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Ogawa, Shuichi*; Takakuwa, Yuji*; Ishizuka, Shinji*; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*; Teraoka, Yuden; Yoshigoe, Akitaka; Moritani, Kosuke; Hachiue, Shunsuke
JAERI-Tech 2004-046, 25 Pages, 2004/06
We investigated the correlation between initial sticking coefficient and O transitional kinetic energy to understand O adsorption processes on the Ti(0001) surface via photoemission spectroscopy for O-1s and Ti-2p core levels using the surface reaction analysis apparatus, installed at the JAERI soft X-ray beamline BL23SU in the SPring-8. We observed the decrease of initial sticking coefficient of O molecules on the Ti(0001) surface with increasing O transitional kinetic energy. We concluded that the O adsorption on the Ti(0001) surface proceeded by a trapping-mediated dissociative adsorption mechanism. The constant dependence of the initial sticking coefficient on incident angle of O beams also suggested the propriety of the trapping-mediated surface reaction mechanism.
Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Moritani, Kosuke; Ogawa, Shuichi*; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*
Shinku, 47(6), p.457 - 461, 2004/06
The oxidation reaction of Ti(0001) surface by oxygen molecules was observed by real-time in-situ photoemission spectroscopy using synchrotron radiation in the conditions of 400C and 3.710 Pa. The uptake curve of oxygen showed a plateau at the dose of 45-85 L and then increased again. This re-growth of oxide film was attributed to the drastic change of Ti oxidation state from TiO to TiO. Consequently, the characteristic change of the uptake curve was caused by the oxidation state change of Ti atoms.
Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*
Hyomen Kagaku, 24(8), p.500 - 508, 2003/08
Temperature dependence of the initial oxidation kinetics of Ti(0001) surface was investigated by low energy electron diffraction (LEED) and real-time photoelectron spectroscopy. The LEED observation revealed that the oxide layers grew epitaxially. From the oxygen uptake curve, it was clarified that oxigen diffusion was significantly enhanced by surface temperature and the oxide layers thickness reached to 7 nm at 400C. From Ti-2p photoelectron spectroscopy, TiO was predominant at the subsurface while TiO and TiO components were also observed at the interface.
Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Yamauchi, Yasuhiro*; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*
Applied Surface Science, 216(1-4), p.395 - 401, 2003/06
Times Cited Count:18 Percentile:64.24(Chemistry, Physical)Real-time in-situ observation using photoelectron spectroscopy for elementary processes of Ti(0001) oxidation by O molecules has been performed at the surface reaction analysis apparatus installed at the BL23SU in the SPring-8. And the real-time observation has been also performed by RHEED-AES methods at Tohoku University. The partial pressure region of oxygen was from 2x10 Torr to 8x10 Torr. The surface temperature was 473 K and 673 K. The variation from clean Ti surface toward TiO was comfirmed by observation of Ti-2p and O-1s photoelectron spectra. Reflected electron intensity and O-KLL Auger electron intensity oscillated in the RHEED-AES measurements. These facts revealed that the surface morphological change of the oxidized Ti(0001) surface was associated not only with a disappearance of the surface metallic layer but also with a change of the oxidation state.
Takakuwa, Yuji*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Teraoka, Yuden; Mizuno, Yoshiyuki*; Tonda, Hideki*; Homma, Teiichi*
Nuclear Instruments and Methods in Physics Research B, 200, p.376 - 381, 2003/01
Times Cited Count:10 Percentile:56.54(Instruments & Instrumentation)no abstracts in English