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Yoshida, Masahiro*; Ishii, Kenji; Jarrige, I.*; Watanuki, Tetsu; Kudo, Kazutaka*; Koike, Yoji*; Kumagai, Kenichi*; Hiraoka, Nozomu*; Ishii, Hirofumi*; Tsuei, K.-D.*; et al.
Journal of Synchrotron Radiation, 21(1), p.131 - 135, 2014/01
Times Cited Count:3 Percentile:19.11(Instruments & Instrumentation)Shimizu, Yuta*; Inagaki, Makoto*; Kumada, Takayuki; Kumagai, Jun*
Journal of Chemical Physics, 132(24), p.244503_1 - 244503_8, 2010/06
Times Cited Count:0 Percentile:0.01(Chemistry, Physical)We performed electron spin resonance studies of trapped electrons and H radical cations produced by radiolysis of solid para-H, para-H-ortho-D, and para-H-HD mixtures. Yields of both trapped electrons, and H radical cations, and its isotopic analogues increased with increasing the concentration of ortho-D and HD concentrations in solid para-H. We have concluded that electrons were found trapped nearby an ortho-D or an HD in solid para-H due to a the long-range charge-induced dipole and charge-induced quadrupole interactions between an electrons and an isotopic hydrogen molecules.
Kumada, Takayuki; Ushida, Takahiro*; Shimizu, Yuta*; Kumagai, Jun*
Radiation Physics and Chemistry, 77(10-12), p.1318 - 1322, 2008/10
Times Cited Count:8 Percentile:49.21(Chemistry, Physical)Very recently, we succeeded in observing totally more than 50 sharp ESR lines of H and its isotope substituents HD, HD, and HD in -ray irradiated solid para-H (p-H) and p-H-D and p-H-HD mixtures. We also observed isotope-substitution reactions such as H + HD HD + H and H + D HD + H. The H ions diffuse in solid p-H via the repetition of H + H H + H reactions which terminate by the H + HD or H + D reactions. The HD, HD, and HD ions, on the other hand, are immobile in solid p-H. They decay via geminate recombination with trapped electrons within the time-scale of 5 hours.
Kurosaki, Yuzuru; Shimizu, Yuta*; Kumagai, Jun*
Chemical Physics Letters, 455(1-3), p.59 - 63, 2008/03
Times Cited Count:2 Percentile:5.23(Chemistry, Physical)Direct ab initio molecular dynamics calculations have been carried out for the H cluster and its isotopic analogues: [H(H)H], [H(H)D], and [H(HD)H]. The calculations predict that the average geometry over the trajectories becomes asymmetric in both the deuterated clusters [H(H)D] and [H(HD)H], causing disproportion in the spin density that determines hyperfine coupling constants (HFCCs). This prediction agrees well with a recent ESR study that observed the isotope effects on the HFCCs for the central H in these clusters generated in -irradiated solid -H. Thus the present result strongly supports the H cluster formation in the solid -H.
Kumagai, Jun*; Inagaki, Hiroki*; Kariya, Susumu*; Ushida, Takahiro*; Shimizu, Yuta*; Kumada, Takayuki
Journal of Chemical Physics, 127(2), p.024505_1 - 024505_13, 2007/07
We carried out an electron spin resonance (ESR) study on hydrogen ion radicals produced by radiolysis of solid parahydrogen. We newly observed totally more than fifty resolved lines in irradiated solid parahydrogens. We assigned these lines to be isotope substituents of H-core H ions such as HD, HD, and HD throughout comparison of their ESR parameters with theoretical results. These results show conclusive evidence that H-core H ions are produced and stably trapped in irradiated solid hydrogens. We also observed a lowering symmetry on electron wave function in HD and HD, and isotope-substitution reactions such as H+DHD+H and H+HDHD+H.
Kumagai, Jun*; Inagaki, Hiroshi*; Kariya, Susumu*; Ushida, Takahiro*; Shimizu, Yuta*; Kumada, Takayuki
Journal of Chemical Physics, 127(2), p.024505_1 - 024505_13, 2007/07
Times Cited Count:17 Percentile:51.97(Chemistry, Physical)We carried out an electron spin resonance (ESR) study on hydrogen ion radicals produced by radiolysis of solid parahydrogen. In addition to quartet ESR lines proposed to be H-core H ions in solid parahydrogen, we newly observed totally more than fifty resolved lines in -ray irradiated solid para-H-ortho-D (1 mol %) and para-H-HD (1 mol %) mixtures. We assigned these lines to be isotope substituents of H-core H ions such as HD, HD, and HD throughout comparison of their ESR parameters with theoretical results.
Ishii, Kenji; Tsutsui, Kenji*; Toyama, Takami*; Inami, Toshiya; Mizuki, Junichiro; Murakami, Yoichi*; Endo, Yasuo*; Maekawa, Sadamichi*; Kudo, Kazutaka*; Koike, Yoji*; et al.
Physical Review B, 76(4), p.045124_1 - 045124_7, 2007/07
Times Cited Count:20 Percentile:63.5(Materials Science, Multidisciplinary)(La,Sr,Ca)CuO is an attractive material in connection with high- superconductivity because SrCaCuO becomes a superconductor under high pressure without the CuO planes. We present RIXS at the Cu -edge of (La,Sr,Ca)CuO focusing on the momentum dependence of interband excitation across the Mott gap and the intraband excitation below the gap as a function of hole concentration. The experimental results are consistent with the theoretical predictions.
