The diffusion of D at low temperatures was measured by using ion-implantation techniques and secondary ion mass spectroscopy. The diffusion constants were found to be equal to 10-20 and 10-18m2/s at 20 and 70C, respectively. These values were considerably smaller than those previously reported for a similar temperature range. By taking account of the compensation effect, the differences between these diffusion constants and those previously reported were analyzed by assuming the presence of 2 parallel and/or series diffusion channels. The analysis could distinguish between scatter in diffusion data, and compensation effects, and suggested that the observed diffusion constants for H were not necessarily unique for a given material, but depended upon the sample preparation method and the temperature at which the measurements were performed.

M.Sonobe, S.Tada, S.Ikeno, K.Ashida, K.Watanabe: Journal of Nuclear Materials, 1990, 175, 47-54