A5040142125- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Ferroelectric and Piezoelectric Materials
- Layered Double Hydroxides Synthesis and Applications
- Microwave Dielectric Ceramics Synthesis
- Luminescence Properties of Advanced Materials
- Rare-earth and actinide compounds
- Multiferroics and related materials
- Physics of Superconductivity and Magnetism
- Inorganic Chemistry and Materials
- Heusler alloys: electronic and magnetic properties
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Nuclear materials and radiation effects
- Advancements in Semiconductor Devices and Circuit Design
- MXene and MAX Phase Materials
- Low-power high-performance VLSI design
- Crystal Structures and Properties
- Magnetic Properties of Alloys
- Perovskite Materials and Applications
- 2D Materials and Applications
- Semiconductor Quantum Structures and Devices
- Magnetic properties of thin films
- Graphene research and applications
Jichi Medical University
2022-2024
National Institute for Materials Science
2007-2017
MegaChips (United States)
2017
Japan Science and Technology Agency
2009-2014
Centre de Recherche en Économie et Statistique
2014
Centre for Research in Engineering Surface Technology
2014
Center for Responsible Travel
2014
Aoyama Gakuin University
2003-2009
Kobe University
2009
University of Tsukuba
2008
We report the direct observation of dioxygen molecules physisorbed in nanochannels a microporous copper coordination polymer by MEM (maximum entropy method)/Rietveld method, using situ high-resolution synchrotron x-ray powder diffraction measurements. The obtained electron density revealed that van der Waals dimers O2 locate middle and form one-dimensional ladder structure aligned to host channel structure. observed O-O stretching Raman band magnetic susceptibilities are characteristic...
Combining different materials into desired superlattice structures can produce new electronic states at the interface and opportunity to create artificial with novel properties. Here we introduce a new, rather unexpected, yet simple way such assembly of perovskite oxides: in Dion−Jacobson phase, model system layered perovskites, high-quality bicolor superlattices (LaNb2O7)nL(Ca2Nb3O10)nC are successfully fabricated by layer-by-layer using two nanosheets (LaNb2O7 Ca2Nb3O10) as building block....
Caught on film: A semitransparent and intensely luminescent monolayer film of oriented Gd(2)O(3):0.05 Eu platelet crystallites is fabricated by annealing the precursor hydroxide (see scheme). The photoluminescence properties as-transformed are greatly improved over those film, much more pronounced than corresponding powder.
Eu3+-doped perovskite nanosheets, La0.90Eu0.05Nb2O7, have been prepared by the soft chemical exfoliation reaction of K1−xHxLa0.90Eu0.05Nb2O7 with a tetrabuthylammonium hydroxide aqueous solution. The resulting colloidal La0.90Eu0.05Nb2O7 nanosheet suspension exhibits photoluminescence emission from 5D0 to 7FJ manifold transitions Eu3+ either direct excitation or host excitation, whereas no was observed at room temperature. In case bulk precursors K1−xHxLa0.90Eu0.05Nb2O7, yields more intense...
Luminescent lanthanide hydroxide nanosheets: Dodecyl sulfate intercalated layered Eu was exfoliated in formamide to produce unilamellar nanosheets, which exhibited characteristic Eu3+ emission. These nanosheets are promising for a range of applications including ultrathin optical film devices.
The surface charge of various anionic unilamellar nanosheets, such as graphene oxide (GO), Ti0.87O2(0.52-), and Ca2Nb3O10(-) has been successfully modified to be positive by interaction with polycations while maintaining a monodispersed state. A dilute nanosheet suspension was slowly added dropwise into an aqueous solution high molecular weight polycations, which attach on the nanosheets via electrostatic interaction. Surface modification transformation positively charged were confirmed...
Layered rare-earth hydroxide crystallites self-assembled at the hexane/water interface were transferred to various substrates form a monolayer film, which exhibited photoluminescence properties and ion-exchange ability.
The synthesis of a series new layered rare-earth hydroxide solid solutions and their transformation into (EuxGd1−x)2O3 crystallites are described. Highly crystalline platelets EuxGd1−x(OH)2.5Cl0.5·0.9H2O with various Eu3+/Gd3+ ratios were prepared through homogeneous precipitation method. solid-solution samples exhibited characteristic Eu3+ photoluminescence properties the energy transfer from Gd3+ to self-excitation Eu3+. Cubic obtained via quasi-topotactic above 800 °C. as-transformed...
