Effect of surface modifications of Pd by ion irradiation on the characteristics of hydrogen absorption

Abe, Hiroshi; Morimoto, Ryo*; Aone, Shigeo*; Uchida, Hirohisa*; Oshima, Takeshi

In previous studies, the induction of vacancy in palladium (Pd) was found to be effective for an increase in the initial hydrogen absorption rate. As well known, the initial hydrogen absorption rate depends strongly on the surface conditions of metals. Based on these results, we made surface modifications of Pd using various ions at TIARA, JAEA. In this study, we perform Cr ion irradiation into Pd, and the hydrogen absorption rate of ion irradiation Pd was evaluated. The Pd irradiated at a fluence to 110 cm exhibited the highest rate in all samples, and the hydrogen absorption rate became five times higher than that of un-irradiated Pd. Since vacancy type defects which might act as hydrogen trapping site are introduced by irradiation the enhancement of the hydrogen absorption rate obtained inthi study can be interpreted in terms of an increase of hydrogen trapping saites near the surface region due to irradiation of Cr ion into Pd.