrB2 using B4C/Zr reactive nanolaminates. Structural characterization of the laminates by XRD and TEM reveal that the reaction proceeds via interdiffusion of the B4C and Zr layers, which produces an amorphous Zr3B4C alloy. This amorphous alloy then crystallizes to form a supersaturated ZrB2(C) compound. A kinetic analysis shows that carbon lowers the energy barriers for both interdiffusion and crystallization by more than 20%. Energetic calculations based on first-principles modeling suggest that the reduction of the diffusion barrier may be attributed to the stronger bonding between Zr and C as compared to the bonding between Zr and B. PMID:26536309

  8. Sol-gel chemistry applied to the synthesis of polymetallic oxides including actinides reactivity and structure from solution to solid state

    Minor actinides transmutation is studied at present in order to reduce the radiotoxicity of nuclear waste and the assessment of its technical feasibility requires specific designed materials. When considering americium, yttria stabilized zirconia (AmIII YII Zriv)Orx is among the ceramic phases that one which presents the required physico-chemical properties. An innovative synthesis of this mixed oxide by sol-gel process is reported in this manuscript. The main aim of this work is to adjust the reactivity of the different metallic cations in aqueous media using complexing agent, in order to initiate a favourable interaction for a homogeneous elements repartition in the forming solid phase. The originality of the settled synthesis lies on an in-situ formation of a stable and monodisperse nano-particles dispersion in the presence of acetylacetone. The main reaction mechanisms have been identified: the sol stabilisation results from an original interaction between the three compounds (Zrly, trivalent cations and acetylacetone). The sol corresponds to a structured system at the nanometer scale for which zirconium and trivalent cations are homogeneously dispersed, preliminary to the sol-gel transition. Furthermore, preliminary studies were carried out with a view to developing materials. They have demonstrated that numerous innovative and potential applications can be developed by taking advantage of the direct and controlled formation of the sol and by adapting the sol-gel transition. The most illustrating result is the preparation of a sintered pellet with the composition Am0,13Zro,73Yo,0901,89 using this approach. (author)

  9. Hyperbranched polymers from polymerization in solid state

    The macroscopic properties of polymers are directly related to the chemical characteristics of the monomeric units and also with the geometric arrangement of polymer chains. Thus, polymers were synthesized from two well-known chelators EDTA and EDA. We evaluated the conditions for the polymerization of the precursors in the solid state. The polymerization was carried out varying the proportions of reagents, aiming the polymers with different degrees of chain branching and the materials were characterized by FTIR. The materials obtained from the best condition for synthesis were purified by size-exclusion chromatography of and were subjected to characterization by FTIR and NMR of 1H and 13C. The content of end groups in these samples was determined by back titration. (author)

  10. Sol-Gel chemistry applied to the synthesis of Am-bearing cubic stabilised zirconia: reactivity and structure from solution to solid state

    Full text of publication follows. In the frame of the transmutation of minor actinides, recent concepts of nuclear targets imply the elaboration of inert host phases. Wet chemical routes are under investigations for their synthesis as alternative ways to the powder metallurgy. The main advantages of these methods are a minimization of the dissemination of contaminating dusts when elaborating nuclear materials and a better accessibility to very homogenous compounds and interesting nano-structures. Among these routes, an innovative synthesis by sol-gel process is reported here to synthesize yttria-stabilised zirconia, an inert ceramic phase candidate for the transmutation of americium: (AmIII,YIII,ZrIV)O2-x. Starting from an initial solution containing Zr(IV), Y(III) and Am(III) [or Nd(III)], the main aim of this work is to adjust the reactivity of different metallic cations in aqueous media using a complexing agent, in order to initiate a favourable interaction for the repartition of homogeneous elements in the forming solid phase. Investigations on several complexing agents to control the reactivity of these cations with a view to making them react simultaneously have been performed. Among them, the use of acetylacetone led to the formation of a stable and monodisperse nano-particle dispersion under controlled conditions. The main reaction mechanisms implied in the sol formation were identified using different techniques: IR and UV-visible spectroscopies, quasi-elastic light scattering, electrokinetic measurements and potentiometric studies. The sol stabilisation may result from an original interaction between the three compounds (ZrIV, trivalent cations and acetylacetone): hydrous zirconia nano particles (homogenous in size and around 5 nm) are formed and stabilised by surface complexation with acac and trivalent cations. This sol corresponds to a structured system at the nanometer scale for which zirconium and trivalent cations are homogeneously dispersed, before

