Influence of electron doping on magnetic order in CeRuAl

Kobayashi, Riki*; Kaneko, Koji; Saito, Kotaro*; Mignot, J.-M.*; Andr, G.*; Robert, J.*; Wakimoto, Shuichi; Matsuda, Masaaki*; Chi, S.*; Haga, Yoshinori; et al.

Journal of the Physical Society of Japan, 83(10), p.104707_1 - 104707_5, 2014/10

https://doi.org/10.7566/JPSJ.83.104707

Neutron diffraction of ice in hydrogels

Sekine, Yurina; Fukazawa, Tomoko*; Aizawa, Mamoru*; Kobayashi, Riki*; Chi, S.*; Fernandez-Baca, J. A.*; Yamauchi, Hiroki; Fukazawa, Hiroshi

Journal of Physical Chemistry B, 118(47), p.13453 - 13457, 2014/08

https://doi.org/10.1021/jp508269b

Neutron diffraction patterns for deuterated poly-,,-dimethylacrylamide (PDMAA) hydrogels were measured from 10 to 300 K to investigate the structure and properties of water in the gels. Diffraction peaks observed below 250 K indicate the existence of ice in the hydrogels. Some diffraction peaks from the ice are at lower diffraction angles than those in ordinary hexagonal ice (Ih). These shifts in peaks indicate that the lattice constants of the and axes in the ice are about 0.29% and 0.3% higher than those in ice Ih, respectively. The results show that bulk low-density ice can exist in PDMAA hydrogels. The distortions in the lattice structure of ice imply significant interactions between water molecules and the surrounding polymer chains, which play an important role in the chemical and mechanical properties of the hydrogel.

Powder neutron diffraction study of HoCoGa

Kobayashi, Riki; Kaneko, Koji; Wakimoto, Shuichi; Chi, S.*; Sanada, Naoyuki*; Watanuki, Ryuta*; Suzuki, Kazuya*

Journal of the Korean Physical Society, 63(3), p.337 - 340, 2013/08

https://doi.org/10.3938/jkps.63.337

Neutron diffraction study of hydrogels

Sekine, Yurina; Fukazawa, Tomoko*; Kobayashi, Riki*; Chi, S.*; Fernandez, J.*; Fukazawa, Hiroshi

no journal, , 

Hydrogels are unique materials that can contain a large amount of water in their three-dimensional polymer chain networks. We used neutron diffraction to probe the structure of DO in poly-,,-dimethylacrylamide (PDMAA) hydrogel. Two PDMAA hydrogels with high and low DO-content W (W = 0.9 and 0.5) were prepared. The neutron diffraction measurements were performed using the Wide Angle Neutron Diffractometer (WAND) at the High Flux Isotope Reactor in Oak Ridge, U.S.A. The samples were rapidly cooled using liquid nitrogen, and then heated from 10 to 300 K. The neutron diffraction profiles of the high DO-content PDMAA gel (W = 0.9) have strong sharp peaks below 270 K that are similar to diffraction patterns of hexagonal ice Ih. At 300 K, the profile has a broad liquid-like diffraction feature. The profile of the gel at W = 0.5 has a broad band in the 2 range from 20 - 28 below 230 K that are similar to diffraction pattern of glassy water. Sharp peaks are observed in the profile at 230 K. The feature of the profile is similar to that of cubic ice. The profile at 260 K has ice Ih-like strong peaks. Our neutron diffraction results show the existence of ice in hydrogels and that the structure of ice depends on the water content of the hydrogel. The structural changes of ice in hydrogels might have important implications in the interpretation of hydrogel properties, for both biological tissues and synthetic gel materials.

Rh substitution effect of CeRuAl

Kobayashi, Riki; Kawamura, Yukihiro*; Hirai, Daishi*; Nishioka, Takashi*; Kato, Harukazu*; Matsumura, Masahiro*; Matsubayashi, Kazuyuki*; Uwatoko, Yoshiya*; Kaneko, Koji

no journal, , 

no abstracts in English

Search for novel response induced by anharmonic thermal motion in filled skutterudite PrOsSb

Kaneko, Koji; Wakimoto, Shuichi; Kobayashi, Riki; Matsuda, Tatsuma; Tsutsui, Satoshi*; Chi, S.*; Kimura, Hiroyuki*; Noda, Yukio

no journal, , 

no abstracts in English

Effect of the Ru-site substitution on CeRuAl, 3

Kobayashi, Riki; Kaneko, Koji; Wakimoto, Shuichi; Haga, Yoshinori; Matsuda, Tatsuma; Yamamoto, Etsuji; Robert, J.*; Mignot, J.-M.*; Andr, G.*; Matsuda, Masaaki*; et al.

no journal, , 

no abstracts in English