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Ishii, Kenji*; Toyama, Takami*; Asano, Shun*; Sato, Kentaro*; Fujita, Masaki*; Wakimoto, Shuichi; Tsutsui, Kenji*; Sota, Shigetoshi*; Miyawaki, Jun*; Niwa, Hideharu*; et al.
Physical Review B, 96(11), p.115148_1 - 115148_8, 2017/09
Times Cited Count:29 Percentile:77.9(Materials Science, Multidisciplinary)Kim, S.-Y.; Takao, Koichiro*; Haga, Yoshinori; Yamamoto, Etsuji; Kawata, Yoshihisa; Morita, Yasuji; Nishimura, Kenji*; Ikeda, Yasuhisa*
Crystal Growth & Design, 10(5), p.2033 - 2036, 2010/04
Times Cited Count:15 Percentile:77.61(Chemistry, Multidisciplinary)Plutonyl(VI) nitrate complexes with N-cyclohexyl-2-pyrrolidone (NCP) and N-neopentyl-2-pyrrolidone (NNpP) were prepared, and their molecular and crystal structures were determined by single crystal X-ray analysis. The obtained compounds have the similar composition, PuO(NO)(NRP) (NRP = NCP, NNpP), which are analogous to the corresponding U(VI) complexes. Both PuO(NO)(NRP) complexes show typical structural properties of actinyl(VI) nitrates, i.e., hexagonal-bipyramidal geometry consisting of two NRP molecules and two NO ions located in trans positions in the equatorial plane of PuO moiety. These findings provide one of criteria in selection of suitable NRP as a precipitation agent for the spent nuclear fuel reprocessing based on the precipitation method.
Ishida, Natsuko*; Ota, Yukihiro; Yamamoto, Yoshihisa*
New Journal of Physics (Internet), 11, p.033007_1 - 033007_15, 2009/03
Times Cited Count:1 Percentile:10.99(Physics, Multidisciplinary)We propose a scheme to generate a novel state, a multi-path cat state of light, in which photons are propagating in different paths. Starting with indistinguishable single-photon sources and using linear optical circuits, the target state is extracted with high fidelity. If a state preserving quantum non-demolition measurement of photon number can be incorporated into the generation scheme, the fidelity is further improved.
Suemitsu, Maki*; Yamamoto, Yoshihisa*; Togashi, Hideaki*; Enta, Yoshiharu*; Yoshigoe, Akitaka; Teraoka, Yuden
Journal of Vacuum Science and Technology B, 27(1), p.547 - 550, 2009/02
Times Cited Count:4 Percentile:29.68(Engineering, Electrical & Electronic)Initial oxidation processes of the Si(110) surface and the chemical bonding states of silicon atoms in the initial oxides have been investigated by using real-time synchrotron-radiation photoemission spectroscopy. Time evolutions of the Si (=1-4) components in the Si 2 spectrum indicates that the Si component always overwhelms the Si component during the oxidation up to one monolayer. This is in sharp contrast to the Si(001) surface where Si is always larger than Si. The dominance of the Si component is related to presence of two types of bonds on the Si(110) surface and to their possible different reactivity against insertion of oxygen atoms.
Yamamoto, Yoshihisa*; Suzuki, Yasushi*; Miyamoto, Yu*; Bantaculo, R.*; Suemitsu, Maki*; Enta, Yoshiharu*; Teraoka, Yuden; Yoshigoe, Akitaka; Asaoka, Hidehito; Yamazaki, Tatsuya
Hakumaku, Hyomen Butsuri Bunkakai, Shirikon Tekunoroji Bunkakai Kyosai Tokubetsu Kenkyukai Kenkyu Hokoku, p.207 - 210, 2009/01
The bending of Si substrate has been measured optically in the oxidation of Si(110) surface and variation of curvature for (001) and (-110) directions have been evaluated. Furthermore, time evolutions of oxygen adsorption content and its chemical bonding states have been measured by photoemission spectroscopy to discuss inisotropy of the Si(110) oxidation in comjunction with substrate curvature measurements. Oxygen adsorption content was evaluated from O1s photoemission and chemical bonding states were evaluated from Si2p photoemission. O gas pressure was ranging from 5.010 Pa to 6.710 and substrate temperature was 873 K. Compressive stress was detected in the (-110) direction. In turn, stretching stress was detected. The photoemission spectroscopy indicated that a layer-by-layer oxidation was not took place. The stretching stress in the (001) direction implies that oxidation of B-bonds which have components along the (001) direction takes place.
