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Masaru Miyayama - One of the best experts on this subject based on the ideXlab platform.

  • crystal growth and characterization of bi0 5na0 5 tio3 batio3 single crystals obtained by the top seeded solution growth method under High Pressure Oxygen atmosphere
    Key Engineering Materials, 2013
    Co-Authors: Hiroaki Onozuka, Yuuki Kitanaka, Yuji Noguchi, Masaru Miyayama
    Abstract:

    A single crystal of ferroelectric 0.88(Bi,Na)TiO30.12BaTiO3 (BNTBT) solid solution with tetragonal P4mm structure was grown by the top-seeded solution growth (TSSG) method at a High Oxygen Pressure (PO2) of 0.9 MPa. The crystals grown by the High-PO2 TSSG method exhibited a large remanent polarization (Pr) of 54 μC/cm2, which leads to a spontaneous polarization of 54 μC/cm2. The large Pr compared with that of crystals grown at PO2 = 0.1 MPa is suggested to originate from a low Oxygen vacancy concentration for the crystals grown at a Higher PO2. The High-PO2 TSSG method was demonstrated to be effective for obtaining BNTBT crystals with superior polarization and piezoelectric properties.

  • crystal growth and characterization of bi _ 0 5 na _ 0 5 tio _ 3 batio _ 3 single crystals obtained by a top seeded solution growth method under High Pressure Oxygen atmosphere
    Japanese Journal of Applied Physics, 2011
    Co-Authors: Hiroaki Onozuka, Yuuki Kitanaka, Yuji Noguchi, Masaru Miyayama
    Abstract:

    A single crystal of ferroelectric 0.88(Bi,Na)TiO3–0.12BaTiO3 (BNT–BT) solid solution with tetragonal P4mm structure was grown by a top-seeded solution growth (TSSG) method at a High Oxygen Pressure (PO2 ) of 0.9 MPa. The crystals exhibited a large remanent polarization (Pr) of 54 µC/cm2, which leads to a spontaneous polarization estimated to be 54 µC/cm2. The large Pr compared with that of crystals grown at PO2 = 0.1 MPa is suggested to originate from a low Oxygen vacancy concentration. The High-PO2 TSSG method is demonstrated to be effective for obtaining large-sized, High-quality BNT–BT crystals.

  • High performance bi0 5na0 5tio3 single crystals grown by High Oxygen Pressure flux method
    Japanese Journal of Applied Physics, 2008
    Co-Authors: Katsuya Yamamoto, Muneyasu Suzuki, Yuji Noguchi, Masaru Miyayama
    Abstract:

    High-PO2 (Oxygen Pressure) crystal growth is developed for Bi0.5Na0.5TiO3 single crystals based on defect chemistry at High temperatures. Thermogravimetric analysis shows that the vacancy formations of Bi and O at High temperatures are controlled by the surface reaction (Oxygen desorption), which is suppressed at a Higher PO2 . Bi0.5Na0.5TiO3 crystals grown at a PO2 of 1 MPa exhibit a saturated remanent polarization of 44 µC/cm2 along [110]cubic, suggesting a spontaneous polarization of 54 µC/cm2 along [111]cubic (polar direction) of rhombohedral Bi0.5Na0.5TiO3. High-PO2 heat treatments are proposed to be effective for fabricating High-quality and High-performance ferroelectric/piezoelectric devices using Bi-based ferroelectric oxides.

  • High Oxygen Pressure crystal growth of ferroelectric bi4ti3o12 single crystals
    Applied Physics Letters, 2007
    Co-Authors: Katsuya Yamamoto, Yuuki Kitanaka, Muneyasu Suzuki, Masaru Miyayama, Yuji Noguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa
    Abstract:

    We have investigated the effects of High-Oxygen-Pressure crystal growth of ferroelectric Bi4Ti3O12 on the polarization properties along the a(b) axis. Domain observations by piezoresponse force microscope demonstrate that a small remanent polarization (Pr) for the crystals grown at 0.02MPa is attributed to the clamping of 90° domain walls by Oxygen vacancies. The vacancy formation of Bi and O during crystal growth at High temperatures is suppressed at a Higher Oxygen Pressure, leading to a larger Pr of 47μC∕cm2 for the crystals grown at 1MPa Oxygen. High-Oxygen-Pressure sintering is proposed to be effective for obtaining Bi4Ti3O12-based devices with enhanced polarization properties.