  11. New materials for solid state electrochemistry

    Solid state electrochemistry is an interdisciplinary area, undergoing nowadays a fast development. It is related on the one hand to chemistry, and on the other hand to crystallography, solid state physics and materials science. In this paper structural and electrical properties of some families of new materials interesting for solid state electrochemistry are reviewed. Attention is focused essentially on ceramic and crystalline materials, glasses and polymers, displaying high ionic conductivity and potentially suitable for various applications in solid state electrochemical devices. (orig.)

  12. The Oxford solid state basics

    Simon, Steven H

    2013-01-01

    The study of solids is one of the richest, most exciting, and most successful branches of physics. While the subject of solid state physics is often viewed as dry and tedious this new book presents the topic instead as an exciting exposition of fundamental principles and great intellectual breakthroughs. Beginning with a discussion of how the study of heat capacity of solids ushered in the quantum revolution, the author presents the key ideas of the field while emphasizing the deepunderlying concepts. The book begins with a discussion of the Einstein/Debye model of specific heat, and the Drude

  13. Solar pumped solid state lasers

    Results are presented for direct solar pumping of a Nd:YAG rod laser. Stable CW output of more than 60 watts was obtained with slope efficiencies exceeding 2%. Results are consistent with predictions based on a simple solar laser model the authors have developed. Using this model, performance projections and design concepts for higher power and higher efficiency solar-pumped solid state lasers are presented. It is shown that existing laser materials with broadband absorption characteristics (e.g., alexandrite and Nd:Cr:GSGG) can have better than 10% overall conversion efficiencies when solar pumped. The utility of solar lasers for various laser applications in space is briefly discussed

  14. Solid State Theory An Introduction

    Rössler, Ulrich

    2009-01-01

    Solid-State Theory - An Introduction is a textbook for graduate students of physics and material sciences. It stands in the tradition of older textbooks on this subject but takes up new developments in theoretical concepts and materials which are connected with such path breaking discoveries as the Quantum-Hall Effects, the high-Tc superconductors, and the low-dimensional systems realized in solids. Thus besides providing the fundamental concepts to describe the physics of electrons and ions of which the solid consists, including their interactions and the interaction with light, the book casts a bridge to the experimental facts and opens the view into current research fields.

  15. Production, characterization and anticancer activity of Candida bombicola sophorolipids by means of solid state fermentation of sunflower oil cake and soybean oil

    Rashad, M. M.; Nooman, M. U.; Ali, M M; Al-kashef, A. S.; Mahmoud, A E

    2014-01-01

    The production of sophorolipids by Candida bombicola NRRL Y- 17069 grown in a mixture of sunflower oil cake and crude soybean oil as economic substrates with different fermentation techniques was studied. The highest yield (49.5 g·100 g−1 substrates) was obtained from solid state fermentation after employing a new concept for extraction by methanol (E I) followed by ethyl acetate (E II), then partially purified with hexane (E III). The course of time of fermentation was also studied, and E I ...

  16. Production, characterization and anticancer activity of Candida bombicola sophorolipids by means of solid state fermentation of sunflower oil cake and soybean oil

    Rashad, M. M.