Mori, Michiaki; Yogo, Akifumi; Kiriyama, Hiromitsu; Nishiuchi, Mamiko; Ogura, Koichi; Orimo, Satoshi; Ma, J.*; Sagisaka, Akito; Kanazawa, Shuhei; Kondo, Shuji; et al.
IEEE Transactions on Plasma Science, 36(4), p.1872 - 1877, 2008/08
Times Cited Count:7 Percentile:28.47(Physics, Fluids & Plasmas)A dependence of cut-off proton kinetic energy on laser prepulse duration has been observed. ASE pedestal duration is controlled by a fast electro-optic pulse slicer where the risetime is estimated to be 130 ps. We demonstrate a new correlated spectral technique for determining this risetime using a stretched, frequency chirped pulse.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Takahashi, Yuya*; Konno, Atsushi*; Teraoka, Yuden; Yoshigoe, Akitaka; Asaoka, Hidehito; Suemitsu, Maki*
Applied Surface Science, 254(19), p.6232 - 6234, 2008/07
Times Cited Count:4 Percentile:21.85(Chemistry, Physical)The room temperature adsorbed state of oxygen molecules on Si(110)-162 surface and the structural change after a mild annealing has been investigated by synchrotron radiation photoemission spectroscopy. As a result, despite the very small dosage of oxygen, Si and Si components already appear in addition to Si. This is likely to be caused by a selective adsorption of O molecules into the vicinity of already oxidized sites. After annealing, we found that binding energy of Si and Si increase and approach to their corresponding peak positions of a thermally-grown oxide, and this increase indicates relaxation of the Si-O bond length and Si-O-Si bond angle of metastable oxygen atoms.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Matsumoto, Mitsutaka*; Kato, Atsushi*; Saito, Eiji*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
Shingaku Giho, 108(80), p.65 - 70, 2008/06
The growth process of thermal oxides on Si(110) surface and the development of their interfacial bonding structures have been investigated by using real-time synchrotron radiation photoemission spectroscopy. As a result, it was clarified that the Si component in the Si 2p core-level spectra is always much higher than that of Si for 0-1 mono-layer (ML) oxides on Si(110) surface. Observations on the time-evolution of the O 1s core-level spectrum indicates that the autocatalytic-reaction model proposed for the Si(001) oxidation can be also applicable to the Si(110) oxidation.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Suemitsu, Maki*; Narita, Yuzuru*; Teraoka, Yuden; Yoshigoe, Akitaka
Materials Research Society Symposium Proceedings, Vol.1074, p.36 - 40, 2008/00
In this study, we have investigated the bonding structure of ultrathin oxide films on Si(110) surface by real-time SR-PES experiments. Experiments were conducted at surface chemistry end-station settled at BL23SU in SPring-8. The oxidation temperature was 813 K and the O pressure was 1.110 Pa. As a result, we found that one of the surface core-level shifts in Si 2p spectrum, related to the 1st and the 2nd layer Si atoms, decreases rapidly, coincident with the rapid initial development of the O1s spectrum. This indicates high reactivity of the Si(110)-162 reconstructed surface with oxygen molecules.
Orimo, Satoshi; Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Ogura, Koichi; Sagisaka, Akito; Li, Z.*; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; et al.
Japanese Journal of Applied Physics, Part 1, 46(9A), p.5853 - 5858, 2007/09
Times Cited Count:17 Percentile:54.99(Physics, Applied)A laser-driven proton beam with a maximum energy of a few MeV is stably obtained using an ultra-short and high-intensity Titanium Sapphire laser. At the same time, keV X-ray is also generated at almost the same place where protons are emitted. Here, we show the successful demonstration of simultaneous proton and X-ray projection images of a test sample placed close to the source with a resolution of 10m, which is determined from the source sizes. Although the experimental configuration is very simple, the simultaneity is better than a few hundreds of ps. A CR-39 track detector and imaging plate, which are placed as close as possible to the CR-39, are used as detectors of protons and X-ray. The technique is applicable to the precise observation of microstructures.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*; Enta, Yoshiharu*
Japanese Journal of Applied Physics, Part 1, 46(4B), p.1888 - 1890, 2007/04
Times Cited Count:12 Percentile:44.48(Physics, Applied)Initial oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy. The time evolution of the O 1s spectrum shows occurrence of rapid oxidation just after the introduction of the oxygen molecules, which is evidenced by the considerable peak intensity corresponding to oxygen exposure of as low as 1.5L (1L=1.3310 Pa s). This initial oxide is dominated by a state with a relatively low binding energy, which is gradually replaced by a state with a relatively high binding energy with the increase of the oxygen exposure, resulting in the low-KE shift of the O 1s peak. Comparison with previously reported O 1s spectra from dry-oxidized Si(111) surface suggests oxidation at or around the adatoms of Si(110)-162 clean surface as a likely oxidation state for this low-binding-energy peak.
