Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
and O in a reaction cell in triple quadrupole inductively coupled plasma mass spectrometryKazama, Hiroyuki; Konashi, Kenji*; Suzuki, Tatsuya*; Koyama, Shinichi; Maeda, Koji; Sekio, Yoshihiro; Onishi, Takashi; Abe, Chikage*; Shikamori, Yasuyuki*; Nagai, Yasuyoshi*
Journal of Analytical Atomic Spectrometry, 38(8), p.1676 - 1681, 2023/07
Times Cited Count：0 Percentile：0.02(Chemistry, Analytical)Sato, Tetsuya; Nagame, Yuichiro*
Nihon Butsuri Gakkai-Shi, 78(2), p.64 - 72, 2023/02
The study of the chemistry of superheavy elements, which are located in the heavy extremes of the periodic table, has made considerable progress over the past 20 years, and new approaches based on various ideas have recently been developed. Research groups in Japan have also made significant contributions to the development of research on superheavy elements. Recently, notable results have been reported for the transactinide elements rutherfordium (element 104), dubnium (element 105), and seaborgium (element 106), and the heavy actinides with atomic numbers exceeding 100. The review will focus on the recent main results of these elements. This review outlines the main recent results and touches on future prospects.
Watanabe, Jin*; Araki, Yasufumi; Kobayashi, Koji*; Ozawa, Akihiro*; Nomura, Kentaro*
Journal of the Physical Society of Japan, 91(8), p.083702_1 - 083702_5, 2022/08
Times Cited Count：3 Percentile：58.88(Physics, Multidisciplinary)We investigate magnetic orderings on kagome lattice numerically from the tight-binding Hamiltonian of electrons, governed by the filling factor and spin-orbit coupling (SOC) of electrons. We find that even a simple kagome lattice model can host both ferromagnetic and noncollinear antiferromagnetic orderings depending on the electron filling, reflecting gap structures in the Dirac and flat bands characteristic to the kagome lattice. Kane-Mele- or Rashba-type SOC tends to stabilize noncollinear orderings, such a magnetic spirals and 120-degree antiferromagnetic orderings, due to the effective Dzyaloshinskii-Moriya interaction from SOC. The obtained phase structure helps qualitative understanding of magnetic orderings in various kagome-layered materials with Weyl or Dirac electrons.
Yokoi, Naoto*; Saito, Eiji
Journal of Magnetism and Magnetic Materials, 545, p.168673_1 - 168673_12, 2022/03
Times Cited Count：0 Percentile：0(Materials Science, Multidisciplinary)G
tz, M.*; Yakushev, A.*; Gtz, S.*; Di Nitto, A.*; D
llmann, Ch. E.*; Asai, Masato; Kindler, B.*; Krier, J.*; Lommel, B.*; Nagame, Yuichiro*; et al.
Radiochimica Acta, 110(2), p.75 - 86, 2022/02
Times Cited Count：2 Percentile：31.78(Chemistry, Inorganic & Nuclear)The study of volatile superheavy element carbonyl complexes requires more efficient methods because the yield of transactinide elements decreases with increasing atomic number. This is achieved by using a newly developed double chamber system to separate the recoil chamber and the reaction one, thereby avoiding the decomposition of reactive molecules by the projectile ion beam, which hinders the synthesis of carbonyl complexes. The feasibility of this method was verified by synthesizing 5d metal short-lived isotopes as homologous element isotopes of the light transactinide elements Sg, Bh, Hs, and Mt at the Japan Atomic Energy Agency tandem accelerator and conducting model experiments.
Yakushev, A.*; Lens, L.*; Dllmann, C. E.*; Block, M.*; Nagame, Yuichiro*; Sato, Tetsuya; Toyoshima, Atsushi*; 42 of others*
Frontiers in Chemistry (Internet), 9, p.753738_1 - 753738_9, 2021/11
Times Cited Count：10 Percentile：63.67(Chemistry, Multidisciplinary)Nihonium (Nh, element 113) and flerovium (Fl, element 114) are the first superheavy elements in which the 7p shell is occupied. High volatility and inertness were predicted for Fl due to the strong relativistic stabilization of the closed 7p
sub-shell, which originates from a large spin-orbit splitting between the 7p and 7p
orbitals. One unpaired electron in the outermost 7p sub-shell in Nh is expected to give rise to a higher chemical reactivity. Theoretical predictions of Nh reactivity are discussed, along with results of the first experimental attempts to study Nh chemistry in the gas phase. The experimental observations verify a higher chemical reactivity of Nh atoms compared to its neighbor Fl and call for the development of advanced setups. First tests of a newly developed detection device miniCOMPACT with highly reactive Fr isotopes assure that effective chemical studies of Nh are within reach.
