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Sato, Yusuke*; Fukaya, Yuki; Cameau, M.*; Kundu, A. K.*; Shiga, Daisuke*; Yukawa, Ryu*; Horiba, Koji*; Chen, C.-H.*; Huang, A.*; Jeng, H.-T.*; et al.
Physical Review Materials (Internet), 4(6), p.064005_1 - 064005_6, 2020/06
Times Cited Count:6 Percentile:31.09(Materials Science, Multidisciplinary)no abstracts in English
Tagawa, Masahito*; Yokota, Kumiko*; Kitamura, Akira*; Matsumoto, Koji*; Yoshigoe, Akitaka; Teraoka, Yuden; Kanda, Kazuhiro*; Niibe, Masahito*
Applied Surface Science, 256(24), p.7678 - 7683, 2010/10
Times Cited Count:13 Percentile:50.83(Chemistry, Physical)Surface structural changes of a hydrogenated diamond-like carbon (DLC) film exposed to a hyperthermal atomic oxygen beam were investigated by Rutherford backscattering spectroscopy (RBS), synchrotron radiation photoelectron spectroscopy (SR-PES), and near-edge X-ray absorption fine structure (NEXAFS). It was confirmed that the DLC surface was oxidized and etched by high-energy collisions of atomic oxygen. RBS and real-time mass-loss data showed a linear relationship between etching and atomic oxygen fluence. SR-PES data suggested that the oxide layer was restricted to the topmost surface of the DLC film. NEXAFS data were interpreted to mean that the sp structure at the DLC surface was selectively etched by collisions with hyperthermal atomic oxygen, and an sp-rich region remained at the topmost DLC surface. The formation of an sp-rich layer at the DLC surface led to surface roughening and a reduced erosion yield relative to the pristine DLC surface.
Tagawa, Masahito*; Yokota, Kumiko*; Matsumoto, Koji*; Kitamura, Akira*; Yamada, Noriko*; Kanda, Kazuhiro*; Niibe, Masahito*; Yoshigoe, Akitaka; Teraoka, Yuden; Belin, M.*; et al.
no journal, ,
We have investigated on degradation of hydrogenated diamond-like carbon (HDLC) surfaces by atomic oxygen beams for space environments under laboratory environments. HDLC was formed on silicon surfaces by a plasma CVD method. The atomic oxygen neams were generated by a laser detonation method. The HDLC surfaces modified by the atomic oxygens were analyzed by Synchrotron Radiation Photo-Emission Spectroscopy (SRPES), Ratherford Backscattering Spectroscopy (RBS), Elestic Recoil Detection Analysis (ERDA), Near-Edge X-ray Absorption Fine Structure method (NEXAFS). Chemical bonding states of oxygen atoms were almost maintained as they were. Concentrations of carbon and hydrogen, sp/sp ratio were decreased by the action of oxygen atoms. We concluded that carbon atoms in the sp state were selectively etched out.
Tagawa, Masahito*; Yokota, Kumiko*; Kitamura, Akira*; Matsumoto, Koji*; Yamada, Noriko*; Kanda, Kazuhiro*; Niibe, Masahito*; Yoshigoe, Akitaka; Teraoka, Yuden; Belin, M.*; et al.
no journal, ,
Degradation of hydrogenated diamond -like carbon surfaces in space environments by action of high speed atomic oxygen beams has been investigated in laboratory environments. The HDLC was prepared on Si substrates by a plasma CVD method. High speed oxygen atomic beams were generated by a laser detonation method. The HDLC surfaces irradiated by the oxygen atomic beams were analyzed by Synchrotron Radiation Photoemission Spectroscopy (SRPES), Ratherford Backscattering Spectroscopy (RBS), Elastic Recoil Detection Analysis (ERDA), Near-Edge X-ray Absorption Fine Structure (NEXAFS). Although chemical bonding states of oxygen atoms were maintained as they were even after the oxygen atomic beam irradiation, concentrations of carbon and hydrogen were decreased. The sp/sp ratio was also decreased. Consequently, carbon atoms in the sp state were selectively etched out with hydrogen atoms by chemical reactions with oxygen atomic beams.
Tagawa, Masahito*; Yokota, Kumiko*; Kitamura, Akira*; Matsumoto, Koji*; Yoshigoe, Akitaka; Teraoka, Yuden; Kanda, Kazuhiro*; Niibe, Masahito*
no journal, ,
In this study, the change of sp/sp ratio in a hydrogenated diamond-like carbon irradiated by hyperthermal atomic oxygen beams has been investigated by a near edge X-ray absorption fine structure method. The near edge X-ray absorption fine structure measurements, Rutherford back scattering measurements, and photoemission spectroscopic measurements were performed at the BL9 of NewSUBARU synchrotron facility, Kobe University, and BL23SU of SPring-8 facilities, respectively. It was found that the sp component, which was characteristic to a grafite structure, was selectively etched off by hyperthermal atomic oxygen beams with 2 eV. This result is consistent with previously obtained information of a larger erosion rate of grafite in the space environment than diamond.
Hasegawa, Takayuki*; Uemura, Masaharu*; Takueuchi, Kazuki*; Kodaka, Takuya*; Fukada, Noboru*; Umesaki, Norimasa*; Fukushima, Sei*; Teraoka, Yuden; Haruyama, Yuichi*; Niibe, Masahito*; et al.
no journal, ,
no abstracts in English