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-rays and heavy-ion beam in 
Bolige, A.*; Sakashita, Tetsuya; Kakizaki, Takehiko*; Funayama, Tomoo; Hamada, Nobuyuki*; Wada, Seiichi*; Kobayashi, Yasuhiko; Goto, Ken*
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 117, 2008/03
We report here how these rhythms are related to each other. First, irradiation temperatures influenced neither survival after exposure to UV, rays, nor C ions, whereas the incubation at high temperatures (25 
C) after irradiation considerably lowered the survival particularly after irradiation, but not after UV irradiation at all. Secondly, although the antioxidants 
carotene and dimethylsulfoxide (DMSO) increased the survival of the alga at the least resistant phase after UV C and UV B irradiation, respectively, to the level of the most resistant alga, none of these were not so effective for or C ion irradiation. Finally, FITC dextran was incorporated into the alga only after C ion irradiation but not irradiation, suggesting that C ion may perforate cell membranes to kill the alga.
7 heteroepitaxial growthAsaoka, Hidehito; Yamazaki, Tatsuya; Shamoto, Shinichi; Arnoldo, A.*; Goto, Seiichi*; Suemitsu, Maki*
Hyomen Kagaku, 28(9), p.500 - 503, 2007/09
Stress evolution during initial stage of Ge nanodot formation on Si(111)-77 has been investigated by using simultaneous measurements of the substrate curvature and the surface morphology. In the beginning of the first bilayer growth of Ge on Si(111)-77, a strong compressive film stress is observed, indicating a formation of a two-dimensional wetting layer. When the layer thickness approaches the critical one for three-dimensional nanodot nucleation, a clear bend in the stress curve is observed, corresponding to a partial relaxation of the lattice planes on the surface of the nanodots. Moreover, a stress transition has been also found to exist in the very early stage of the nanodot formation, which is concurrent with the trench formation around the three-dimensional nanodots.
-irradiation and heavy-ion beam in Aoen, B.*; Sakashita, Tetsuya; Kakizaki, Takehiko; Funayama, Tomoo; Hamada, Nobuyuki*; Wada, Seiichi*; Kobayashi, Yasuhiko; Goto, Ken*
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 120, 2007/02
no abstracts in English
Aoen, B.*; Sakashita, Tetsuya; Kakizaki, Takehiko; Funayama, Tomoo; Hamada, Nobuyuki*; Wada, Seiichi*; Kobayashi, Yasuhiko; Goto, Ken*
no journal, ,
no abstracts in English
ZAoen, B.*; Sakashita, Tetsuya; Kakizaki, Takehiko; Funayama, Tomoo; Hamada, Nobuyuki*; Wada, Seiichi*; Kobayashi, Yasuhiko; Goto, Ken*
no journal, ,
no abstracts in English
2 surfaceYamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Hasegawa, Satoshi*; Goto, Seiichi*; Nakano, Takuya*; Suemitsu, Maki*; Narita, Yuzuru*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
We have investigated the initial oxidation process on an Si(110)-162 surface by real time synchrotron radiation photoemission spectroscopy (SR-XPS). As a result, a rapid initial oxidation regime was found to exist on this surface, which is not present on other crystal orientations. Analyses of the O1s spectra suggest insertion of oxygen atoms at the Si-Si bonds as the predominant process during initial oxidation. The rapid initial oxidation is accompanied by decrease of the Si2p subpeak that is related to Si(110)-162 reconstruction, indicating the preferential oxidation at the pentagon pair.
2 surfaceTogashi, Hideaki*; Yamamoto, Yoshihisa*; Goto, Seiichi*; Takahashi, Yuya*; Nakano, Takuya*; Kato, Atsushi*; Hasegawa, Satoshi*; Konno, Atsushi*; Suemitsu, Maki*; Asaoka, Hidehito; et al.
no journal, ,
no abstracts in English
2Nakano, Takuya*; Hasegawa, Satoshi*; Togashi, Hideaki*; Kato, Atsushi*; Goto, Seiichi*; Teraoka, Yuden; Yoshigoe, Akitaka; Suemitsu, Maki*
no journal, ,
no abstracts in English
Asaoka, Hidehito; Yamada, Yoichi; Yamazaki, Tatsuya; Girard, A.*; Yamamoto, Hiroyuki; Shamoto, Shinichi; Arnoldo, A.*; Goto, Seiichi*; Suemitsu, Maki*
no journal, ,
We reports the recent progress about structural formation on semiconductor surface: real-time stress analysis of Ge nanodot growth on Si(111)-77 surfaces, and preparation of the single-domained Si(110)-162 surface.