    2014-06-01

    Full Text Available The production of sophorolipids by Candida bombicola NRRL Y- 17069 grown in a mixture of sunflower oil cake and crude soybean oil as economic substrates with different fermentation techniques was studied. The highest yield (49.5 g·100 g−1 substrates was obtained from solid state fermentation after employing a new concept for extraction by methanol (E I followed by ethyl acetate (E II, then partially purified with hexane (E III. The course of time of fermentation was also studied, and E I extracted of the 12th day showed the minimum surface tension (45 mN·m−1 at a critical micelle dilution (CMD of 10% concentration. The produced sophorolipids were characterized and confirmed by FTIR and 1H NMR spectroscopy. The anticancer activity of the produced compounds was assessed against MCF-7, HepG2, A549, HCT116 cancer cell lines and the results revealed that E III and E IV (a mixture of E I & E III act as promising anticancer agents in HepG2 and A549 by inhibiting urokinase and histone deacetylase activities.Se estudió la producción de soforolípidos por Candida bombicola NRRL Y- 17069 cultiva con diferentes técnicas de fermentación en una mezcla de torta de girasol y aceite de soja crudo, como sustratos económicos. El rendimiento más alto (49,5 g·100 g−1 de sustrato se obtuvo por fermentación en estado sólido después de extraer con metanol (IE seguido de acetato de etilo (EII, y de purificación parcial con hexano (EIII. También se estudió el tiempo de fermentación, considerando que el extracto IE de 12 días mostró una tensión superficial mínima (45 mN·m−1 a una dilución micelar crítica (CMD de concentración 10 %. Los soforolípidos producidos se caracterizaron y se confirmaron mediante espectroscopia FTIR y RMN de 1H. La actividad anticancerígena de los compuestos producidos se evaluó en células MCF-7, HepG2, A549, líneas celulares de cáncer de HCT116 y los resultados revelaron que EIII y EIV (una mezcla de EI y EIII

  17. Synthesis,Characterization and Thermodynamic Study of the Solid State Coordination Compound Ni(Nic)2·H2O(s)(Nic=Nicotinate)

    CHEN Jingtao; HE Donghua; DI Youying; KONG Yuxia; YANG Weiwei; DAN Wenyan; TAN Zhicheng

    2009-01-01

    A novel compound-monohydrated nickel nicotinate was synthesized by the method of room temperature solid phase synthesis and ball grinder.FT1R,chemical and elemental analysis,TG/DTG,and X-ray powder diffraction technique were applied to characterize the structure and composition of the coordination compound.Low-temperature heat capacities of the solid coordination compound have been measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 386 K.A solid-solid phase transition occurred in the temperature range of 328-358 K in the heat capacity curve,and the peak temperature,the molar enthalpy and moties in the temperature ranges of 78-328 K and 358-386 K were fitted to two polynomials,respectively.The polynomial fitted values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were calculated and tabulated at the intervals of 5 K.

  18. Solid-state array cameras.

    Strull, G; List, W F; Irwin, E L; Farnsworth, D L

    1972-05-01

    Over the past few years there has been growing interest shown in the rapidly maturing technology of totally solid-state imaging. This paper presents a synopsis of developments made in this field at the Westinghouse ATL facilities with emphasis on row-column organized monolithic arrays of diffused junction phototransistors. The complete processing sequence applicable to the fabrication of modern highdensity arrays is described from wafer ingot preparation to final sensor testing. Special steps found necessary for high yield processing, such as surface etching prior to both sawing and lapping, are discussed along with the rationale behind their adoption. Camera systems built around matrix array photosensors are presented in a historical time-wise progression beginning with the first 50 x 50 element converter developed in 1965 and running through the most recent 400 x 500 element system delivered in 1972. The freedom of mechanical architecture made available to system designers by solid-state array cameras is noted from the description of a bare-chip packaged cubic inch camera. Hybrid scan systems employing one-dimensional line arrays are cited, and the basic tradeoffs to their use are listed. PMID:20119094

