A5029521396- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Advanced Thermoelectric Materials and Devices
- Chalcogenide Semiconductor Thin Films
- Crystallography and molecular interactions
- Thermal Expansion and Ionic Conductivity
- High-pressure geophysics and materials
- Catalytic Processes in Materials Science
- Luminescence and Fluorescent Materials
- Boron and Carbon Nanomaterials Research
- 2D Materials and Applications
- Phase-change materials and chalcogenides
- Nuclear materials and radiation effects
- Rare-earth and actinide compounds
- Crystallography and Radiation Phenomena
- Iron-based superconductors research
- Metal-Organic Frameworks: Synthesis and Applications
- Gas Sensing Nanomaterials and Sensors
- Advanced Condensed Matter Physics
- Glass properties and applications
- Semiconductor materials and interfaces
- MXene and MAX Phase Materials
- Organic and Molecular Conductors Research
- Advancements in Solid Oxide Fuel Cells
- Magnetism in coordination complexes
University of Tsukuba
2016-2025
Guilin University of Electronic Technology
2023
Tohoku University
2020
National Institute for Materials Science
2018
Aarhus University
2016-2018
Aarhus School of Architecture
2017
SPring-8
2014-2016
Japan Science and Technology Agency
2014-2016
Hyogo University
2014-2016
The University of Tokyo
2009
We demonstrate a metal-organic framework (MOF) design for the inclusion of hydroxide ions. Salt method was applied to an alkaline-stable ZIF-8 (ZIF = zeolitic imidazolate framework) introduce alkylammonium hydroxides as ionic carriers. found that tetrabutylammonium salts are immobilized inside pores by hydrophobic interaction between alkyl groups salt and framework, which significantly increases hydrophilicity ZIF-8. Furthermore, including exhibited capacity OH(-) ion exchange, implying...
Ultrasmall metal oxide nanoparticles (<5 nm) potentially have new properties, different from conventional nanoparticles. The precise size control of ultrasmall remains difficult for oxide. In this study, the CeO2 was precisely controlled (1.3–9.4 using a continuous-flow hydrothermal reactor, and atomic distortion that occurs in oxides explored CeO2. crystalline grow rapidly like droplets via coalescence, although they reach critical particle (∼3 to 4 nm), beyond which slowly change shape...
Thermoelectric devices convert heat flow to charge flow, providing electricity. Materials for highly efficient must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. Thermal in caged compounds is known be suppressed by a large vibration guest atoms, so-called rattling, which effectively scatters phonons. Here, the crystal structure phonon dynamics tetrahedrites (Cu,Zn)12 (Sb,As)4 S13 are studied. The results reveal that Cu atoms planar...
We describe here the preparation of soft crystals using disilanyl macrocycle C4 possessing four p-phenylenes circularly connected by flexible disilane bonds. Single exhibited a reversible thermal single-crystal-to-single-crystal (SCSC) phase transition behavior between two crystal phases accompanied remarkable mechanical motion (thermosalient effect), as revealed analyses and X-ray diffraction measurements. Detailed structural implied that flexibility parallelogram architecture molecular...
To date, the high-temperature phase transition R3m$\text{\ensuremath{-}}Fm\phantom{\rule{0.83328pt}{0ex}}\overline{3}\phantom{\rule{0.83328pt}{0ex}}m$ in GeTe is commonly believed to be second-order displacive with an anomalous volume contraction at temperature, ${T}_{PT}$, from diffraction measurements. Three main results are here reported: (i) accompanied by latent heat absorption, (ii) high-resolution x-ray-diffraction powder pattern cubic appears before merging of rhombohedral peaks, and...
Six novel donor–acceptor–donor organic dyes containing a Si–Si moiety based on triarylamine functionalities as donor units were prepared by Pd-catalyzed arylation of hydrosilanes. Their photophysical, electrochemical, and structural properties studied in detail. Most the compounds showed attractive photoluminescence (PL) electrochemical both solution solid state because intramolecular charge transfer (ICT), suggesting these could be useful for electroluminescence (EL) applications. The...
Ultrafast changes of charge density distribution in diamond after irradiation with an intense x-ray pulse (photon energy, 7.8 keV; duration, 6 fs; intensity, $3\ifmmode\times\else\texttimes\fi{}{10}^{19}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$) have been visualized the pump--x-ray probe technique. The measurement reveals that covalent bonds are broken and electron around each atom becomes almost isotropic within $\ensuremath{\sim}5\text{ }\mathrm{fs}$ intensity maximum pump pulse. 15 fs...
A new sphalerite derivative compound, Cu 7 VSnS 8 , for thermoelectric applications was discovered using the pseudo-binary approach within “Cu 3 SnS 4 ”–“Cu VS ” system.
Atomic-scale defects/disorded states induced by sulfur sublimation are responsible for reduced lattice thermal conductivity of thermoelectric colusite.
The discovery of the ultra-high thermoelectric figure merit 2.6 in SnSe has drawn attention to other lead-free IV-VI orthorhombic semiconductors. GeSe been predicted possess performances comparable SnSe. Here, a complete structural study is reported with temperature by means high-resolution synchrotron powder X-ray diffraction. In phase, evolution bond distances shown deviate significantly respect Analysis chemical bonding within Quantum Theory Atoms Molecules shows that ionic van der Waals...
