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Au(111)Oka, Kohei*; Tsuda, Yasutaka*; Makino, Takamasa*; Okada, Michio*; Hashinokuchi, Michihiro*; Yoshigoe, Akitaka; Teraoka, Yuden; Kasai, Hideaki*
Physical Chemistry Chemical Physics, 16(36), p.19702 - 19711, 2014/08
Times Cited Count：13 Percentile：41.41(Chemistry, Physical)Au(111) oxidation; Oxygen induced Cu segregation and the protective Au layer profileTsuda, Yasutaka*; Oka, Kohei*; Makino, Takamasa*; Okada, Michio*; Di
o, W. A.*; Hashinokuchi, Michihiro*; Yoshigoe, Akitaka; Teraoka, Yuden; Kasai, Hideaki*
Physical Chemistry Chemical Physics, 16(8), p.3815 - 3822, 2014/02
Times Cited Count：17 Percentile：51.21(Chemistry, Physical)
O formation on CuAu(110) surface with energetic O molecular beamsHashinokuchi, Michihiro*; Yoshigoe, Akitaka; Teraoka, Yuden; Okada, Michio*
Applied Surface Science, 287, p.282 - 286, 2013/12
Times Cited Count：6 Percentile：26.54(Chemistry, Physical)Hashinokuchi, Michihiro*; Tode, Mayumi*; Yoshigoe, Akitaka; Teraoka, Yuden; Okada, Michio*
Applied Surface Science, 276, p.276 - 283, 2013/07
Times Cited Count：5 Percentile：22.66(Chemistry, Physical)O formation on a Cu(110) surface with an energetic O molecular beamHashinokuchi, Michihiro*; Yoshigoe, Akitaka; Teraoka, Yuden; Okada, Michio*
Journal of Physics; Condensed Matter, 24(39), p.395007_1 - 395007_8, 2012/10
Times Cited Count：7 Percentile：29.38(Physics, Condensed Matter)Hashinokuchi, Michihiro*; Sumimoto, Yuichi*; Tode, Mayumi; Harries, J.; Okada, Michio*; Teraoka, Yuden; Kasai, Toshio*
Denki Gakkai Rombunshi, C, 130(10), p.1723 - 1729, 2010/10
The oxidation processes on a TiAl surface induced by a hyperthermal O molecular beam (HOMB) with a translational energy of 2.2 eV was studied by X-ray photoemission spectroscopy in conjunction with synchrotron radiation. At a surface temperature of 300 K, the simultaneous growth of Al and Ti oxides accompanied with the segregation of AlO near the surface was observed. The efficiency of oxidation for the HOMB incidence was smaller than that for O backfilling (25 meV). Furthermore, the chemical compositions of oxide species (AlO, TiO, TiO) on the TiAl surface were independent of the translational energy of incident O molecule. The present results suggest that the oxidation on TiAl surface proceeds via precursor molecular states.
Hashinokuchi, Michihiro*; Okada, Michio*; Ito, Hironori*; Kasai, Toshio*; Moritani, Kosuke*; Teraoka, Yuden
Physical Review Letters, 100(25), p.256104_1 - 256104_4, 2008/06
Times Cited Count：17 Percentile：65.37(Physics, Multidisciplinary)We report results of studies on surface-temperature dependence of steric effects in dissociative adsorption processes of NO molecules on Si(111)-(7
7) surface by means of X-ray photoemission spectroscopy. Data presented here show that the reactive sticking probability for N-end collisions is larger than that in O-end collisions at an incident energy of 58 meV. Furthermore, this steric preference is quite sensitive to the surface temperature and the surface coverage. These facts reveal that transient surface trapping of NO molecules in a shallow precursor state plays a key role in the initial step of the NO decomposition on the Si(111)-(77) surface.