  19. IGBT: A solid state switch

    A Copper Vapor Laser Power Supply has been designed using a solid state switch consisting in eighteen Isolated Gate Bipolar Transistors (IGBT), 1,200 volts, 400 Amps, each, in parallel. This paper presents the Isolated Gate Bipolar Transistor (IGBTs) replaced in the Power Electronic components evolution, and describes the IGBT conduction mechanism, presents the parallel association of IGBTs, and studies the application of these components to a Copper Vapor Laser Power Supply. The storage capacitor voltage is 820 Volts, the peak current of the solid state switch is 17,000 Amps. The switch is connected on the primary of a step-up transformer, followed by a magnetic modulator. The reset of the magnetic modulator is provided by part of the laser reflected energy with a patented circuit. The charging circuit is a resonant circuit with a charge controlled by an IGBT switch. When the switch is open, the inductance energy is free-wheeled by an additional winding and does not extend the charging phase of the storage capacitor. The design allows the storage capacitor voltage to be very well regulated. This circuit is also patented. The electric pulse in the laser has 30,000 Volt peak voltage, 2,000 Amp peak current, and is 200 nanoseconds long, for a 200 Watt optical power Copper Vapor Laser

  20. Contamination and solid state welds.

    Mills, Bernice E.

    2007-05-01

    Since sensitivity to contamination is one of the verities of solid state joining, there is a need for assessing contamination of the part(s) to be joined, preferably nondestructively while it can be remedied. As the surfaces that are joined in pinch welds are inaccessible and thus provide a greater challenge, most of the discussion is of the search for the origin and effect of contamination on pinch welding and ways to detect and mitigate it. An example of contamination and the investigation and remediation of such a system is presented. Suggestions are made for techniques for nondestructive evaluation of contamination of surfaces for other solid state welds as well as for pinch welds. Surfaces that have good visual access are amenable to inspection by diffuse reflection infrared Fourier transform (DRIFT) spectroscopy. Although other techniques are useful for specific classes of contaminants (such as hydrocarbons), DRIFT can be used most classes of contaminants. Surfaces such as the interior of open tubes or stems that are to be pinch welded can be inspected using infrared reflection spectroscopy. It must be demonstrated whether or not this tool can detect graphite based contamination, which has been seen in stems. For tubes with one closed end, the technique that should be investigated is emission infrared spectroscopy.

  1. IGBT: a solid state switch

    A Copper Vapour Laser Power Supply has been designed using a solid state switch consisting in eighteen Isolated Gate Bipolar Transistors (IGBT), -1200 volts, 400 Amps, each-in parallel. This paper presents the Isolated Gate Bipolar Transistor (IGBTs) replaced in the Power Electronic components evolution, and describes the IGBT conduction mechanism, presents the parallel association of IGBTs, and studies the application of these components to a Copper Vapour Laser Power Supply. The storage capacitor voltage is 820 volts, the peak current of the solid state switch is 17.000 Amps. The switch is connected on the primary of a step-up transformer, followed by a magnetic modulator. The reset of the magnetic modulator is provided by part of the laser reflected energy with a patented circuit. The charging circuit is a resonant circuit with a charge controlled by an IGBT switch. When the switch is open, the inductance energy is free-wheeled by an additional winding and does not extend the charging phase of the storage capacitor. The design allows the storage capacitor voltage to be very well regulated. This circuit is also patented. The electric pulse in the laser has 30.000 Volt peak voltage, 2000 Amp peak current, and is 200 nanoseconds long, for a 200 Watt optical power Copper Vapour Laser

  2. Advances in Solid State Physics

    Haug, Rolf

    2009-01-01

    The present volume 48 of the Advances in Solid State Physics contains the written version of a large number of the invited talks of the 2008 Spring Meeting of the DPG section Condensed Matter Physics (Sektion kondensierte Materie der DPG) which was held in Berlin, Germany, and gives a nice overview of the present status of condensed matter physics. Low-dimensional systems are dominating the field and especially nanowires and quantum dots. In recent years one learned how to produce nanowires directly during a growth process. Therefore, a number of articles is related to such nanowires. In nanoparticles and quantum dots, the dimensionality is further reduced and we learn more and more how to produce such systems in a defined way and what effects result from the confinement in all three dimensions. Spin effects and magnetism is another important field of present-day research in solid state physics. The third chapter covers this physics. The growing interest into organic materials and biological systems is reflec...

