hamon
Online ISSN : 1884-636X
Print ISSN : 1349-046X
ISSN-L : 1349-046X
Volume 16 , Issue 1
Showing 1-19 articles out of 19 articles from the selected issue
  • Mitsuru Itoh
    2006 Volume 16 Issue 1 Pages 3-7
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Properties and the crystal structures of novel complex oxides were introduced based on the recent experimental results of the author's group. Results of lithium ion conductor, ferroelectrics, magnetic conductor, and quasi-one-dimensional magnet were explained from the viewpoints of the structure and the chemical bond.
    Download PDF (12172K)
  • Nozomu Hamaya
    2006 Volume 16 Issue 1 Pages 8-11
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Understanding of the pressure evolution of physical and chemical properties of hydrogen is the ultimate goal of the high pressure science. This purpose has stimulated the development of low-temperature high-pressure technique for neutron diffraction study. With benefit of high intensity neutron sources a new diamond anvil cell (DAC) has been invented by I. N. Goncharenko. This device allows us to study neutron diffraction under extreme conditions of pressures up to 50 GPa, temperatures down to 0.1K and applied magnetic fields up to 7.5 T. We describe the details of this technique in the hope that J-PARC will make an epoch in ultra-high-pressure research.
    Download PDF (4641K)
  • Ryousuke Shiina
    2006 Volume 16 Issue 1 Pages 12-16
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    In this report we review recent theoretical studies on antiferro-quadrupolar orders in CeB6 and PrOs4Sb12. Their characteristic phase diagrams originating from (quasi-) quartet crystal field levels are shown to provide a good opportunity to study orbital degrees of freedom of f electrons. The important role of neutron scattering experiments in studying hidden multipoles and their dynamic fluctuations is discussed.
    Download PDF (9048K)
  • Toru Moriya
    2006 Volume 16 Issue 1 Pages 17-19
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Wishfull discussions are given for precise neutron scattering measurements of spin fluctuations around the magnetic quantum critical point, in the pseudogap region of underdoped high-Tc cuprates, in frustrated spin systems and in ferromagnetic iron.
    Download PDF (593K)
  • Yoshinori Haga
    2006 Volume 16 Issue 1 Pages 20-23
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Recent activities on magnetism and superconductivity research in transuranium compounds in Japan are shown. Single crystals of PuRhGa5 and PuIn3 have been successfully grown and the anisotropic superconducting upper ctirical field and Fermi surfaces were revealed, respectively.
    Download PDF (7533K)
  • Yoshio Kitaoka
    2006 Volume 16 Issue 1 Pages 24-27
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    We report on an intimate interplay between superconductivity (SC) and antiferromagnetism (AFM) in CeRhIn5 under pressure and multilayered high-Tc cuprates via the NMR/NQR measurements. The experiments on CeRhIn5 has revealed that a first-order quantum phase transition (QPT) occurs around Pc-2 GPa from the AFM to the paramagnetism in the superconducting regime and the novel superconducting nature in the coexistent phase of AFM and SC. The site selective Cu-NMR study demonstrated that the under-doped five-layered high-Tc cuprate, HgBa2Ca4Cu5O12+δ with Tc=72 K can uniformly coexist on the microscopic level with the AFM. This is the first microscopic evidence for the uniform mixed phase of AFM and SC on a single CuO2 plane in a simple environment without any vortex lattice and/or stripe order.
    Download PDF (9006K)
  • Koichi Kindo
    2006 Volume 16 Issue 1 Pages 28-31
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    A few types of pulse-magnets are introduced to start discussion to make a new magnet for neutron experiments in high magnetic field. At first, simple solenoid type magnets are introduced. Both short-and long-pulse-magnets have become to generate 80 T-class fields non-destructively. The pulse duration varies between 0.1 and 100 msec. depending on the available current source. Split-pair type magnet has been developed for X-ray diffraction measurements in high magnetic field at SPring-8 and it is going to produce a 50 T-class field. A short pulse magnet with a high repetition for pulse neutron experiments is also proposed.