Chiera, N. M.*; Sato, Tetsuya; Eichler, R.*; Tomitsuka, Tomohiro; Asai, Masato; Adachi, Sadia*; Dressler, R.*; Hirose, Kentaro; Inoue, Hiroki*; Ito, Yuta; et al.
Angewandte Chemie; International Edition, 60(33), p.17871 - 17874, 2021/08
Times Cited Count：2 Percentile：14.88(Chemistry, Multidisciplinary)The formation and the chemical characterization of single atoms of dubnium (Db, element 105), in the form of its volatile oxychloride, was investigated using the on-line gas phase chromatography technique, in the temperature range 350 - 600 
C. Under the exact same chemical conditions, comparative studies with the lighter homologs of group-5 in the Periodic Table clearly indicate the volatility sequence being NbOCl
TaOCl
DbOCl. From the obtained experimental results, thermochemical data for DbOCl were derived. The present study delivers reliable experimental information for theoretical calculations on the chemical properties of transactinides.
and CrGeTeIto, Naohiro*; Kikkawa, Takashi*; Barker, J.*; Hirobe, Daichi*; Shiomi, Yuki*; Saito, Eiji
Physical Review B, 100(6), p.060402_1 - 060402_6, 2019/08
Times Cited Count：43 Percentile：88.83(Materials Science, Multidisciplinary)Chiera, N. M.; Sato, Tetsuya; Tomitsuka, Tomohiro; Asai, Masato; Ito, Yuta; Shirai, Kaori*; Suzuki, Hayato; Tokoi, Katsuyuki; Toyoshima, Atsushi; Tsukada, Kazuaki; et al.
Journal of Radioanalytical and Nuclear Chemistry, 320(3), p.633 - 642, 2019/06
Times Cited Count：1 Percentile：11.15(Chemistry, Analytical)An isothermal gas-chromatographic (IGC) device has been developed and tested for on-line gas phase studies of volatile oxychlorides of short-lived group-5 transition metals. Radioisotopes of niobium and tantalum, produced in nuclear fusion evaporation reactions, are directly flushed into the IGC setup by an inert gas-jet. Oxychloride compounds are formed by the addition of SOCl
and O. Parameters influencing the formation and transport of NbOCl and TaOCl are investigated. For nuclides with half-lives (
) of about 30 s, an overall efficiency of 7% is obtained, rendering the IGC setup suitable for the chemical exploration of 
Db( = 34s).
BFujimoto, Tatsuya; Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Walstedt, R. E.; Ikeda, Shugo; Matsuda, Tatsuma; Haga, Yoshinori; Onuki, Yoshichika
Journal of the Physical Society of Japan, 75(Suppl.), p.113 - 115, 2006/08
The low-dimensional systems exhibit wide-variety of physical properties. In the antiferromagnetic triangular lattice, for instance, resonating valence bond state is expected, furthermore, in one-dimensional (1D) systems, metal-insulator transition (Peierls transition) occurs due to charge-lattice couplings. Up to now, the study of low-dimensional systems has been mostly performed in oxides and organic compounds, but it is rare in the rare-earth and actinide intermetallics. To looking for the novel low-dimensionality in 
-electron systems, we focused on the UIrB, and NMR measurement was carried out. From Knight shift and nuclear spin-lattice relaxation rates, ferromagnetic correlations develop above 50 K, but below 50 K, the emergence of antiferromagnetic correlations was clarified along with the saturation of ferromagnetic correlations. The possible model to explain the obtained result is nesting effect on the 1D Fermi surface, and it is expected that UIrB will be the typical compound to investigate the physical properties of 1D -electrons systems.