Yuji Noguchi - One of the best experts on this subject based on the ideXlab platform.

  • crystal growth and characterization of bi0 5na0 5 tio3 batio3 single crystals obtained by the top seeded solution growth method under High Pressure Oxygen atmosphere
    Key Engineering Materials, 2013
    Co-Authors: Hiroaki Onozuka, Yuuki Kitanaka, Yuji Noguchi, Masaru Miyayama
    Abstract:

    A single crystal of ferroelectric 0.88(Bi,Na)TiO30.12BaTiO3 (BNTBT) solid solution with tetragonal P4mm structure was grown by the top-seeded solution growth (TSSG) method at a High Oxygen Pressure (PO2) of 0.9 MPa. The crystals grown by the High-PO2 TSSG method exhibited a large remanent polarization (Pr) of 54 μC/cm2, which leads to a spontaneous polarization of 54 μC/cm2. The large Pr compared with that of crystals grown at PO2 = 0.1 MPa is suggested to originate from a low Oxygen vacancy concentration for the crystals grown at a Higher PO2. The High-PO2 TSSG method was demonstrated to be effective for obtaining BNTBT crystals with superior polarization and piezoelectric properties.

  • crystal growth and characterization of bi _ 0 5 na _ 0 5 tio _ 3 batio _ 3 single crystals obtained by a top seeded solution growth method under High Pressure Oxygen atmosphere
    Japanese Journal of Applied Physics, 2011
    Co-Authors: Hiroaki Onozuka, Yuuki Kitanaka, Yuji Noguchi, Masaru Miyayama
    Abstract:

    A single crystal of ferroelectric 0.88(Bi,Na)TiO3–0.12BaTiO3 (BNT–BT) solid solution with tetragonal P4mm structure was grown by a top-seeded solution growth (TSSG) method at a High Oxygen Pressure (PO2 ) of 0.9 MPa. The crystals exhibited a large remanent polarization (Pr) of 54 µC/cm2, which leads to a spontaneous polarization estimated to be 54 µC/cm2. The large Pr compared with that of crystals grown at PO2 = 0.1 MPa is suggested to originate from a low Oxygen vacancy concentration. The High-PO2 TSSG method is demonstrated to be effective for obtaining large-sized, High-quality BNT–BT crystals.

  • High performance bi0 5na0 5tio3 single crystals grown by High Oxygen Pressure flux method
    Japanese Journal of Applied Physics, 2008
    Co-Authors: Katsuya Yamamoto, Muneyasu Suzuki, Yuji Noguchi, Masaru Miyayama
    Abstract:

    High-PO2 (Oxygen Pressure) crystal growth is developed for Bi0.5Na0.5TiO3 single crystals based on defect chemistry at High temperatures. Thermogravimetric analysis shows that the vacancy formations of Bi and O at High temperatures are controlled by the surface reaction (Oxygen desorption), which is suppressed at a Higher PO2 . Bi0.5Na0.5TiO3 crystals grown at a PO2 of 1 MPa exhibit a saturated remanent polarization of 44 µC/cm2 along [110]cubic, suggesting a spontaneous polarization of 54 µC/cm2 along [111]cubic (polar direction) of rhombohedral Bi0.5Na0.5TiO3. High-PO2 heat treatments are proposed to be effective for fabricating High-quality and High-performance ferroelectric/piezoelectric devices using Bi-based ferroelectric oxides.

  • High Oxygen Pressure crystal growth of ferroelectric bi4ti3o12 single crystals
    Applied Physics Letters, 2007
    Co-Authors: Katsuya Yamamoto, Yuuki Kitanaka, Muneyasu Suzuki, Masaru Miyayama, Yuji Noguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa
    Abstract:

    We have investigated the effects of High-Oxygen-Pressure crystal growth of ferroelectric Bi4Ti3O12 on the polarization properties along the a(b) axis. Domain observations by piezoresponse force microscope demonstrate that a small remanent polarization (Pr) for the crystals grown at 0.02MPa is attributed to the clamping of 90° domain walls by Oxygen vacancies. The vacancy formation of Bi and O during crystal growth at High temperatures is suppressed at a Higher Oxygen Pressure, leading to a larger Pr of 47μC∕cm2 for the crystals grown at 1MPa Oxygen. High-Oxygen-Pressure sintering is proposed to be effective for obtaining Bi4Ti3O12-based devices with enhanced polarization properties.