2 surface and surface reconstructionTogashi, Hideaki*; Yamamoto, Yoshihisa*; Goto, Seiichi*; Takahashi, Yuya*; Nakano, Takuya*; Konno, Atsushi*; Suemitsu, Maki*; Asaoka, Hidehito; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Initial oxidaion processes at Si(110)-162 clean surface with O
mokecules have been observed by real-time SR-XPS and STM methods. SR-XPS experiments were performed at BL23SU in SPring-8 and STM experiments were performed in JAEA Tokai research center. From comparison of oxygen uptake curves of Si(110)-162 with Si(001)-21, following conclusions were obtained. Rapid initial oxidation occured at the Si(110) surface and layer-by-layer oxidation was also took place. In-situ observation with STM revealed that the rapid initial oxidation was due to oxygen adsorption at pentagon-pair Si atoms on the topmost surface, at least 4 kinds of oxygen-adsorbed states, and the DD site was a condensed oxidation state.
Asaoka, Hidehito; Yamazaki, Tatsuya; Shamoto, Shinichi; Alguno, A.*; Goto, Seiichi*; Suemitsu, Maki*
no journal, ,
no abstracts in English
2 surface observed by SR-PESYamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Hasegawa, Satoshi*; Nakano, Takuya*; Goto, Seiichi*; Teraoka, Yuden; Yoshigoe, Akitaka; Suemitsu, Maki*
no journal, ,
In this study, we have investigated adsorption of oxygen molecules on Si(110)-162 clean surface at room temperature by synchrotron radiation photoemission spectros (SR-PES). The SR-PES experiments were conducted at the surface chemistry end-station of BL23SU in the SPring-8. The photon energy was 334 eV. Samples were B-doped p-type Si(110) wafers, and were flash-annealed in an UHV ambient prior to the exposure to oxygen gas at room temperature at the gas pressure of 6.710
Pa. By observing a structural change after a mild annealing, we have confirmed presence of a metastable state of oxidation on this RT-oxidized Si(110) surface.
2 surface using SR-PES and STMYamamoto, Yoshihisa*; Togashi, Hideaki*; Goto, Seiichi*; Takahashi, Yuya*; Nakano, Takuya*; Kato, Atsushi*; Hasegawa, Satoshi*; Konno, Atsushi*; Suemitsu, Maki*; Yoshigoe, Akitaka; et al.
no journal, ,
We have investigated that initial oxidation processes of Si(110) surfaces at room temperature and thermal stability of the oxide layer via synchrotron radiation photoemission spectroscopy (SR-PES) and scanning tunneling microscopy (STM). We found in the SR-PES experiments that metastable oxygen-condensed local structures were formed in the early stage of Si(110) oxidation at room temperature. After thermal annealing of 15 min at 573 K, highly-oxidized components of Si2p spectrum, Si
and Si
, were enhanced whereas Si
was decreased. This is due to structural relaxation of the strained metastable oxidation structures on the surface and following change to stable highly-oxidized structures. Furthermore, the structural change from the metastable structure in the surface oxidized at room temperature to the stable cluster structure was directly observed via STM.
2 surface by Si 2p photoemission spectroscopyYamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Hasegawa, Satoshi*; Goto, Seiichi*; Nakano, Takuya*; Suemitsu, Maki*; Narita, Yuzuru*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Initial oxidation process of Si(110)-162 clean surface has been investigated with synchrotron radiation photoemission spectroscopy. We found that the intensity of the alpha peak, one of the surface core level shifts in the Si 2p photoemission spectra, decreased in the just early stage of oxidation. And it was possible to relate this component with the rapid initial oxidation, which was unique to Si(110) surface. According to recent studies, this component was attributed to the 1st and the 2nd Si layer. We also found that there were significant amount of Si component just after introducing the oxygen gas, which was contrast to the oxidation of Si(001) surface.
Togashi, Hideaki*; Yamamoto, Yoshihisa*; Goto, Seiichi*; Takahashi, Yuya*; Nakano, Takuya*; Konno, Atsushi*; Suemitsu, Maki*; Asaoka, Hidehito; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Oxygen-adsorbed Si(110)-162 surfaces at room temperature and their thermally-treated surfaces were analyzed by real-time photoemission spectroscopy with synchrotron radiation (SR-PES) and scanning tunneling microscopy (STM). Thermal stability of the oxygen-adsorbed Si(110) surfaces was clearified. By thermal annealing of Si(110) surface exposed to 10L oxygen gas at room temperature, photoemission peak positions of Si and Si components were shifted to higher energy side by 0.20eV and 0.12eV,respectively, and reached nearly to those of thermal oxide films. This behaviour is due to change of Si-O-Si bond angle and Si-O bond length. The STM observation for Si(110) surfaces revealed that the oxygen-adsorbed surface structure changed to the condensed oxide structure by thermal annealing. These SR-PES and STM results showed that the oxygen-adsorbed Si(110)-162 structure was metastable and changed to more stable condensed oxide structure by thermal annealing.
