X-ray photoemission study of oxide formation on TiNi using a hyperthermal O molecular beam

Sowa, Makoto*; Okada, Michio*; Yoshigoe, Akitaka ; Teraoka, Yuden; Kasai, Toshio*

Oxidation reactions of a TiNi alloy have been studied at BL23SU of JAEA in the SPring-8 using supersonic oxygen molecular beams and photoemission spectroscopy with synchrotron radiation. A clean TiNi surface was obtained by an Ar ion sputtering method. The surface was exposed to oxygen gas to form a TiO surface with a small amount of Ti component. This fact suggests many defects are included in the oxide layer. On the other hand, a pure TiO layer was formed by using supersonic oxygen molecular beams with the kinetic energy of 2 eV. The thickness was about 2 nm. Furthermore, the molecular beam irradiation during sample heating at 673 K gave a pure TiO layer with the thickness of 80 nm.