Diffusivity and solubility of hydrogen and deuterium in yttrium

The diffusivity and solubility of hydrogen and deuterium in polycrystalline α-yttrium have been measured in the temperature range 1073-1373 K. The ratios of the measured diffusion coefficient of deuterium to that of hydrogen showed the classical value 1/√/2. The activation energy of diffusion has been found to be 510 meV for both hydrogen and deuterium. The differences in the solubility and diffusivity between hydrogen and deuterium have been explained by using rate theory and assuming that hydrogen and deuterium atoms in yttrium are slightly anharmonic oscillators. (author)