Okada, Michio*; Hashinokuchi, Michihiro*; Moritani, Kosuke*; Kasai, Toshio*; Teraoka, Yuden
Japanese Journal of Applied Physics, 47(5), p.3686 - 3691, 2008/05
Times Cited Count：5 Percentile：21.57(Physics, Applied)An oriented-molecular-beam technique based on the Stark effect of a molecule in an inhomogeneous hexapole electrostatic field is a potential tool for stereochemical control of surface reactions. This technique allows us to select a specific rotational quantum state and also an orientation of a reagent molecule. We have developed a new UHV-compatible oriented-molecular-beam machine. This apparatus is equipped with components for X-ray photoemission spectroscopy (XPS) in order to detect surface-reaction products. In the dissociative adsorption of NO on an Si(111) surface, we found a steric effect in the reactivity by monitoring the products on the surface with the new machine. The N-end collision is more reactive than the O-end collision at an incident energy of 58 meV. To our knowledge, this is the first measurement of the steric effect appearing in the reaction products on the surface.
7) surfaceHashinokuchi, Michihiro*; Ito, Hironori*; Teraoka, Yuden; Moritani, Kosuke*; Okada, Michio*; Kasai, Toshio*
Japanese Journal of Applied Physics, 47(3), p.1672 - 1676, 2008/03
Times Cited Count：5 Percentile：21.57(Physics, Applied)Dissociative adsorption of nitric oxide (NO) on Si(111)-77 surface between 330-600 K was investigated using X-ray photoelectron spectroscopy. The uptake curves of both N and O atoms as a function of NO dose revealed a prominent temperature dependence of dissociative adsorption of NO on an Si(111)-77 surface. The decrease in the rates of dissociative adsorption of NO with increasing surface temperature suggested existence of a precursor state. Additionally, the N/O ratio on the surface changed from 1.0 at 330 K to 1.2 at 600 K. This increasing N/O ratio with increasing surface temperature suggests that an additional reaction path opens at higher surface temperature.
Au(100) using hyperthermal O molecular beamOkada, Michio*; Hashinokuchi, Michihiro*; Fukuoka, Masayuki*; Kasai, Toshio*; Moritani, Kosuke*; Teraoka, Yuden
Applied Physics Letters, 89(20), p.201912_1 - 201912_3, 2006/11
Times Cited Count：26 Percentile：64.27(Physics, Applied)Oxidation of CuAu(100) using a hyperthermal O molecular beam (HOMB) was investigated by X-ray photoemission spectroscopy in conjunction with a synchrotron light source. From the incident energy dependence of the O-uptake curve, it was determined that the dissociative adsorption of O implies a higher activation barrier and therefore less reactivity due to the Au alloying. The dissociative adsorption progresses with the Cu segregation on the surface. No prominent growth of CuO even for 2 eV HOMB suggests that the Au-alloying of Cu can serve as a protective layer against further oxidation into the bulk.
CN selected using hexapole electric field (Cooperative research)Hashinokuchi, Michihiro*; Okada, Michio*; Kasai, Toshio*; Moritani, Kosuke; Teraoka, Yuden
JAEA-Research 2005-002, 16 Pages, 2006/01
JAEA-Research-2005-002.pdf:0.91MB
The dynamical processes such as the energy transfer of a molecule to a surface, etc. play an important role in surface chemical reactions. An oriented-molecular-beam method can provide a great insight into these processes. We have developed a UHV-compatible oriented-molecular-beam machine. In the present study, we performed rotational-state selection of CHCN using hexapole electric field. We measured the focusing curve of CHCN, which was reproduced by the trajectory simulation including the second-order Stark effect in the inhomogeneous hexapole electric field. The expected orientation distributions suggest our ability to control the molecular orientation in surface reactions.
Watanabe, Daisuke*; Che, D.-C.*; Fukuyama, Tetsuya*; Hashinokuchi, Michihiro*; Teraoka, Yuden; Kasai, Toshio*
Review of Scientific Instruments, 76(5), p.055108_1 - 055108_5, 2005/05
Times Cited Count：6 Percentile：32.30(Instruments & Instrumentation)A molecular beam technique for generating an intense pulsed hyperthermal molecular beam (HTMB) was developed. The beam source consists of a pulse valve, a cooling-water bottle that protectes the pulse valve from heat transfer of a high temperature nozzle, and the nozzle with a heater. The pulsed HTMB of HCl was practically generated and characterized by means of (2+1) resonance-enhanced multiphoton ionization and ion time-of-flight techniques.