Kojima, Takuji; Hirade, Tetsuya; Kumagai, Jun*
Hoshasen Kagaku No Susume; Denshi, Ion, Hikari No Bimu Ga Kurashi O Kaeru, Sangyo O Tsukuru, p.1 - 23, 2006/02
no abstracts in English
Kojima, Takuji; Hirade, Tetsuya; Kumagai, Jun*
Hoshasen Kagaku No Susume; Denshi, Ion, Hikari No Bimu Ga Kurashi O Kaeru, Sangyo O Tsukuru, p.25 - 38, 2006/02
no abstracts in English
Kumada, Takayuki; Sakakibara, Masahiro*; Nagasaka, Toshimitsu*; Fukuta, Hiroya*; Kumagai, Jun*; Miyazaki, Tetsuo*
Journal of Chemical Physics, 116(3), p.1109 - 1119, 2002/01
Times Cited Count:43 Percentile:78.02(Chemistry, Physical)We have studied diffusion and recombination of H atoms in solid hydrogen using ESR, ENDOR, and ESE spectrometer. The rate constant for recombination of H atoms in highly purified parahydrogen was found to be much smaller than that expected by diffusion coefficient. This result indicates that the H atoms do not recombine in the absence of energy dispersion path in highly purified parahydrogen.
Kumada, Takayuki; Kumagai, Jun*; Miyazaki, Tetsuo*
Journal of Chemical Physics, 114(22), p.10024 - 10030, 2001/06
Times Cited Count:14 Percentile:41.33(Chemistry, Physical)no abstracts in English
Kumada, Takayuki; Noda, Tomoyoshi*; Kumagai, Jun*; Aratono, Yasuyuki; Miyazaki, Tetsuro
Journal of Chemical Physics, 111(24), p.10974 - 10978, 1999/12
Times Cited Count:10 Percentile:31.13(Chemistry, Physical)no abstracts in English
Kumada, Takayuki; *; *; Kumagai, Jun*; Aratono, Yasuyuki; Miyazaki, Tetsuro*
Journal of Low Temperature Physics, 114(5-6), p.413 - 429, 1999/00
no abstracts in English
Kumada, Takayuki; *; Kumagai, Jun*; Aratono, Yasuyuki; Miyazaki, Tetsuro*
Journal of Physical Chemistry A, 103(45), p.8966 - 8968, 1999/00
Times Cited Count:13 Percentile:39.04(Chemistry, Physical)no abstracts in English
Kumada, Takayuki; *; Noda, Tomoyoshi*; Kumagai, Jun*; Aratono, Yasuyuki; Miyazaki, Tetsuro*
Chemical Physics Letters, 288(5-6), p.755 - 759, 1998/00
Times Cited Count:27 Percentile:64.6(Chemistry, Physical)no abstracts in English
Ara, Hiroshige*; Fukumitsu, Kenji*; Iizuka, Yunosuke*; Ishii, Takashi*; Izumiya, Yasushi*; Imazu, Masanori*; Utsugida, Yoshizo*; Hasegawa, Makoto*; Maeda, Masaya*; Yabe, Yukio*; et al.
PNC TJ199 84-04VOL1, 20 Pages, 1984/03
None
Ishii, Kenji; Tsutsui, Kenji*; Toyama, Takami*; Mizuki, Junichiro; Endo, Yasuo; Maekawa, Sadamichi*; Kudo, Kazutaka*; Koike, Yoji*; Kumagai, Kenichi*
no journal, ,
(La,Sr,Ca)CuO is an attractive material in connection with high- superconductivity because SrCaCuO becomes a superconductor under high pressure without the CuO planes. We present RIXS at the Cu -edge of (La,Sr,Ca)CuO focusing on the momentum dependence of interband excitation across the Mott gap and the intraband excitation below the gap as a function of hole concentration. The experimental results are consistent with the theoretical predictions.
Ishii, Kenji; Tsutsui, Kenji*; Toyama, Takami*; Inami, Toshiya; Mizuki, Junichiro; Murakami, Yoichi*; Endo, Yasuo*; Maekawa, Sadamichi*; Kudo, Kazutaka*; Koike, Yoji*; et al.
no journal, ,
(La,Sr,Ca)CuO is an attractive material in connection with high- superconductivity because SrCaCuO becomes a superconductor under high pressure without the CuO planes. We present RIXS at the Cu -edge of (La,Sr,Ca)CuO focusing on the momentum dependence of interband excitation across the Mott gap and the intraband excitation below the gap as a function of hole concentration. The experimental results are consistent with the theoretical predictions.
Ishii, Kenji; Tsutsui, Kenji*; Toyama, Takami*; Inami, Toshiya; Mizuki, Junichiro; Murakami, Yoichi*; Endo, Yasuo*; Maekawa, Sadamichi*; Kudo, Kazutaka*; Koike, Yoji*; et al.
no journal, ,
(La,Sr,Ca)CuO is an attractive material in connection with high- superconductivity because SrCaCuO becomes a superconductor under high pressure without the CuO planes. We present RIXS at the Cu -edge of (La,Sr,Ca)CuO focusing on the momentum dependence of interband excitation across the Mott gap and the intraband excitation below the gap as a function of hole concentration. The experimental results are consistent with the theoretical predictions.
Ishii, Kenji; Tsutsui, Kenji*; Toyama, Takami*; Inami, Toshiya; Mizuki, Junichiro; Murakami, Yoichi*; Endo, Yasuo*; Maekawa, Sadamichi*; Kudo, Kazutaka*; Koike, Yoji*; et al.
no journal, ,
(La,Sr,Ca)CuO is an attractive material in connection with high- superconductivity because SrCaCuO becomes a superconductor under high pressure without the CuO planes. We present RIXS at the Cu -edge of (La,Sr,Ca)CuO focusing on the momentum dependence of interband excitation across the Mott gap and the intraband excitation below the gap as a function of hole concentration. The experimental results are consistent with the theoretical predictions.