Comparison of surface modification and deuterium retention in W and W-Cr alloy film under high energy deuterium ion implantation

摘要

Pure W film and W-Cr alloy film prepared by magnetron sputtering were exposed to high-energy (30 keV) deuterium ions at room temperature with flux of about 1.76 x 10(17) D/m(2)s to the fluence of 0.89 x 10(22) D/m(2). Surface morphologies before and after irradiation are observed by SEM. The non-hollow lid blisters are appeared on the surface after deuterium ion implantation, which are considered to be produced by diffusion and agglomeration of deuterium atoms. The cracks of deuterium-implanted W below the surface indicate that the deuterium trapped in the material is supersaturated due to the deuterium concentration exceeding the solubility of the material. In addition, deuterium retention properties after irradiation are examined by TDS. The total amount of released deuterium in pure W film is slightly higher than that in W-Cr alloy film, implying that the refined grain size of W-Cr alloy film would suppress the blister behavior and deuterium retention.