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Yamamuro Group

member
Professor YAMAMURO, Osamu
Research Associate AKIBA, Hiroshi

Research Subjects

  • Structure and dynamics of glasses and supercooled liquids
  • Structure and dynamics of water and related materials (e.g., gas hydrates)
  • Thermal and dynamical properties of ionic liquids
  • Structure and dynamics of guest molecules and ions confined in porous materials

We are studying chemical physics of complex condensed matters, especially glasses and supercooled liquids, water and related materials, ionic liquids, and porous materials. Glass transition is a mysterious phenomenon in which liquids solidify without structural change. This is one of the big and long-standing issues in physics. Water, which is the most familiar material for us, exhibits various unique phenomena caused by hydrogen bonds. Ionic liquids have nanometer-size domains and hierarchical dynamics generated by competing electrostatic and van der Waals interactions. Molecules and ions confined in porous materials such as MOF (Metal Organic Framework) give rise to unusual structure and dynamics caused by the surface effects and resultant distorted potential energy surfaces. These substances are investigated by neutron scattering, x-ray diffraction, heat capacity, and dielectric measurements. Our aim is to find simple (?) rules involved in complex systems from the three different points of view, i.e., structure, dynamics, and thermodynamic.

Reduced pair distribution functions of liquid and glassy CS2. These data clearly indicate that the intermolecular correlation becomes gradually larger on cooling and drastically sharpened at a glassy state. Reverse Monte Carlo analysis revealed that the most preferred pair correlation is T-shaped.
Quasielastic neutron scattering data and the result of the fitting with a Lorentz function for a MOF (Metal Organic Framework) called MIL-53. This material is a proton conductor with carriers of water molecules.

Publications and Research Highlights