Hydrogenation Properties of Zr Films Under Various Conditionsof Hydrogen Plasma

The hydrogenation properties of Zr samples with and without an Ni overlayer under various plasma conditions were investigated by means of non-Rutherford backscattering (non-RBS) and elastic recoil detection analysis. The theoretical maximum hydrogen capacity, 66.7at.%, could be achieved at a hydrogen absolute pressure of ～2 Pa and a substrate temperature of ～393 K for a plasma irradiation of only 10 min; this was significantly greater than that for gas hydrogenation under the same hydrogen pressure and substrate temperature. It was also found that the C and O contamination on the sample surface strongly influences the hydrogenation, and that the maximum equilibrium hydrogen content drops dramatically with the increasing total contamination. In addition, the influence of the Ni overlayer on the plasma hydrogenation is discussed.