Pb- or Bi-based perovskite oxides have been widely studied and used because of their large ferroelectric polarization features induced by stereochemically active 6s(2) lone pair electrons. It is intriguing whether this effect could exist in other related systems. Herein, we designed synthesized a mixed Pb Bi A site polar compound, PbBiNb5O15, with the TTB framework. The as-synthesized material turns out to be relaxor weak macroscopic ferroelectricity but adopts strong local polarizations....
Ag doping in β-Zn<sub>4</sub>Sb<sub>3</sub> leads to the enhanced thermoelectric figure-of-merit (<italic>zT</italic>) and improved high-temperature thermal stability.
Abstract The Zn─Sb binary system contains two high‐performing thermoelectric materials, namely the ordered ZnSb and disordered Zn 13 Sb 10 . Both systems exhibit low thermal conductivity, which is speculated to originate from multicentre bonding within 2 ‐rhombi. Here, electron density of reported based on multipole modelling accurate X‐ray diffraction data measured at 20 K. Topological analysis reveals that bond paths in rhombus are endocyclically strained concentrated rather than along its...
The tetrahedrite Cu12Sb4S13 undergoes a metal–semiconductor transition (MST) at TMST = 85 K, whose mechanism remains elusive. Our Cu 2p X-ray photoemission spectroscopy study revealed the monovalent state of ions occupying two sites in this compound. This fact excludes possibilities previously proposed antiferromagnetic order and Jahn–Teller instability inherent divalent system. A synchrotron diffraction has that body-centered cubic cell transforms into 2a × 2c tetragonal supercell below...
While polymorphism is prevalent in crystalline solids, polyamorphism draws increasing interest various types of amorphous solids. Recent studies suggested that supercooling liquid phase-change materials (PCMs) induces Peierls-like distortions their local structures, underlying liquid-liquid transitions before vitrification. However, the mechanism how vitrified phases undergo a possible polyamorphic transition remains elusive. Here, using high-energy synchrotron X-rays, we can access precise...
The arc plasma deposition (APD) method is first applied to prepare metal–organic framework (MOF) composites loading metal nanoparticles having a direct contact with MOF.
Abstract Anharmonic lattice vibrations govern heat transfer in materials, and anharmonicity is commonly assumed to be dominant at high temperature. The textbook cubic ionic defect‐free crystal CsCl shown have an unexplained low thermal conductivity room temperature (ca. 1 W/(m K)), which increases around 13 K) 25 K. Through high‐resolution X‐ray diffraction it unexpectedly that the Cs atomic displacement parameter becomes anharmonic 20
A hybrid catalyst consisting of polymer-coated Ru nanoparticles embedded in a porous metal–organic framework ZIF-8 exhibits higher catalytic activity and CO<sub>2</sub> selectivity CO oxidation reaction with H<sub>2</sub> gas feeds.
SnTe is a promising thermoelectric and topological insulator material. Here, the presumably simple rock salt crystal structure of studied comprehensively by means high-resolution synchrotron single-crystal powder X-ray diffraction from 20 to 800 K. Two samples with different carrier concentrations (sample A = high, sample B low) have remarkably atomic displacement parameters, especially at low temperatures. Both contain significant numbers cation vacancies (1–2%) ordering Sn possibly occurs...
Serial femtosecond crystallography for small-unit-cell systems has so far seen very limited application despite obvious scientific possibilities. This is because reliable data reduction not been available these challenging systems. In particular, important intensity corrections such as the partiality correction critically rely on accurate determination of crystal orientation, which complicated by low number diffraction spots crystals. A pipeline capable fully automated handling all steps...
Charge densities of iso-structural metal hexaborides, a transparent LaB6 and semiconductor BaB6, have been determined using the d > 0.22 Å ultra-high resolution synchrotron radiation X-ray diffraction data by multipole refinement maximum entropy method (MEM). The quality experimental charge was evaluated comparison with theoretical densities. strong inter-octahedral relatively weak intra-octahedral boron-boron bonds were observed in A difference valence between BaB6 calculated to reveal...
Abstract Supramolecular chemistry under mechanochemical conditions has drawn attention because it can induce low‐solubility molecules to self‐assemble, although most of the reported examples have been limited two‐component systems. We applied synthesis achieve multimolecular self‐assembly in more challenging three‐component The produced crystals showed multicolor solid‐state luminescence depending on components when exposed UV light. Optical outputs and X‐ray diffraction studies were used...
A multi-temperature structural study of Mg 2 Si and Sn was carried out from 100 to 700 K using synchrotron X-ray powder diffraction. The temperature dependence the lattice parameters can be expressed as a = 6.3272 (4) + 6.5 (2) × 10 −5 T 4.0 (3) −8 Å 6.7323 (7) 8.5 3.8 (5) for Sn, respectively. atomic displacement (ADPs) are reported analysed Debye model averaged U iso giving temperatures 425 243 Sn. ADPs considerably smaller than reflecting weaker chemical bonding in structure. Following...