Hashinokuchi, Michihiro*; Sumimoto, Yuichi; Tode, Mayumi; Harries, J.; Okada, Michio*; Teraoka, Yuden; Kasai, Toshio*
no journal, ,
Titanium-based intermetallic alloys have attracted great attention as hydrogen storage materials. However, the oxide layer formed on the surface, which reduces the initial activation, has come to an issue. Therefore, improvements on the composition and structure in oxide layer are required. In this study, we investigated the oxidation on TiAl intermetallic alloys by hyperthermal Oxygen molecular beam (HOMB) and X-ray photoemission spectroscopy in conjunction with synchrotron radiation (SR-XPS).
Hashinokuchi, Michihiro*; Sumimoto, Yuichi*; Tode, Mayumi; Okada, Michio*; Harries, J.; Teraoka, Yuden; Kasai, Toshio*
no journal, ,
The oxidation processes on a TiAl surface induced by a hyperthermal O molecular beam (HOMB) with a translational energy of 2.2 eV was studied by X-ray photoemission spectroscopy in conjunction with synchrotron radiation. At a surface temperature of 300 K, the simultaneous growth of Al and Ti oxides accompanied with the segregation of AlO near the surface was observed. The efficiency of oxidation for the HOMB incidence was smaller than that for O backfilling (25 meV). Furthermore, the chemical compositions of oxide species (AlO, TiO, TiO) on the TiAl surface were independent on the translational energy of incident O molecules. The present results suggest that the oxidation on a TiAl surface proceed via molecular adsorption as a precursor state.
Hashinokuchi, Michihiro*; Okada, Michio*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
no abstracts in English
Au(110) surfaceHashinokuchi, Michihiro*; Tsuda, Yasutaka*; Makino, Takamasa*; Okada, Michio*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
no abstracts in English
Au(111) oxidationTsuda, Yasutaka*; Makino, Takamasa*; Hashinokuchi, Michihiro*; Okada, Michio*; Oka, Kohei*; Dio, W. A.*; Kasai, Hideaki*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Okada, Michio*; Goto, Seishiro*; Hashinokuchi, Michihiro*; Moritani, Kosuke*; Teraoka, Yuden; Kasai, Toshio*
no journal, ,
We have been developing a new machine of ultra-high-vacuum compatible oriented-molecular beam apparatus. We report results of a study on the incident-energy and the surface-temperature dependence of the steric effects in the dissociative adsorption of CHCl on an Si(100) surface. The initial sticking probability was measured by the King-Wells method. The data show that the initial sticking probability for the Cl-end collision is larger at an incident energy of 120 meV than that in the CH-end collision. Furthermore, this steric preference is quite sensitive to the kinetic energy and the rotational state and the surface temperature. This study shows that the non-equilibrium surface trapping plays a key role in the initial step of the decomposition. We also introduce the on-going experiments using a new apparatus for the reaction of oriented NO molecules with Si(111), we found that a N-end collision is more effective for the reaction than O-end collision.
Hashinokuchi, Michihiro*; Okada, Michio*; Ito, Hironori*; Kasai, Toshio*; Moritani, Kosuke*; Teraoka, Yuden
no journal, ,
We present the steric effect recently observed in the dissociative adsorption of NO on Si(111)-77 surface by using an oriented-molecular-beam apparatus especially designed for X-ray photoelectron spectroscopy. The (1/2,1/2,1/2) state-selected NO molecular beam with the kinetic energy of 58 meV was incident to Si(111) surface and adsorbed species were analyzed by XPS. We find that the reaction is more favorable for the N-end than that for the O-end. The steric preference becomes very small at 600K. This result shows that transient trapping into a shallow precursor state plays the key role in the stereodynamics of this surface reaction.
Kasai, Toshio*; Hashinokuchi, Michihiro*; Okada, Michio*; Ito, Hironori*; Moritani, Kosuke*; Teraoka, Yuden
no journal, ,
It is very important to study on steric effects or orientational effects of inpinging molecules to understand chemical reactions with an atomic and molecular level. Recently, orientational effects of NO molecules for dissociative adsorption at Si(111)-77 surface has been observed by a surface analytical method using X-ray photoemission spectroscopy. Chemical reactivity of N-end collisions was larger than that of O-end collisions. It depended on surface temperature. It was concluded that NO molecules were trapped tentatively on the Si(111) surface.