Yuuki Kitanaka - One of the best experts on this subject based on the ideXlab platform.

  • crystal growth and characterization of bi0 5na0 5 tio3 batio3 single crystals obtained by the top seeded solution growth method under High Pressure Oxygen atmosphere
    Key Engineering Materials, 2013
    Co-Authors: Hiroaki Onozuka, Yuuki Kitanaka, Yuji Noguchi, Masaru Miyayama
    Abstract:

    A single crystal of ferroelectric 0.88(Bi,Na)TiO30.12BaTiO3 (BNTBT) solid solution with tetragonal P4mm structure was grown by the top-seeded solution growth (TSSG) method at a High Oxygen Pressure (PO2) of 0.9 MPa. The crystals grown by the High-PO2 TSSG method exhibited a large remanent polarization (Pr) of 54 μC/cm2, which leads to a spontaneous polarization of 54 μC/cm2. The large Pr compared with that of crystals grown at PO2 = 0.1 MPa is suggested to originate from a low Oxygen vacancy concentration for the crystals grown at a Higher PO2. The High-PO2 TSSG method was demonstrated to be effective for obtaining BNTBT crystals with superior polarization and piezoelectric properties.

  • crystal growth and characterization of bi _ 0 5 na _ 0 5 tio _ 3 batio _ 3 single crystals obtained by a top seeded solution growth method under High Pressure Oxygen atmosphere
    Japanese Journal of Applied Physics, 2011
    Co-Authors: Hiroaki Onozuka, Yuuki Kitanaka, Yuji Noguchi, Masaru Miyayama
    Abstract:

    A single crystal of ferroelectric 0.88(Bi,Na)TiO3–0.12BaTiO3 (BNT–BT) solid solution with tetragonal P4mm structure was grown by a top-seeded solution growth (TSSG) method at a High Oxygen Pressure (PO2 ) of 0.9 MPa. The crystals exhibited a large remanent polarization (Pr) of 54 µC/cm2, which leads to a spontaneous polarization estimated to be 54 µC/cm2. The large Pr compared with that of crystals grown at PO2 = 0.1 MPa is suggested to originate from a low Oxygen vacancy concentration. The High-PO2 TSSG method is demonstrated to be effective for obtaining large-sized, High-quality BNT–BT crystals.

  • High Oxygen Pressure crystal growth of ferroelectric bi4ti3o12 single crystals
    Applied Physics Letters, 2007
    Co-Authors: Katsuya Yamamoto, Yuuki Kitanaka, Muneyasu Suzuki, Masaru Miyayama, Yuji Noguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa
    Abstract:

    We have investigated the effects of High-Oxygen-Pressure crystal growth of ferroelectric Bi4Ti3O12 on the polarization properties along the a(b) axis. Domain observations by piezoresponse force microscope demonstrate that a small remanent polarization (Pr) for the crystals grown at 0.02MPa is attributed to the clamping of 90° domain walls by Oxygen vacancies. The vacancy formation of Bi and O during crystal growth at High temperatures is suppressed at a Higher Oxygen Pressure, leading to a larger Pr of 47μC∕cm2 for the crystals grown at 1MPa Oxygen. High-Oxygen-Pressure sintering is proposed to be effective for obtaining Bi4Ti3O12-based devices with enhanced polarization properties.

Bruce E Rittmann - One of the best experts on this subject based on the ideXlab platform.

  • performance of a sulfide oxidizing sulfur producing membrane biofilm reactor treating sulfide containing bioreactor effluent
    Environmental Science & Technology, 2011
    Co-Authors: Erkan Sahinkaya, Anna H Kaksonen, Halil Hasar, Bruce E Rittmann
    Abstract:

    Sulfide-containing waste streams are generated in mining, petrochemical plants, tanneries, viscose rayon manufacture, and the gasification of coal. Colorless sulfur bacteria can oxidize sulfide to elemental sulfur (S°), which can be recovered, when Oxygen is their electron acceptor. This study evaluated sulfide oxidation and S° recovery in an Oxygen-based membrane biofilm reactor (MBfR) treating the effluent from a sulfidogenic anaerobic baffled reactor. Sulfide oxidation efficiency (37−99%) and S° recovery (64−89% of oxidized sulfide) could be controlled by manipulating the sulfide loading, Oxygen Pressure to the fibers, and hydraulic retention time (HRT). For example, too-low Oxygen Pressure decreased S° recovery due to decreased sulfide oxidation, but too-High Oxygen Pressure lowered S° recovery due to its oxidation to sulfate. Most importantly, High sulfide oxidation (>98%) and conversion to S° (>75%) could be achieved together when the sulfide loading was less than 1.7 mol/m2·d and the O2 Pressure wa...

