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Au with synchrotron radiation宗和 誠*; 山崎 大地*; 岡田 美智雄*; 吉越 章隆; 寺岡 有殿; 笠井 俊夫*
Electrical Engineering in Japan, 175(4), p.43 - 47, 2011/06
被引用回数：2 パーセンタイル：18.47(Engineering, Electrical & Electronic)We report the results of a study of the natural oxidation of CuAu(110) with high-resolution X-ray photoemission spectroscopy in conjunction with synchrotron radiation. The clean surface of CuAu(110) is terminated with 50% Au and 50% Cu atoms. After natural oxidation in the air, Cu atoms segregate on the surface and produce Cu-oxide. As a result, Au atoms move into the bulk. Au atoms below the oxide reduce the diffusion of O atoms farther into bulk and limit the oxide thickness. The face dependence of natural oxidation indicates that the diffusion of Cu atoms also contributes to oxide formation.
山崎 大地*; 宗和 誠*; 岡田 美智雄*; 寺岡 有殿; 笠井 俊夫*
Journal of the Vacuum Society of Japan, 54(5), p.307 - 312, 2011/05
Dtailed studies on the initial oxidation process of NiTi with a 2 eV hyperthermal oxygen molecular beam (HOMB) and thermal O
in the backfilling have been conducted. The oxidation processes are monitored by X-ray photoemission spectroscopic measurements in conjunction with synchrotron radiation. In the oxide formation process at higher oxygen coverage, HOMB has the advantage in the dissociation process of O molecule and can grow TiO layers with the underlying TiO
-rich and/or Ni-rich layers even at room temperature. Surface annealing enhances the diffusion atoms and as a result, the efficiency of Ti oxide formation. We succeeded in fabricating thick Ni-free TiO layer, possibly blue colored rutile TiO, combining HOMB and surface annealing.
岡田 美智雄*; 宗和 誠*; 笠井 俊夫*; 寺岡 有殿
Applied Surface Science, 257(9), p.4257 - 4263, 2011/02
被引用回数：11 パーセンタイル：44.51(Chemistry, Physical)We report results of our detailed studies on the initial oxidation process of TiNi with a 2 eV hyperthermal oxygen molecular beam (HOMB) and thermal O in the backfilling. The oxidation processes are monitored by X-ray photoemission spectroscopy (XPS) measurements in conjunction with synchrotron radiation (SR). In the early stages of oxidation, the precursor mediated dissociative adsorption is the dominant reaction mechanism. In the oxide formation process at higher O coverage, HOMB has the advantage in the dissociation process of O molecules and can make growth of TiO layers with the underlying TiO-rich and/or Ni-rich layers. We succeeded in fabricating a thick Ni-free TiO layer, possibly blue colored rutile TiO, combining HOMB and surface annealing.
Au表面自然酸化のシンクロトロン放射光を用いた光電子分光研究宗和 誠*; 山崎 大地*; 岡田 美智雄*; 吉越 章隆; 寺岡 有殿; 笠井 俊夫*
電気学会論文誌,C, 129(2), p.229 - 232, 2009/02
シンクロトロン放射光を用いた高分解能X線光電子分光法でCuAu(110)表面の自然酸化膜を研究した。清浄なCuAu(110)表面は等量の金と銅原子で終端されている。それを大気に曝した後では、銅原子が表面に析出して銅酸化物ができる。逆に言うと金原子がバルク中に移動する。酸化膜下の金原子は酸素原子がバルクに拡散するのを妨げる。表面の面指数を変えたどの酸化実験でも銅の拡散が酸化に寄与することがわかった。
宗和 誠*; 岡田 美智雄*; 吉越 章隆; 寺岡 有殿; 笠井 俊夫*
no journal, ,
TiNi合金の酸化反応を放射光光電子分光と超音速酸素分子線を用いて大型放射光施設SPring-8の原子力機構専用ビームラインBL23SUで行った。Arイオンスパッタリングで表面を清浄化したTiNiを酸素ガスに曝すとおもにTiOが生成する。他にTi
も生成することがわかった。これは酸化膜中に欠陥が多いことを示唆している。一方、2eVの並進運動エネルギーを持つ超音速酸素分子線を照射した場合は、TiOのみが生成することを見いだした。膜厚は2nm程度であった。さらに、基板を673Kに加熱しながら2eVの酸素分子線を照射すると80nm程度のTiO膜を形成させることができた。
山崎 大地*; 笠井 俊夫*; 宗和 誠*; 岡田 美智雄*; 吉越 章隆; 寺岡 有殿
no journal, ,
Ti-Ni alloy is one of the shape-memory materials that exhibit good resistance to corrosion. In medical field, some of implants consist of Ti-Ni alloy. However the release of nickel ion limits its application, because a trace amount of nickel ion could cause allergy. We will discuss, the effect of temperature on the formation of thin TiO layer on TiNi. The oxidation process of TiNi was investigated with synchrotron radiation X-ray photoelectron spectroscopy at BL23SU in SPring-8. The O1s XPS peak area of the oxide layer formed at 673 K approximately twice as large as that at 300 K. And the intensity of Ni2p XPS peak decreased with increasing O dose for both surface temperatures. The oxide layer obtained at 300 K contains Ni and Ti2p clearly show the absence of these species in the oxide layer formed at 673 K.
