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Haitao Wang - One of the best experts on this subject based on the ideXlab platform.
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ultrafast discharge and high energy density of polymer nanocomposites achieved via optimizing the structure design of Barium Titanates
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Zhongbin Pan, Lingmin Yao, Jiwei Zhai, Ke Yang, Bo Shen, Haitao WangAbstract:Electrostatic capacitors have been applied into high-power-density pulsed power systems comprising moderate energy density and ultrafast charging/discharging in the order of magnitude with a few milliseconds. In this article, different BaTiO3 nanostructures (e.g., nanoparticles, nanofibers, nanotubes, core–shell structure nanofibers) were synthesized and used to prepare polymer composite films in the poly(vinylidene fluoride) (PVDF) matrix. The effects of BaTiO3 nanostructures on the dielectric constant, dielectric loss, alternating current conductivity, breakdown strength, energy density, and mechanical properties of nanocomposites were investigated systematically. The largest dielectric constant of 17.14 was found in the 4 vol % BaTiO3 nanotube/PVDF nanocomposites. The BaTiO3@Al2O3 nanofiber/PVDF nanocomposites show the highest energy density of 12.37 J cm–3 at 450 MV m–1, ultrafast discharge speed (0.32 μs), and good mechanical properties. This article could open up a convenient and effective way for p...
Roger H Mitchell - One of the best experts on this subject based on the ideXlab platform.
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rare earth element bearing tausonite and potassium Barium Titanates from the little murun potassic alkaline complex yakutia russia
Mineralogical Magazine, 1993Co-Authors: Roger H MitchellAbstract:Tausonites occurring in aegirine potassium feldspar syenite from the Little Murun potassic alkaline complex are characterised by complex growth and resorption features. These are attributed to non-equilibrium crystallisation in a dynamic environment characterised by magma mixing and/or volatile degassing. The crystals represent a transported assemblage which has no simple relationship to the magma from which their host rock crystallised. Tausonites exhibit significant normal, reverse and oscillatory compositional zoning with respect to strontium and the rare earth elements. The compositions are unique, ranging from tausonite to strontian cerian loparite, and are unlike those found in strontian perovskites from lamproites and fenites associated with carbonatites
Min Che Chon - One of the best experts on this subject based on the ideXlab platform.
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controlled double jet precipitation of uniform colloidal crystalline particles of zr and sr doped Barium Titanates
Journal of Materials Research, 1996Co-Authors: Yieshein Her, Egon Matijevic, Min Che ChonAbstract:The synthesis of uniform colloidal crystalline particles of Zr- and Sr-doped Barium Titanates at a low temperature of 85 °C by the controlled double-jet precipitation (CDJP) technique is described. The stoichiometry of the powders can be precisely controlled by adjusting the compositions of the starting reactant solutions. Barium titanate with 20% Zr substitution, sintered at 1275 °C, satisfied the requirements for the Y5V multilayer capacitors application. The grain sizes are uniform and small, ranging from 1 to 3 μm. Solids with an extremely sharp change in the dielectric constant as a function of temperature, which are suitable for thermal IR detectors application, can be obtained when both Sr and Zr are incorporated as dopants.
Hansjoachim Kleebe - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of mixed valence Barium Titanates
Philosophical Magazine, 2003Co-Authors: Thomas Hoche, Ralf Keding, Christian Russel, Hansjoachim Kleebe, Paula Olhe, Peter A Van Aken, Reinhard Schneider, Xiqu Wang, Allan J Jacobson, Susanne StemmerAbstract:A single-crystal Barium oxotitanate(III, IV) of approximate composition Ba5:93(Ti 3þ 11:86Ti 4þ 28:14ÞO80, containing mixed-valence Ti, was grown from a borate flux. The crystal structure was identified as hollandite type by single-crystal X-ray diffractometry. Electron-energy-loss spectroscopy of Ti L2;3 and O K edges was used to determine chemical shifts related to the presence of mixed-valence Ti in the crystal. Comparison of Ti L2;3 and O K energy-loss near-edge structure
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oxidation states of titanium in bulk Barium Titanates and in 100 fiber textured baxsr1 x ti1 yo3 z thin films
Applied Physics Letters, 2001Co-Authors: Susanne Stemmer, Thomas Hoche, Ralf Keding, Christian Russel, R Schneider, Nigel D Browning, S K Streiffer, Hansjoachim KleebeAbstract:Chemical shifts of titanium L edges and oxygen K edges in electron energy-loss spectroscopy in transmission electron microscopy were used to detect valence state reduction of Ti in bulk Barium Titanates, used as reference materials, and in (BaxSr1−x)Ti1+yO3+z (BST) thin films grown with excess Ti. A hollandite-type Ba titanate, containing Ti with an average valence state of approximately 3.7 in octahedral coordination, showed large chemical shifts relative to rutile TiO2 and BaTiO3, containing only Ti4+. In BST, chemical shifts relative to BaTiO3 were measured from grain interiors of columnar films with different amounts of excess Ti. We found that shifts, corresponding to an average valence state of Ti smaller than nominal 4+, increase with increasing amounts of excess Ti in the films. The results show that at least some amount of excess Ti is accommodated in these films by a defect mechanism that requires a reduction of the average valence state of Ti.
Zhongbin Pan - One of the best experts on this subject based on the ideXlab platform.
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ultrafast discharge and high energy density of polymer nanocomposites achieved via optimizing the structure design of Barium Titanates
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Zhongbin Pan, Lingmin Yao, Jiwei Zhai, Ke Yang, Bo Shen, Haitao WangAbstract:Electrostatic capacitors have been applied into high-power-density pulsed power systems comprising moderate energy density and ultrafast charging/discharging in the order of magnitude with a few milliseconds. In this article, different BaTiO3 nanostructures (e.g., nanoparticles, nanofibers, nanotubes, core–shell structure nanofibers) were synthesized and used to prepare polymer composite films in the poly(vinylidene fluoride) (PVDF) matrix. The effects of BaTiO3 nanostructures on the dielectric constant, dielectric loss, alternating current conductivity, breakdown strength, energy density, and mechanical properties of nanocomposites were investigated systematically. The largest dielectric constant of 17.14 was found in the 4 vol % BaTiO3 nanotube/PVDF nanocomposites. The BaTiO3@Al2O3 nanofiber/PVDF nanocomposites show the highest energy density of 12.37 J cm–3 at 450 MV m–1, ultrafast discharge speed (0.32 μs), and good mechanical properties. This article could open up a convenient and effective way for p...