  3. Solid State Lighting Program (Falcon)

    Meeks, Steven

    2012-06-30

    Over the past two years, KLA-Tencor and partners successfully developed and deployed software and hardware tools that increase product yield for High Brightness LED (HBLED) manufacturing and reduce product development and factory ramp times. This report summarizes our development effort and details of how the results of the Solid State Light Program (Falcon) have started to help HBLED manufacturers optimize process control by enabling them to flag and correct identified killer defect conditions at any point of origin in the process manufacturing flow. This constitutes a quantum leap in yield management over current practice. Current practice consists of die dispositioning which is just rejection of bad die at end of process based upon probe tests, loosely assisted by optical in-line monitoring for gross process deficiencies. For the first time, and as a result of our Solid State Lighting Program, our LED manufacturing partners have obtained the software and hardware tools that optimize individual process steps to control killer defects at the point in the processes where they originate. Products developed during our two year program enable optimized inspection strategies for many product lines to minimize cost and maximize yield. The Solid State Lighting Program was structured in three phases: i) the development of advanced imaging modes that achieve clear separation between LED defect types, improves signal to noise and scan rates, and minimizes nuisance defects for both front end and back end inspection tools, ii) the creation of defect source analysis (DSA) software that connect the defect maps from back-end and front-end HBLED manufacturing tools to permit the automatic overlay and traceability of defects between tools and process steps, suppress nuisance defects, and identify the origin of killer defects with process step and conditions, and iii) working with partners (Philips Lumileds) on product wafers, obtain a detailed statistical correlation of automated

  4. Solid State Division: Progress report for period ending September 30, 1987

    This paper contains a collection of articles on research done at the Solid State Division of ORNL. General topics covered are: theoretical solid state physics; neutron scattering; physical properties of superconductors and ceramics; synthesis and characterization of solids; ion beam and laser processing; and surface and defect studies

  5. Combinatorial nano chemical technology and solid state physics. Innovation in oxide and organic electronics research

    Solid state physics is based on well-defined materials made by the sophisticated chemical synthesis. Emerging combinatorial chemical technology is coupled with nano-technology to facilitate breakthroughs in solid state physics by speeding up the screening of materials. Examples are presented from oxide crystals and organic molecules for electronics. (author)

  6. Solid State Division: Progress report for period ending September 30, 1987

    Green, P.H.; Watson, D.M. (eds.)

    1988-03-01

    This paper contains a collection of articles on research done at the Solid State Division of ORNL. General topics covered are: theoretical solid state physics; neutron scattering; physical properties of superconductors and ceramics; synthesis and characterization of solids; ion beam and laser processing; and surface and defect studies. (LSP)

  7. Solid state synthesis and sintering of monazite-type ceramics: application to minor actinides conditioning; Synthese par voie solide et frittage de ceramiques a structure monazite. Application au conditionnement des actinides mineurs

    Bregiroux, D

    2005-11-15

    In the framework of the French law of 1991 concerning the nuclear waste management, several studies are undertaken to develop specific crystalline conditioning matrices. Monazite, a rare earth (TR{sup 3+}) orthophosphate with a general formula TR{sup 3+}PO{sub 4}, is a natural mineral containing significant amount of thorium and uranium. Monazite has been proposed as a host matrix for the minor actinides (Np, Am and Cm) specific conditioning, thanks to its high resistance to self irradiation and its low solubility. Its is now of prime importance to check the conservation of these properties on synthesized materials, which implies to master all the stages of the elaboration process, from the powder synthesis to the sintering of controlled microstructure pellets. This work can be divided into two main parts: The first part deals with the synthesis by high temperature solid state route of TR{sup 3+}PO{sub 4} powders (with TR{sup 3+} = La{sup 3+} to Gd{sup 3+}, Pu{sup 3+} and Am{sup 3+}). The chemical reactions occurring during the firing of starting reagents are described in the case of monazite with only one or several cations. From these results, a protocol of synthesis is described. The incorporation of tetravalent cations (Ce{sup 4+}, U{sup 4+}, Pu{sup 4+}) in the monazite structure was also studied. The second part of the present work deals with the elaboration of controlled density and microstructure monazite pellets and their related mechanical and thermal properties. The study of crushing and sintering is presented. For the first time, experimental results are confronted with theoretical models in order to deduce the densification and grain growth mechanisms. By the comprehension of the various physicochemical phenomena occurring during the various stages of the monazite pellets elaboration process (powder synthesis, crushing, sintering...), this work allowed the development of a protocol of elaboration of controlled microstructure monazite TR{sup 3+}PO{sub 4

