Effect of starch retrogradation on molecular dynamics of cooked rice by quasi-elastic neutron scattering

Hirata, Yoshinobu*; Nakagawa, Hiroshi; Yamauchi, Hiroki; Kaneko, Koji; Hagihara, Masato; Yamaguchi, Hideyuki*; Omoto, Chie*; Katsuno, Nakako*; Imaizumi, Teppei*; Nishizu, Takahisa*

Food Hydrocolloids, 141, p.108728_1 - 108728_7, 2023/08

https://doi.org/10.1016/j.foodhyd.2023.108728

Crystallinity is reflected in the mechanical properties of foods and materials. Crystallinity should be related to the structural dynamics of starch. In this study, we used quasi-elastic neutron scattering (QENS) to investigate changes in the molecular dynamics of cooked rice starch during retrogradation. The width of the measured QENS narrowed with retrogradation. The elastic incoherent structure factor (EISF) increased, which indicated that the molecular dynamics are spatially suppressed upon retrogradation. Analysis of EISF with a bimodal continuous diffusion model, where low and high mobilities are assumed to correspond to crystalline and amorphous phases, respectively, showed that the fraction of the low-mobility component increases with retrogradation.

Spin gap in the weakly interacting quantum spin chain antiferromagnet KCuPOHO

Fujihara, Masayoshi; Hagihara, Masato; Morita, Katsuhiro*; Murai, Naoki; Koda, Akihiro*; Okabe, Hirotaka*; Mitsuda, Setsuo*

Physical Review B, 107(5), p.054435_1 - 054435_8, 2023/02

https://doi.org/10.1103/PhysRevB.107.054435

The = 1/2 Heisenberg linear chain antiferromagnet is the simplest spin model; nevertheless it serves as a platform for various quantum many-body phenomena. Here, we report the magnetic behavior of a quasi-one-dimensional antiferromagnet KCuPOHO. A long-range commensurate antiferromagnetic order with ordered moment 0.31(1) per spin occurs at = 11.7(1) K. Above , the inelastic neutron excitation is characterized by a two spinon continuum. The intrachain interaction and interchain interaction are estimated to be 172 K and 4.25(4) K, respectively; thus the ratio of the / = 0.0247(3). At lower energies, below , a spin gap is observed in the dispersive excitations. These results are consistent with characteristics observed in weakly interacting = 1/2 Heisenberg chain system.

Hyperfine splitting and nuclear spin polarization in NdPdAl and NdPdGe

Metoki, Naoto; Shibata, Kaoru; Matsuura, Masato*; Kitazawa, Hideaki*; Suzuki, Hiroyuki*; Yamauchi, Hiroki; Hagihara, Masato; Frontzek, M. D.*; Matsuda, Masaaki*

Journal of the Physical Society of Japan, 91(5), p.054710_1 - 054710_6, 2022/05

https://doi.org/10.7566/JPSJ.91.054710

Hyperfine splitting of Nd nuclei in NdPdAl has been studied by means of high-resolution neutron spectroscopy. We observed inelastic peaks at eV coming from the hyperfine splitting in the magnetically ordered phase due to the hyperfine interactions between Nd nuclei (=7/2) and the 4 electrons with ground state composed of mainly . At very low temperatures, nuclear spin of Nd is polarized with increasing occupation probability of low energy levels and contributes to the enhancement of the antiferromagnetic Bragg intensities: the elastic non-spin-flip channel is dominant. As an application of this phenomenon, we determined the Nd moment and hyperfine splitting from the temperature dependence of an antiferromagnetic Bragg intensities for NdPdGe.

Sinusoidal magnetic structure of andalusite-type AlxFe-xGeO with = 0.09 and 0.15

Kakimoto, Kazuo*; Ota, Hiroto*; Haraguchi, Yuya*; Hagihara, Masato; Torii, Shuki*; Kamiyama, Takashi*; Katori, Hiroko*

Journal of the Physical Society of Japan, 91(5), p.054707_1 - 054707_9, 2022/05

https://doi.org/10.7566/JPSJ.91.054707

Contrasting magnetic structures in SrLaCuSbO and SrLaCuNbO; Spin- quasi-square-lattice - Heisenberg antiferromagnets

Watanabe, Masari*; Kurita, Nubuyuki*; Tanaka, Hidekazu*; Ueno, Wataru*; Matsui, Kazuki*; Goto, Takayuki*; Hagihara, Masato