ADVERTISEMENT RETURN TO ISSUECommunicationNEXTRbBiNb2O7: A New Lead-Free High-Tc FerroelectricBao-Wen Li†, Minoru Osada*†‡, Tadashi C. Ozawa†‡, and Takayoshi Sasaki†‡View Author Information† International Center for Materials Nanoarchitectonics, National Institute Science, Tsukuba, Ibaraki, 305-0044, Japan‡ CREST, Japan Science Technology Agency, Kawaguchi, Saitama 332-0012, Japan*Fax: +81-29-854-9061. E-mail: [email protected]Cite this: Chem. Mater. 2012, 24, 16, 3111–3113Publication Date...
One of the basic requirements for attaining a good epitaxy is close structural matching between substrate and growing crystal epilayer. This restrictive requirement causes major obstacle its wide application to range functional films in electronic, magnetic or optical devices. approach overcoming this problem so-called van der Waals (VDWE) method, which can effectively implement various crystals on cleaved faces layered materials having no dangling bonds. The weak adatom–substrate...
The results of thermodynamic, transport, and x-ray diffraction measurements single crystals the new compound Yb14ZnSb11 are presented. These data indicate an intermediate Yb valence scenario, with a spin fluctuation temperature approximately 85 K. is weakly metallic isostructural charge-balanced Zintl Yb14AlSb11. can be qualitatively accounted for by considering charge counting arguments nonmetallic parent, balance in Zintl-related materials appears to viable route designing other compounds...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSoft-Chemical Exfoliation of Na0.9Mo2O4: Preparation and Electrical Conductivity Characterization a Molybdenum Oxide NanosheetDae Sung Kim*†‡, Tadashi C. Ozawa*†, Katsutoshi Fukuda§, Satoshi Ohshima⊥, Izumi Nakai⊥, Takayoshi Sasaki†View Author Information† International Center for Materials Nanoarchitectonics (MANA), National Institute Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan‡ Eco-Composite Center, Green Ceramics Division,...
A 1-Mb (256 K*4) CMOS SRAM with 6-ns access time is described. The SRAM, having a cell size of 3.8 mu m*7.2 m and die 6.09 mm*12.94 mm, fabricated by using 0.5- triple-polysilicon double-metal process technology. fast low power dissipation 52 mA at 100-MHz operation are achieved new NMOS source-controlled latched sense amplifier data-output prereset circuit. In addition, an equalizing technique the end write used to avoid lengthening in read cycle following cycle.< <ETX...
High photoactivator concentration nanosheets Eu0.56Ta2O7 have been prepared by the soft chemical exfoliation reaction of layered perovskite Li2-xHxEu0.56Ta2O7 with a tetrabutylammonium hydroxide aqueous solution. In-plane X-ray diffraction and TEM AFM observation results indicate that nanosheet is crystalline retains structural feature bulk precursors. The most intense emission observed from 5D0 → 7F2 transition Eu3+. intensity this host excitation exceeds 18 times direct Eu3+ excitation.
Platelet crystals of a layered perovskite enormously swelled in tetrabutylammonium hydroxide solution, producing unique columnar shaped with water content >90 wt%.
Eu3+-activated double perovskite-type nanosheet phosphor (K1.5Eu0.5)Ta3O10 has been prepared by the soft chemical exfoliation reaction of K(K1.5Eu0.5)Ta3O10 bulk precursor. The lateral size product ranges from 0.1 to a few micrometers, and thickness is uniformly 2.4(2) nm. lattice parameter along sheet direction obtained in-plane X-ray diffraction 0.3933(3) nm, corresponding typical O−Ta−O distances. photoluminescence emission can be either host or direct photoactivator excitation, but...
The compounds Na2Ti2Pn2O (Pn = As, Sb) crystallize in the anti-K2NiF4 structure type space group, I4/mmm, with Z 2 and lattice parameters a 4.0810(9) Å c 15.311(3) for As analogue at 310 K 4.160(2) 16.558(7) Sb 150 K. consists of edge-shared [Ti4/2Pn2O4/4]2- layers separated by double Na+. These exhibit an anomalous transition temperature-dependent magnetic susceptibility 330 120 analogue. Temperature-dependent powder neutron diffraction has been performed to investigate spin ordering...
The dielectric properties of KCa2Nan−3NbnO3n+1 (n=3–6) Dion–Jacobson homologous series have been investigated. constants (ε) increase with the number octahedral units (n), and n=6 compound (KCa2Na3Nb6O19) exhibits a stable response ε=∼500 between 1 kHz MHz. This n-dependent behavior is similar to those observed in other layered perovskites such as Ruddlesden–Popper Aurivillius phases. Raman scattering studies reveal that n leads higher polarizability lattice softening lowest-frequency phonon...
An alternate molecular assembly of GO/Ti<sub>0.87</sub>O<sub>2</sub><sup>0.52−</sup> was fabricated layer-by-layer, and this film showed enhanced carrier transport properties after photocatalytic reduction.