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Matsuo, Yoji*; Mori, Shigeo*; Hirata, Akihiko*; Yoshii, Kenji; Ikeda, Naoshi*
Journal of Physics; Conference Series, 200, p.012128_1 - 012128_4, 2010/02
Times Cited Count:3 Percentile:74.25(Materials Science, Multidisciplinary)RFeO (R= Ho-Lu,Y) is a novel ferroelectric material in which ferroelectric polarization is caused by the charge ordering (CO) of Fe and Fe. In this work we investigated the CO structure and dielectric/magnetic properties in RFeO and RFeCuO (R=Lu,Yb, M=Cu,Co) by a transmission electron microscopy (TEM), combining with dielectric and magnetic measurements. LuFeCuO is a dielectric compound, which shows the characteristic low-frequency dielectric dispersion. In addition, the Cu substitution in LuFeO suppressed the formation of the CO structure and induced characteristic polar nanodomains with the 5-10nm size. Magnetic measurement revealed that LuFeCuO shows the magnetic transition around 50K, which is much lower than the magnetictransition temperature of 250K in LuFeO. Our experimental results suggest that the polar nanodomains should be responsible for the magnetic/dielectric properties in RFeMO.
Matsuo, Yoji*; Hirata, Akihiko*; Horibe, Yoichi*; Yoshii, Kenji; Ikeda, Naoshi*; Mori, Shigeo*
Ferroelectrics, 380(1), p.56 - 62, 2009/06
Times Cited Count:6 Percentile:29.51(Materials Science, Multidisciplinary)Diluted effect on the charge ordered (CO) structure in dielectric materials LuFeO (=Cu, Co) were investigated by an energy-filtered transmission electron microscope (TEM), in combination with a conventional TEM. It is revealed that partial substitution of Cu and Co for Fe in LuFeO destabilized the CO structure. In LuFeCuO, there exist characteristic zigzag-shaped diffuse streaks and diffuse spots at the h/3- h/3- 0-type positions (h: integer, =0.06) in reciprocal space, which originate from static cationic ordering of Fe and Cu ions in the triangular lattice. Moreover, real-space images by the energy-filtered TEM revealed that nanometer-sized domain structures with the 510 nm size are formed. In contrast, honeycomb-shaped diffuse streaks were found in LuFeCoO, in which no domain structures are observed in real-space images.
Nagame, Yuichiro; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Ishii, Yasuo; Sato, Tetsuya; Hirata, Masaru; Nishinaka, Ichiro; Ichikawa, Shinichi; et al.
Radiochimica Acta, 93(9-10), p.519 - 526, 2005/00
Times Cited Count:30 Percentile:87.1(Chemistry, Inorganic & Nuclear)no abstracts in English
Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Nishinaka, Ichiro; Hirata, Masaru; Yaita, Tsuyoshi; Ichikawa, Shinichi; Nagame, Yuichiro; et al.
Journal of the American Chemical Society, 126(16), p.5219 - 5224, 2004/04
Times Cited Count:43 Percentile:72.51(Chemistry, Multidisciplinary)Fluoride complexation of element 104, rutherfordium (Rf), produced in the Cm(O,5n)Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchangechromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effect on the fluoride complexation of Rf.
Haba, Hiromitsu; Tsukada, Kazuaki; Asai, Masato; Goto, Shinichi*; Toyoshima, Atsushi; Nishinaka, Ichiro; Akiyama, Kazuhiko; Hirata, Masaru; Ichikawa, Shinichi; Nagame, Yuichiro; et al.
Journal of Nuclear and Radiochemical Sciences, 3(1), p.143 - 146, 2002/06
We have investigated the sorption behavior of element 104 rutherfordium (Rf) on an anion exchange resin from HCl and HNO solutions. In the HCl experiments, the distribution coefficients of Rf increase with an increase of HCl concentration from 7.0 M to 11.5 M, indicating that anionic species such as [Rf(OH)Cl] or [RfCl] are formed. This sorption behavior of Rf is typical of the group-4 elements Zr and Hf, and is quite different from that of the pseudo-homologue Th. It is also noted that the distribution coefficients decrease in the order Rf, Zr, Hf at 9.0 M HCl, which is consistent with the expected order of ionic radii. On the other hand, Rf appears to behave like Zr and Hf in 8 M HNO not like Pu and Th.
Haba, Hiromitsu; Tsukada, Kazuaki; Asai, Masato; Nishinaka, Ichiro; Sakama, Minoru*; Goto, Shinichi*; Hirata, Masaru; Ichikawa, Shinichi; Nagame, Yuichiro; Kaneko, Tetsuya*; et al.
Radiochimica Acta, 89(11-12), p.733 - 736, 2002/02
Times Cited Count:14 Percentile:68.97(Chemistry, Inorganic & Nuclear)no abstracts in English
Tsukada, Kazuaki; Toyoshima, Atsushi; Haba, Hiromitsu*; Asai, Masato; Akiyama, Kazuhiko*; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Ichikawa, Takatoshi; et al.
no journal, ,
no abstracts in English