hamon
Online ISSN : 1884-636X
Print ISSN : 1349-046X
ISSN-L : 1349-046X
Volume 27 , Issue 2
Showing 1-6 articles out of 6 articles from the selected issue
  • Toshio Yamaguchi
    2017 Volume 27 Issue 2 Pages 55-58
    Published: 2017
    Released: November 14, 2018
    JOURNALS FREE ACCESS

    Unique properties of liquids and various processes in solutions originate from the solute-solute, solute-solvent, and solvent-solvent interactions in solutions. The structure and dynamics of liquids and solutions on the molecular level are thus essential for understanding the function and underlying mechanism of processes in solutions. Quantum beams, such as X-rays and neutrons, are of similar length and time scale as ions and molecules and are suited for this aim. Novel neutron scattering techniques for liquids and solutions have been developed for measurements over a wide range of concentration, temperature, and pressure. The techniques have been applied to various liquid systems, such as electrolyte solutions, supercritical fluids, confined and interfacial liquids, and solvent-induced denaturation of proteins.

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  • Minoru Soda
    2017 Volume 27 Issue 2 Pages 59-62
    Published: 2017
    Released: November 14, 2018
    JOURNALS FREE ACCESS

    The origin of multiferroics in the proper-screw magnetic structure, the superparamagnetism in relaxor ferroelectrics with the magnetic ions, and the magnetic anisotropy induced by the spin-nematic interaction were studied mainly by using the neutron scattering method by focusing on the relationship between the magnetism and the dielectricity. In these studies, a novel coupling between the magnetism and dielectricity, which is different from that in the typical multiferroics with the cycloidal magnetic structure, was discovered. Our new finding will open the door to a novel magnetoelectric effect.

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  • Taro Nakajima
    2017 Volume 27 Issue 2 Pages 63-66
    Published: 2017
    Released: November 14, 2018
    JOURNALS FREE ACCESS

    We have investigated effects of uniaxial stress on frustrated magnets by means of neutron scattering experiment. In this article, we focus on a triangular lattice antiferromagnet CuFeO2, which exhibits a strong spin-lattice coupling. We demonstrated uniaxial-stress control of electric polarization in a multiferroic phase of Ga-doped CuFeO2. We also studied magnetic excitations in the collinear four-sublattice (4SL) antiferromagnetic ground state in undoped CuFeO2 by means of inelastic neutron scattering measurements under uniaxial stress. We suggest that application of uniaxial-stress can be a useful tool to investigate geometrically frustrated spin systems, and can also induce novel cross-correlated phenomena in spin-lattice coupled systems.

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  • Shinichi Itoh, Yasuo Endoh, Tetsuya Yokoo, Soshi Ibuka, Je-Geun Park, ...
    2017 Volume 27 Issue 2 Pages 67-70
    Published: 2017
    Released: November 14, 2018
    JOURNALS FREE ACCESS

    Magnetic excitations in a polycrystalline sample of the metallic ferromagnet SrRuO3 were observed by neutron Brillouin scattering, i.e., inelastic neutron scattering near the forward direction, on the High Resolution Chopper Spectrometer (HRC) installed at MLF J-PARC. While the observed spin wave dispersion is well described by the quadratic momentum dependence, the temperature dependence of the spin wave gap shows a nonmonotonous behavior, which can be related to that of the anomalous Hall conductivity. Weyl fermions that emerge at band crossings in momentum space caused by the spin-orbit interaction act as magnetic monopoles of the Berry curvature and contribute to a variety of novel transport phenomena such as anomalous Hall effect. The present result shows that the fictitious magnetic field produced by the Berry phase is an observable in inelastic neutron scattering and that the spin dynamics directly reflects the crucial role of Weyl fermions in the metallic ferromagnet.

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