Effect of surface metal oxide on the desorption of hydrogenation from hydrogenated diamond-like carbon films

Tagawa, Masahito*; Yokota, Kumiko*; Furuyama, Yuichi*; Tode, Mayumi; Yoshigoe, Akitaka ; Teraoka, Yuden

In order to make clear an effect of surface oxide layers for hydrogen desorption processes of hydrogen storage materials, ultra-thin metal oxide layers were formed on diamond-like-carbon (DLC) surfaces containing hydrogen and metals by irradiation of atomic oxygen beams. The thickness of SiO layer formed by the atomic oxygen beam irradiation was estimated to be about 4.5-6.5 nm on the basis of Si/Si photoemission peak area ratio. This value is larger than the diffusion depth of oxygen atoms in an Si crystal at a room temperature. Thermal desorption gas analyses revealed that a hydrogen desorption temperature did not change by the atomic oxygen beam irradiation. However, a hydrogen desorption temperature decreased in the atomic oxygen beam irradiation to a DLC containing Ti. The variation of hydrogen desorption temperature depends on a kind of metal oxide layer.