  • performance of a sulfide oxidizing sulfur producing membrane biofilm reactor treating sulfide containing bioreactor effluent
    Environmental Science & Technology, 2011
    Co-Authors: Erkan Sahinkaya, Anna H Kaksonen, Halil Hasar, Bruce E Rittmann
    Abstract:

    Sulfide-containing waste streams are generated in mining, petrochemical plants, tanneries, viscose rayon manufacture, and the gasification of coal. Colorless sulfur bacteria can oxidize sulfide to elemental sulfur (S°), which can be recovered, when Oxygen is their electron acceptor. This study evaluated sulfide oxidation and S° recovery in an Oxygen-based membrane biofilm reactor (MBfR) treating the effluent from a sulfidogenic anaerobic baffled reactor. Sulfide oxidation efficiency (37-99%) and S° recovery (64-89% of oxidized sulfide) could be controlled by manipulating the sulfide loading, Oxygen Pressure to the fibers, and hydraulic retention time (HRT). For example, too-low Oxygen Pressure decreased S° recovery due to decreased sulfide oxidation, but too-High Oxygen Pressure lowered S° recovery due to its oxidation to sulfate. Most importantly, High sulfide oxidation (>98%) and conversion to S° (>75%) could be achieved together when the sulfide loading was less than 1.7 mol/m²·d and the O₂ Pressure was sufficient to give an O₂ flux of at least 1.5 mol/m²·d. However, Higher sulfide loading could be compensated by a Higher O₂ Pressure, and the best performance occurred when the sulfide loading was High (2 molS/m²·d), the O₂ Pressure was High (∼1 atm), and the HRT was short (1.9 h). Membrane fouling caused a low O₂ flux, which led to low sulfide-oxidation efficiency, but fouling could be reversed by mild acid washing.

B Dabrowski - One of the best experts on this subject based on the ideXlab platform.

  • crystal structure and magnetic properties of High Oxygen Pressure annealed sr1 xlaxco0 5fe0 5o3 δ 0 x 0 5
    Journal of Solid State Chemistry, 2009
    Co-Authors: Konrad świerczek, B Dabrowski, Leopoldo Suescun, S Kolesnik
    Abstract:

    Abstract Structural and magnetic studies are presented for the perovskite type Sr1−xLaxCo0.5Fe0.5O3−δ (0⩽x⩽0.5) materials annealed under moderately High-Oxygen Pressures of ∼200 atm. A detailed analysis of the room temperature neutron time-of-flight diffraction data reveals that the crystal structure of the sample SrCo0.5Fe0.5O2.89(1), previously described as vacancy-disordered cubic, is similar to the formerly reported, Oxygen-vacancy ordered Sr8Fe8O23 compound, i.e. Sr8Co4Fe4O23 is tetragonal with the I4/mmm symmetry. With an increase of the La content the studied materials become nearly Oxygen stoichiometric and a lowering of the crystal symmetry is observed from cubic Pm 3 ¯ m (x=0.1 and 0.2) to tetragonal I4/mcm (x=0.3 and 0.4), and finally to monoclinic I12/c1 (x=0.5). Low-temperature structural and magnetic measurements show a ferromagnetic ordering with the maximum Curie temperature near 290 K at x=0.2.

  • transition from curie weiss to enhanced pauli paramagnetism inrnio3 r la pr gd
    Physical Review B, 2003
    Co-Authors: J S Zhou, J B Goodenough, B Dabrowski
    Abstract:

    High-Oxygen-Pressure annealing, cold pressing, and measurement of properties under Pressure have been used to reveal and to follow in the single-valent perovskites RNiO 3 (R = lanthanide) a crossover from localized to itinerant electronic behavior. Cold pressing proved critical for obtaining nearly intrinsic transport properties such as electronic and thermal conductivity in polycrystalline samples not available as single crystals. Suppression of the thermal conductivity in the crossover compositions NdNiO 3 and PrNiO 3 suggests cooperative bond-length fluctuations in this region.