  8. Synthesis and crystal structure of new temephos analogues as cholinesterase inhibitor: molecular docking, QSAR study, and hydrogen bonding analysis of solid state.

    Gholivand, Khodayar; Ebrahimi Valmoozi, Ali Asghar; Bonsaii, Mahyar

    2014-06-25

    A series of temephos (Tem) derivatives were synthesized and characterized by 31P, 13C, and 1H NMR and FT-IR spectral techniques. Also, the crystal structure of compound 9 was investigated. The hydrogen bonding energies (E2) were calculated by NBO analysis of the crystal cluster. The activities and the mixed-type mechanism of Tem derivatives were evaluated using the modified Ellman's and Lineweaver-Burk's methods on cholinesterase (ChE) enzymes. The inhibitory activities of Tem derivatives with a P═S moiety were higher than those with a P═O moiety. Docking analysis disclosed that the hydrogen bonds occurred between the OR (R=CH3 and C2H5) oxygen and N-H nitrogen atoms of the selected compounds and the receptor site (GLN and GLU) of ChEs. PCA-QSAR indicated that the correlation coefficients of the electronic variables were dominant compared to the structural descriptors. MLR-QSAR models clarified that the net charges of nitrogen and phosphorus atoms contribute important electronic function in the inhibition of ChEs. The validity of the QSAR model was confirmed by a LOO cross-validation method with q2=0.965 between the training and testing sets. PMID:24893121

  9. Synthesis of PVA-Chitosan Hydrogels for Wound Dressing Using Gamma Irradiation. Part I: Radiation Degradation of Chitosan in Solid State and in Solution

    Chitosan is a partially deacetylated product of chitin, a very abundant polysaccharide, existing in exoskeleton of crustaceans. It is a polymer consisting of glucosamine and N-acetylglucosamine units linked by β-1-4-glycosidic bonds. Chitosan, like others polysaccharides, such as cellulose derivatives, alginates and carrageenan is widely used in food, medicine and cosmetic fields. Chitosan presents a variety of distinctive properties, such as biocompatibility, biodegradability, nontoxicity and nonantigenicity. Chitosan obtained by the deacetylation of chitin has, generally, a high molecular weight, which limits its solubility in aqueous solvents. The reduction of its molecular weight by degradation is usually used in order to improve its water solubility. Water-soluble chitosan exhibit some specific properties, such as antifungal activity, antimicrobial activity and plant growth promotion. Among the methods that have been tried to produce low molecular weight chitosan, radiation processing is the most promising one, since the process is simple, it is carried out at room temperature and no purification of the product is required after processing

  10. Solid-State Random Lasers

    Noginov, Mikhail A

    2005-01-01

    Random lasers are the simplest sources of stimulated emission without cavity, with the feedback provided by scattering in a gain medium. First proposed in the late 60’s, random lasers have grown to a large research field. This book reviews the history and the state of the art of random lasers, provides an outline of the basic models describing their behavior, and describes the recent advances in the field. The major focus of the book is on solid-state random lasers. However, it also briefly describes random lasers based on liquid dyes with scatterers. The chapters of the book are almost independent of each other. So, the scientists or engineers interested in any particular aspect of random lasers can read directly the relevant section. Researchers entering the field of random lasers will find in the book an overview of the field of study. Scientists working in the field can use the book as a reference source.