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Ueta, Hirokazu; Fukutani, Katsuyuki*; Yamakawa, Koichiro
Frontiers in Chemistry (Internet), 11, p.1258035_1 - 1258035_7, 2023/08
Times Cited Count：0 Percentile：0.01(Chemistry, Multidisciplinary)Molecular hydrogen has two nuclear-spin modifications called 
and 
. Because of the symmetry restriction with respect to permutation of the two protons, the and isomers take only odd and even values of the rotational quantum number, respectively. The -to- conversion is promoted in condensed systems, to which the excess rotational energy and spin angular momentum are transferred. We review recent studies on fast -to- conversion of hydrogen in molecular chemisorption and matrix isolation systems, discussing the conversion mechanism as well as rotational-relaxation pathways.
ortho-para conversion on a metal surface; Interplay between electron and phonon systemsUeta, Hirokazu; Fukutani, Katsuyuki
Journal of Physical Chemistry Letters (Internet), 14(34), p.7591 - 7596, 2023/08
Tsuda, Yasutaka; Gueriba, J. S.*; Ueta, Hirokazu*; Di
o, W. A.*; Kurahashi, Mitsunori*; Okada, Michio*
JACS Au (Internet), 2(8), p.1839 - 1847, 2022/08
Nagaya, Yuki*; Nakatsu, Hiroki*; Ogura, Shohei*; Shimazaki, Kota*; Ueta, Hirokazu; Takeyasu, Kotaro*; Fukutani, Katsuyuki
Journal of Chemical Physics, 155(19), p.194201_1 - 194201_6, 2021/11
Times Cited Count：0 Percentile：0.01(Chemistry, Physical) on Pd(210)Ueta, Hirokazu; Fukutani, Katsuyuki
Vacuum and Surface Science, 64(9), p.430 - 434, 2021/09
on Pd(210)Ueta, Hirokazu; Sasakawa, Yuya*; Ivanov, D.*; Ono, Satoshi*; Ogura, Shohei*; Fukutani, Katsuyuki
Physical Review B, 102(12), p.121407_1 - 121407_5, 2020/09
Times Cited Count：1 Percentile：6.04(Materials Science, Multidisciplinary)Ortho-to-para conversion of molecularly chemisorbed H on a Pd(210) surface at a surface temperature of 50 K is reported. A combination of a pulsed molecular beam, photo-stimulated desorption and resonance-enhanced multiphoton ionization techniques was used for probing the change in the rotational states of molecularly chemisorbed H on the surface. Our result shows that fast ortho-para conversion of chemisorbed H occurs. The conversion time was experimentally determined to be about 2 s, which is in good agreement with a previous theoretical calculation. This agreement supports that the ortho-para conversion mechanism of the molecularly chemisorbed H on Pd(210) is the two-step process based on the hyperfine-Coulomb excitation.
Shiina, Yoko*; Takaya, Kazunari*; Ueta, Hirokazu; Hirayama, Takato*; Nakano, Yuji*
Journal of Physics; Conference Series, 1412, P. 122021_1, 2020/06
Times Cited Count：0 Percentile：0.16(Optics) on Pd(210)Ueta, Hirokazu; Sasakawa, Yuya*; Ivanov, D.*; Ono, Satoshi*; Fukutani, Katsuyuki
no journal, ,
on Pd(210)Ueta, Hirokazu; Sasakawa, Yuya*; Ivanov, D.*; Ono, Satoshi*; Ogura, Shohei*; Fukutani, Katsuyuki
no journal, ,
on Pd(210)Ueta, Hirokazu; Sasakawa, Yuya*; Ivanov, D.*; Ono, Satoshi*; Fukutani, Katsuyuki
no journal, ,
While hydrogen typically chemisorbs dissociatively on a flat metal surface, it is known that hydrogen can molecularly chemisorb on stepped surfaces, such as Pd(210). In this study, using a combination of a pulsed molecular beam, photo-stimulated desorption and resonance-enhanced multiphoton ionization techniques, the rotational states of molecularly chemisorbed H are probed. We will present the rotational state distribution of photo-desorbed H, and the o-p conversion process of molecularly chemisorbed H will be discussed.
on Pd(210)Ueta, Hirokazu; Sasakawa, Yuya*; Ivanov, D.*; Ono, Satoshi*; Ogura, Shohei*; Fukutani, Katsuyuki
no journal, ,
Surface defects such as step and kink affect surfaced reaction. While hydrogen typically chemisorbs dissociatively on a flat metal surface, it is known that hydrogen can molecularly chemisorb on stepped surfaces, such as Pd(210). Recently, we developed a technique to probe ortho-para conversion of adsorbed hydrogen which consists of a combination of a pulsed molecular beam, photo-stimulated desorption and resonance-enhanced multiphoton ionization techniques. We report a result of orho-para conversion time of molecularly chemisorbed H on Pd(210).
on Pd(210)Ueta, Hirokazu; Sasakawa, Yuya*; Ivanov, D.*; Ono, Satoshi*; Ogura, Shohei*; Fukutani, Katsuyuki
no journal, ,
no abstracts in English
Ueta, Hirokazu
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no abstracts in English
ortho-para conversion on a stepped Pd surfaceUeta, Hirokazu; Sasakawa, Yuya*; Ivanov, D.*; Ono, Satoshi*; Ogura, Shohei*; Fukutani, Katsuyuki
no journal, ,
We present a direct measurement of fast Ortho-Para conversion of molecularly chemisorbed H on Pd(210) at a surface temperature of 50 K. The determined conversion time was about 2 sec, which is in reasonably agreement with a previous theoretical calculation. This agreement supports that ortho-para conversion mechanism of the molecularly chemisorbed H on Pd(210) is the two-step process based on the hyperfine-Coulomb excitation.
ortho-para conversionUeta, Hirokazu; Fukutani, Katsuyuki
no journal, ,
nuclear conversion on surfaceUeta, Hirokazu; Fukutani, Katsuyuki
no journal, ,
no abstracts in English
on Pd(210)Ueta, Hirokazu; Fukutani, Katsuyuki
no journal, ,
Ueta, Hirokazu; Fukutani, Katsuyuki
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Ueta, Hirokazu; Ohashi, Yusei*; Ishizaki, Yuji*; Sun, Z.-D.*; Ozawa, Takahiro*; Fukutani, Katsuyuki
no journal, ,
no abstracts in English
Tsuda, Yasutaka; Gueriba, J. S.*; Ueta, Hirokazu; Dio, W. A.*; Kurahashi, Mitsunori*; Okada, Michio*
no journal, ,