Suemitsu, Maki*; Togashi, Hideaki*; Kato, Atsushi*; Takahashi, Yuya*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Asaoka, Hidehito
Materials Research Society Symposium Proceedings, Vol.996, p.19 - 25, 2007/00
From its high hole mobility, as well as its inevitable usage as an active layer in multi-gated FETs, Si(110) surface is expected to play a crucial role in the next generation CMOS devices. We have investigated the initial oxidation of Si(110) surface by using SR-XPS and STM. Reflecting its atomistic structure of the 162 reconstruction, initial oxidation of Si(110) surface shows a unique behavior which is not observed on other surfaces like (111) and (001).
Daido, Hiroyuki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Mori, Michiaki; Ma, J.-L.; Pirozhkov, A. S.; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.
Proceedings of 7th Pacific Rim Conference on Lasers and Electro-Optics (CLEO-PR 2007) (CD-ROM), p.77 - 79, 2007/00
We are developing a proton accelerator using an intense lasers with a focused intensity of 10 W/cm. To monitor proton energy spectra as well as plasma parameters at each laser shot, we are using real time detectors. The proton energy of MeV is stably obtained for applications.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
Shingaku Giho, 106(108), p.61 - 63, 2006/06
no abstracts in English
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Enta, Yoshiharu*; Narita, Yuzuru*
ECS Transactions, 3(2), p.311 - 316, 2006/00
Initial thermal oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy with synchrotron radiation. The Si(110) initial oxidation is characterized by presence of a rapid oxidation just after the introduction of gaseous oxygen molecules. Peak separation of the O1s photoemission spectra suggests the presence of at least two distinct oxidation sites on the surface, which may reflect the complicated surface structure of the Si(110)-162 reconstruction.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
Initial kinetics in dry oxidation of Si(110) surface, a key technology in the next-generation CMOS technology, has been investigated by using synchrotron-radiation photoemission spectroscopy. As a result, the uptake curve of the Si(110) oxide in its high-pressure-low-temperature reaction regime is found to consist of three characteristic time domains, in sharp contrast with the single domain obtained on Si(001). The difference is understood in terms of the different atomistic arrangement on the surface.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
By using real-time photoemission spectroscopy, kinetics of initial oxidation of Si(110)-162 surface has been investigated and is compared with that of Si(100) surface. Dry oxidation of Si(110) shows rapid initial oxidation just after introduction of the oxygen, which is associated with an O1s state with a weaker binding energy. As the oxidation proceeds, another O1s state with a stronger binding energy develops. The rapid initial oxidation is related to oxidation at or around the Si(111)-like Si adatoms, which are reportedly present in the 162 reconstruction of the Si(110) surface.
Togashi, Hideaki*; Kato, Atsushi*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
Initial oxidation processes of Si(110) surface have not been studied although they are important for the next generation device. Now we observed time evolution of oxygen coverage at the Si(110)-162 surface in the initial oxidation region by using real-time photoemission spectroscopy with synchrotron radiation. As a conclusion, rapid initial oxidation processes, in which several tens per cent of the surface was oxidized just after oxygen exposure, were found in experimental conditions of 813 K and oxygen pressure of 1.110 Pa. Such a rapid initial oxidation process has not been observed in the initial oxidation of Si(100)-21 surface. This phenomenon may be related with adatom clusters, which exist periodically on the Si(110)-162 surface. For example, An adatom cluster, which consists of five Si atoms, shares 0.25 ML on the Si(110)-162 reconstruction surface in the pentagon-pair model. This model consistents with the initial oxygen coverage obtained in this experiment.
Kato, Atsushi*; Togashi, Hideaki*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Initial oxidation processes of ultra-thin oxide layers on Si(110)-162 surfaces have not been studied yet. Making clear the chemical reaction mechanisms is, however, important for device fabrication. We observed time evolution of oxide coverage on the Si(110)-162 surface at room temperature. The O1s photoemission spectrum increased with increasing oxygen dose and the peak position shifted to higher binding energy side at oxygen pressure of 1.110 Pa. This peak shift is responsible to two kinds of peak components and their independent time evolutions. Time evolution of each component, behaviour of Si2p spectrum, and thermal stability of the surface reveal that the oxidation of Si(110) surface has different characters in compared with that of Si(100) surface. These facts can be understood on the basis of adatom clusters on the Si(110) surface.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
no abstracts in English