Quasielastic Neutron Scattering Study on Thermal Gelation in Aqueous Solution of Agarose.

The dynamics of water and agarose molecules in an agarose aqueous solution has been studied by means of quasielastic neutron scattering (QENS). The dynamic structure factor (,) of the agarose aqueous solution was fitted well to the sum of the Lorentz and delta function. The former is attributed to the diffusive motion of water molecules and the latter to the local vibrational motion of agarose molecules.

Time-Resolved Structural Analysis of Fast-Photoresponsive Surfactant Micelles by Stroboscopic Small-Angle Neutron Scattering.

Photoresponsive materials are garnering attention because of their applications toward building a sustainable society. A recently developed fast-photoresponsive amphiphilic lophine dimer (3TEG-LPD) responds rapidly to light, making it a promising candidate for drug-delivery systems. In this study, the mechanism of structural changes induced by ultraviolet (UV) irradiation in 3TEG-LPD micelles in an aqueous solution was investigated via an in situ time-resolved small-angle neutron scattering (SANS) technique.

Polarized Neutrons Observed Nanometer-Thick Crystalline Ice Plates in Frozen Glucose Solution.

Spin-contrast-variation (SCV) small-angle neutron scattering (SANS) is a technique to determine the nanostructure of composite materials from the scattering of polarized neutrons that changes with proton polarization of samples. The SCV-SANS enabled us to determine structure of nanoice crystals that were generated in rapidly frozen sugar solutions by separating the overlapped signals from the nanoice crystals and frozen amorphous solutions. In the frozen glucose solution, we found that the nanoice crystals formed a planar structure with a radius larger than several tens of nanometers and a thickness of 2.

Magnon mode transition in real space.

Spin excitation of an ilmenite FeTiO powder sample is measured by time-of-flight inelastic neutron scattering. The dynamic magnetic pair-density function D(r, E) is obtained from the dynamic magnetic structure factor S(Q, E) by the Fourier transformation. The real space spin dynamics exhibit magnon mode transitions in the spin-spin correlation with increasing energy from no-phase-shift to π-phase-shift.

Optimization and inference of bin widths for histogramming inelastic neutron scattering spectra.

A data-driven bin-width optimization for the histograms of measured data sets based on inhomogeneous Poisson processes was developed in a neurophysiology study [Shimazaki & Shinomoto (2007). , 1503-1527], and a subsequent study [Muto, Sakamoto, Matsuura, Arima & Okada (2019). , , 044002] proposed its application to inelastic neutron scattering (INS) data.

Quantum magnetisms in uniform triangular lattices LiAMoO (A = In, Sc).

Molecular based spin-1/2 triangular lattice systems such as LiZnMoO have attracted research interest. Distortions, defects, and intersite disorder are suppressed in such molecular-based magnets, and intrinsic geometrical frustration gives rise to unconventional and unexpected ground states. LiAMoO (A = In or Sc) is such a compound where spin-1/2 MoO clusters in place of Mo ions form the uniform triangular lattice.

Multiple-wavelength neutron holography with pulsed neutrons.

Local structures around impurities in solids provide important information for understanding the mechanisms of material functions, because most of them are controlled by dopants. For this purpose, the x-ray absorption fine structure method, which provides radial distribution functions around specific elements, is most widely used. However, a similar method using neutron techniques has not yet been developed.

Quasielastic neutron scattering studies on glass-forming ionic liquids with imidazolium cations.

Relaxation processes for imidazolium-based ionic liquids (ILs) were investigated by means of an incoherent quasielastic neutron scattering technique. In order to clarify the cation and anion effects on the relaxation processes, ten samples were measured. For all of the samples, we found three relaxations at around 1 ps, 10 ps, and 100 ps-10 ns, each corresponding to the alkyl reorientation, the relaxation related to the imidazolium ring, and the ionic diffusion.

Mode-distribution analysis of quasielastic neutron scattering and application to liquid water.

A quasielastic neutron scattering (QENS) experiment is a particular technique that endeavors to define a relationship between time and space for the diffusion dynamics of atoms and molecules. However, in most cases, analyses of QENS data are model dependent, which may distort attempts to elucidate the actual diffusion dynamics. We have developed a method for processing QENS data without a specific model, wherein all modes can be described as combinations of the relaxations based on the exponential law.

Pressure dependence of local structure in liquid carbon disulfide.

High pressure x-ray diffraction measurements on liquid carbon disulfide up to 1.2 GPa are performed by using an energy dispersion method. The results are compared with a molecular dynamics calculation with usual Lennard-Jones potential.

Macroscopic separation of dense fluid phase and liquid phase of phosphorus.

Structural transformation between a dense molecular fluid and a polymeric liquid of phosphorus that occurred at about 1 gigapascal and 1000 degrees C was investigated by in situ x-ray radiography. When the low-pressure fluid was compressed, dark and round objects appeared in the radiograph. X-ray diffraction measurements confirmed that these objects were the highpressure liquid.