    Download PDF (8504K)
  • Wataru Higemoto
    2006 Volume 16 Issue 1 Pages 32-35
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Experimental method, which detects local magnetic field by using muon, is known as muon spin rotation/relaxation/resonance (μSR) method.μSR has extremely high sensitivity for local magnetism and is complementary technique with neutron experiment. For example, detectable time window of μSR is different from neutron experiment. In this article, we introduce the μESR technique and it's application. Both muon and neutron experimental facility will be located in same J-PARC materials and life science facility building. Here I wish to have a good scientific communication as the facilities in the next at J-PARC.
    Download PDF (4839K)
  • Takashi Odagaki
    2006 Volume 16 Issue 1 Pages 36-39
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    A free energy landscape (FEL) picture of the glass transition is presented, which provides a unified understanding of glass transition singularities.This view is a straight forward generalization of the Landau theory of phase transitions with atomic configuration in place of the order parameter.Exploiting the density functional theory, we show that the FEL can really be calculated and argue that there are two kinds of cooperatively rearranging regions: One is the region defined by the difference between two adjacent basins, which could be called a simultaneously rearranging region, and the other is the atoms involved in the excited state between two adjacent basins.We obtain the FEL for a relaxation process which is characterized by a string motion and determine the size of the cooperatively rearranging region.
    Download PDF (753K)
  • Fuyuki Shimojo
    2006 Volume 16 Issue 1 Pages 40-43
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    The recent development of ab initio simulation techniques enables us to carry out reliable simulations for liquid-state materials. As an example, we describe the results of ab initio molecular-dynamics simulations for liquid alkali-chalcogen mixtures and molten noble-metal halides. It is shown that the calculated structure factors are in good agreement with those obtained by neutron scattering experiments. We discuss the relationship between ab initio studies on liquids and neutron experiments from the viewpoint of theoretical research.
    Download PDF (769K)
  • Seiji Kojima
    2006 Volume 16 Issue 1 Pages 44-47
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Dynamical properties of lithium borate glass are studied by the measurements of complex heat capacity, ultrasonic velocity, Raman scattering and terahertz-time domain spectroscopy. The non-Debye nature of structural relaxation, anharmonicity and boson peak are discussed in relation with fragility.
    Download PDF (3691K)
  • Takao Ohta
    2006 Volume 16 Issue 1 Pages 48-51
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    One of the characteristic features of soft matter is to cause various mesoscopic structures in thermal equilibrium. Identification and the properties of the structures have been investigated by transmission electron microscopy, rheological measurements and scattering experiments. Here we briefly review recent theoretical studies of formation and transitions of mesoscopic structures in microphase separated diblock copolymers.
    Download PDF (11550K)
  • Takeshi Yamada, Hirohisa Yoshida
    2006 Volume 16 Issue 1 Pages 52-55
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Phase transitions of nano-scale ordered amphiphilic molecules and di-block copolymers were investigated by the simultaneous differential scanning calorimetry and X-ray diffraction method (DSC-SAXS). Alkyl ammonium type monomer formed bilayer structure on solid surfaces, and bilayer structure was fixed in it's polymer by the irradiation of electrone beam or X-ray at the melting of monomer. The polymerization occurred at the bilayer interface, where monomers established the closest alignment at the melting. The phase transitions of liquid crystalline type amphphilic di-block copolymers were assigned by DSC-SAXS method. The interface between hydrophilic and hydrophobic domains of amphiphic di-block copolymers was characterized by thermodynamic and profile fitting methods.