Physical Review B, 105(5), p.054414_1 - 054414_12, 2022/02

https://doi.org/10.1103/PhysRevB.105.054414

Coexistence of magnetoelectric and antiferroelectric-like orders in MnTaO

Kimura, Kenta*; Yagi, Naoki*; Hasegawa, Shunsuke*; Hagihara, Masato; Miyake, Atsushi*; Tokunaga, Masashi*; Cao, H.*; Masuda, Takatsugu*; Kimura, Tsuyoshi*

Inorganic Chemistry, 60(20), p.15078 - 15084, 2021/10

https://doi.org/10.1021/acs.inorgchem.1c02461

High-temperature short-range order in MnRhSi

Yamauchi, Hiroki; Sari, D. P.*; Watanabe, Isao*; Yasui, Yukio*; Chang, L.-J.*; Kondo, Keietsu; Ito, Takashi; Ishikado, Motoyuki*; Hagihara, Masato*; Frontzek, M. D.*; et al.

Communications Materials (Internet), 1, p.43_1 - 43_6, 2020/07

https://doi.org/10.1038/s43246-020-0042-1

High-temperature short-range order is discovered up to 720 K in MnRhSi by complementary use of neutron scattering and muon spin relaxation measurements.

The -electron state of the heavy fermion superconductor NpPdAl and the isostructural family

Metoki, Naoto; Aczel, A. A.*; Aoki, Dai*; Chi, S.*; Fernandez-Baca, J. A.*; Griveau, J.-C.*; Hagihara, Masato*; Hong, T.*; Haga, Yoshinori; Ikeuchi, Kazuhiko*; et al.

JPS Conference Proceedings (Internet), 30, p.011123_1 - 011123_6, 2020/03

https://doi.org/10.7566/JPSCP.30.011123

Rare earths (4) and actinides (5) provide variety of interesting states realized with competing interactions between the increasing number of electrons. Since crystal field splitting of many-body electron system is smaller than the bandwidth, (1) high resolution experiments are needed, (2) essentially no clear spectrum with well defined peaks is expected in itinerant Ce and U compounds, and (3) Np and Pu is strictly regulated. Therefore, systematic research on magnetic excitations by neutron scattering experiments of localized compounds and rare earth iso-structural reference is useful. We describe the electron states of heavy electron compounds NpPdAl and actinide and rare earth based iso-structural family.

-electron states in PrPdAl

Metoki, Naoto; Yamauchi, Hiroki; Suzuki, Hiroyuki*; Kitazawa, Hideaki*; Hagihara, Masato*; Masuda, Takatsugu*; Aczel, A. A.*; Chi, S.*; Hong, T.*; Matsuda, Masaaki*; et al.

Journal of the Physical Society of Japan, 87(9), p.094704_1 - 094704_8, 2018/09

https://doi.org/10.7566/JPSJ.87.094704

The -electron states of PrPdAl were revealed by neutron inelastic scattering. The flat -orbitals with large become stable under the two-dimensional CEF potential of unique crystal structure, which is the origin of the Ising anisotropy. A systematic understanding is possible in RPdAl based on this CEF potential. Especially the -type anisotropy in NpPdAl can be qualitatively understood with the positive Stevens factors. It mean that the local property is important for the physical properties of RPdAl including the heavy fermion superconductivity in NpPdAl.

Neutron powder diffraction study on the magnetic structure of NdPdAl

Metoki, Naoto; Yamauchi, Hiroki; Kitazawa, Hideaki*; Suzuki, Hiroyuki*; Hagihara, Masato*; Frontzek, M. D.*; Matsuda, Masaaki*; Fernandez-Baca, J. A.*

Journal of the Physical Society of Japan, 86(3), p.034710_1 - 034710_5, 2017/03

https://doi.org/10.7566/JPSJ.86.034710

Magnetic structure of NdPdAl has been studied by means of neutron powder diffraction. We observed remarkable magnetic reflections with the modulation vector = (1/2 0 0) below the ordering temperature = 1.2 K. We found a collinear magnetic structure of Nd moment of 2.9(1) at 0.3 K parallel to the -axis, where the ferromagnetically ordered planes stack with four Nd layer period of ++-- sequence along the direction with the distance between adjuscent Nd layers to be . This is very similar to CePdAl with = (0.23 0.23 0) and the Ce moment parallel to the -axis. These structures with in-plane modulation is a consequence of the two dimensional nature of fermi surface topology in this family, coming from unique crystal structure with very long tetragonal unit cell and large distance 7 between the rare earth layers separated by Al and two Pd layers.