Study on retention behavior and chemical states of energetic deuterium implanted into carbon-contained boron film

Retention behavior and chemical states of energetic deuterium (D) implanted into a carbon-contained boron film were investigated by XPS and TDS. It was found from the TDS results that D desorption processes were consisted of following four stages. Two of them were the desorptions of D bound to B as forming B–D–B and B–D bonds, and the others were thought to be that bound to C with different configurations. These results were consistent with the XPS results, showing the C–B (sp2), C–B (sp3) and C–C bonds were formed in the carbon contained boron film. These desorption peaks were attributed to B–C–D and C–C–D bonds, and most of D was mainly trapped by C and desorption temperature was higher than trapped by B, indicating that the D trapped by C would be critical issue for the hydrogen isotope retention control in fusion devices. It was concluded that D trapped by C, especially as C–C–D bond, was chemically stable even though at high temperature.