Photoemission study of the oxidation process via hyperthermal O adsorption at Cu and CuAu

Cu及びCuAu表面での超熱エネルギー酸素の吸着による酸化過程の光電子放出研究

岡田 美智雄*; 盛谷 浩右*; 寺岡 有殿; 吉越 章隆 ; 笠井 俊夫*

Okada, Michio*; Moritani, Kosuke*; Teraoka, Yuden; Yoshigoe, Akitaka; Kasai, Toshio*

超音速酸素分子線を用いてCu表面の酸化過程を放射光光電子分光によって研究してきた。これまでCu(001), Cu(110), Cu(111), Cu(410)の酸化過程について研究した結果、以下の結論を得た。並進運動エネルギーの効果で室温でもCuOを形成する。CuOの形成は衝突誘起酸素吸収機構による。また、CuAuの酸化では第一層が銅の酸化層になり第二層目のAuが酸化を抑制することも明らかになった。

Oxidation processes at Cu surfaces induced by supersonic oxygen molecular beams has been studied by photoemission spectroscopy with synchrotron radiation. Oxidation processes of Cu(001), Cu(110), Cu(111), and Cu(410) has been investigated by now. Following conclusions were obtained. CuO structures were formed even at room temperature by an action of translational kinetic energy of oxygen molecules. The formation of CuO structure is due to adsorbed-oxygen absorption mechanisms induced by succesive molecular collisions. Furthermore, Cu oxide layer is formed as the first layer and an Au underlayer as the second layer protects further oxidation.