Kinetic isotope effects in hydrogen absorption by α-zirconium

• Published in: The Journal of chemical physics 1984-01, Vol.81 (8), p.3489-3494
• Main Authors: NAITO, S, HASHINO, T, KAWAI, T
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Materials science; Metals, semimetals and alloys; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Solubility, segregation, and mixing; phase separation; Specific materials
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.448075

The absorption rates for gaseous hydrogen and deuterium and their solubility in polycrystalline α-zirconium metals have been investigated over the temperature range of 773–1073 K. A model is considered in which the absorption process is composed of three successive steps: the dissociative adsorption, the jump of the adsorbed atom into the interstitial site, and its diffusion into the metal bulk. The expressions for the isotope effects corresponding to these steps and to the solubility are formulated in terms of the absolute rate theory. The expressions show a dependence of the isotope effects on each other. The experimental results are adequately described by the expressions if the quantum corrections for the vibrations of hydrogen and deuterium in the gas phase, in the metal bulk, and on the metal surface are taken into account. The adsorption, as well as the diffusion, is slower and the solubility is smaller for deuterium than for hydrogen under the imposed experimental conditions in this investigation.