    Download PDF (5072K)
  • Hiroshi Watanabe
    2006 Volume 16 Issue 1 Pages 56-59
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Non-Newtonian flow behavior was examined for butadiene-styrene (BS) diblock and BSB triblock copolymers dissolved in a S-selective solvent, dibutyl phthalate (DBP). Spherical domains of the non-solvated B blocks were arranged on a bcc lattice in both solutions at equilibrium, as revealed from small-angle neutron scattering (SANS). The solutions exhibited significant thinning under steady flow, which was well correlated with the disruption of the bcc lattice detected with SANS. The lattice disruption was most prominent at a shear rate comparable to the frequency of B/S concentration fluctuation. For the BS/DBP solution, the recovery of the lattice structure after cessation of flow was the slowest for the most heavily disrupted lattice, as naturally expected. In contrast, for the BSB/DBP solution, the recovery rate was insensitive to the magnitude of lattice disruption. This peculiar behavior of the BSB solution suggests that the rate-determining step of the recovery in this solution is the transient B/S mixing required for reformation of the S bridges connecting the B domains.
    Download PDF (694K)
  • Tetsuro Fujisawa
    2006 Volume 16 Issue 1 Pages 60-63
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    The use of high hydrostatic pressure has been a useful tool for studying physicochemical properties of proteins. Since proteins change their volume during reactions, pressure perturbs the equilibria and the relative populations, between the multiple conformers. We have been developing a high-pressure cell for HP-SAXS that has a small sample volume (ca. 0.05mL) and sufficiently high reproducibility, to collect solution scattering data from large protein complexes. We report the present status of the development and its application for large protein complex.
    Download PDF (759K)
  • Kenichi Yoshikawa
    2006 Volume 16 Issue 1 Pages 64-67
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    The difference of the fluctuation between equilibrium and thermodynamically open systems is discussed. Under linear regimes in the non-equilibricity, fluctuation always causes the destruction of spatial and temporal structures. In contract, under nonlinear regime spontaneous symmetry breaking of the spatio-temporal structure is generated driven by fluctuation. From actual experiments concerning the spontaneous motion of an liquid droplet, it is shown that non-equilibrium fluctuation causes regular motion, accompanied by the reduction of the vast number of freedoms. It is expected that the essential scenario on the energy transduction from chemical into regular motion in molecular machinery exhibits its theoretical basis on the exotic effect of non-equilibrium fluctuation.
    Download PDF (8711K)
  • Michiyo Kaneko
    2006 Volume 16 Issue 1 Pages 68-69
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Currently, automotive industry is faced with a strong necessity of developing hybrid vehicle and fuel cell in the energy and environmental point of view. In the R&D of such vehicles, it becomes very important to know what is happening in light element at actually working (in-situ) condition. We expect neutron related techniques as promising ones for such research. In addition to the expectation, we would like to express our opinion as an industrial user.
    Download PDF (7630K)
  • Toru Yasuda, Hideki Mochizuki, Keiji Wada, Sachio Naito
    2006 Volume 16 Issue 1 Pages 70-74
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    Molecular shape of proteins and the formation of the polymeric structures of their self-assembled bodies and the aggregates seriously damage the cell, since, as a typical topics, the abnormal aggregation of the proteins observed in the Parkinson's disease and Alzheimer's disease has suggested causing the neurofibrilary degeneration and the final cell death. We are studying the abnormal brain proteins aggregation in water by small-angle neutron scattering. Here, we demonstrated the structure of UCH-L1 (ubiqutin carboxy-terminal hydrolase L1) concerning the proteasome system in water. The mutant and the polymorphism are closely related to the Parkinsonism.
    Download PDF (12506K)
  • Tatsumi Hirano
    2006 Volume 16 Issue 1 Pages 75-78
    Published: January 15, 2006
    Released: January 27, 2011
    JOURNALS FREE ACCESS
    The giant magnetoresistive head, consisting of magnetic and noble metal multilayers, is a key device of hard disk drives. As head properties strongly depend on the magnetic structure, the characterization is important for producing good devices. In this report, we review multi-wave x-ray reflectometry for accurate analysis of the layer thickness, and polarized neutron reflectometry for analysis of magnetic moment. We also mention a future prospect of a neutron experiment.
    Download PDF (617K)
feedback
Top