Nagame, Yuichiro
Radioisotopes, 54(11), p.555 - 567, 2005/11
no abstracts in English
Iwai, Yasunori; Yamanishi, Toshihiko; Nishi, Masataka; Suzuki, Yutaka*; Kurita, Koichi*; Shimazaki, Masanori*
Journal of Nuclear Science and Technology, 42(6), p.566 - 572, 2005/06
Times Cited Count：6 Percentile：40.47(Nuclear Science & Technology)Pressure swing adsorption has been studied as a new water processing method for a future fusion power plant which will have a large amount of tritiated water to be processed. A series of adsorption and dehydration experiments was carried out for a typical adsorbent of NaX zeolite and it was clearly observed that break through time differs in HO and HTO, that is, it is certain that NaX zeolite can separate into the tritium concentrated water and the tritium reduced water. The quick dehydration is attained by decompression and purge gas flowing. It was observed that a part of the water released by decompression was transferred by the purge gas, and the rest water was adsorbed on the adsorbent again and was gradually released by the diffusion. It is demonstrated that enlargement of pressure difference between adsorption and dehydration is effective to obtain high dehydration ratio. Furthermore, it was also verified that enough vapor removal capacity of purge gas is quite necessary to obtain high dehydration ratio.
Igawa, Naoki; Taguchi, Tomitsugu; Nozawa, Takashi*; Snead, L. L.*; Hinoki, Tatsuya*; McLaughlin, J. C.*; Kato, Yutai*; Jitsukawa, Shiro; Koyama, Akira*
Journal of Physics and Chemistry of Solids, 66(2-4), p.551 - 554, 2005/02
Times Cited Count：47 Percentile：82.48(Chemistry, Multidisciplinary)Silicon carbide is an important engineering ceramic because of its high strength and stability at high temperature and low induced radioactivity after neutron irradiation. Though monolithic SiC is brittle and low toughness, SiC fiber reinforced SiC matrix composites significantly improve these properties and therefore are attractive candidate materials for fusion reactor structural applications. Recently, stoichiometric SiC fibers with superior mechanical properties have been produced. We carried out the optimization of interface and composite fabrication using the chemical vapor infiltration, which is the one of the best techniques to fabricate the SiC composite. The composite with higher density and homogeneous matrix was obtained by the optimization of materials and carrier gas flow rate. The porosity was decreased with increasing the fiber volume fraction. We adopted the carbon or carbon/SiC interface between fiber and matrix and we found that the dependence of interface thickness on the tensile properties was small in the interface thickness from 50 to 300 nm.
Haba, Hiromitsu*; Nagame, Yuichiro
Gendai Kagaku, (405), p.32 - 38, 2004/12
no abstracts in English
Nakamura, Akio
Nihon Genshiryoku Gakkai-Shi, 45(11), p.736 - 737, 2003/11
no abstracts in English
Kaneko, Tetsuya*; Ono, Sawako*; Goto, Shinichi*; Haba, Hiromitsu; Asai, Masato; Tsukada, Kazuaki; Nagame, Yuichiro; Kudo, Hisaaki*
Journal of Radioanalytical and Nuclear Chemistry, 255(2), p.381 - 384, 2003/02
Times Cited Count：0 Percentile：0.01(Chemistry, Analytical)no abstracts in English
Hannan, A.*; Osakabe, Toyotaka; Kogi, Masafumi*; Iwasa, Kazuaki*
Applied Physics A, 74(Suppl.1), p.S565 - S567, 2002/12
Times Cited Count：6 Percentile：28.33(Materials Science, Multidisciplinary)no abstracts in English
phase diagram and magnetic structures of CeSbOsakabe, Toyotaka; Hannan, A.*; Tachi, N.*; Kogi, Masafumi*; Kitazawa, Hideaki*
Applied Physics A, 74(Suppl.1), p.S799 - S801, 2002/12
Times Cited Count：6 Percentile：28.33(Materials Science, Multidisciplinary)no abstracts in English
GeAbe, Hideki*; Yoshii, Kenji; Kitazawa, Hideaki*
Physica B; Condensed Matter, 312-313, p.253 - 255, 2002/03
Times Cited Count：4 Percentile：26.13(Physics, Condensed Matter)no abstracts in English
CuO
single crystalsZhukov, A. A.*; de Groot, P. A. J.*; Kokkaliaris, S.*; Di Nicolo, E.*; Jansen, A. G. M.*; Mossang, E.*; Martinez, G.*; Wyder, P.*; Wolf, T.*; Kpfer, H.*; et al.
Physical Review Letters, 87(1), p.017006_1 - 017006_4, 2001/07
Times Cited Count：13 Percentile：60.19(Physics, Multidisciplinary)no abstracts in English
