Diffusion of hydrogen in cubic Laves phase Ho(1-x)Mm(x)CO(2) (x=0, 0.2 and 0.4) alloys

作者：Srinivas G; Sankaranarayanan V; Ramaprabhu S^*

来源：International Journal of Hydrogen Energy, 2007, 32(14): 2965-2970.

DOI：10.1016/j.ijhydene.2007.01.003

• cubic Laves phase AB(2) type
• rare earth and mischmetal
• kinetics of hydrogen absorption
• diffusion constant
• activation energy

The diffusion of hydrogen in cubic (C15-type) Laves phase Ho(1-x)Mm(x)Co(2) (x=0, 0.2 and 0.4, Mm=mischmetal) alloys was measured in the alpha-phase (solid solution) region over the temperature range of 500-800 degrees C using Sieverts-type apparatus. The alloys and its hydrides have been characterized by powder X-ray diffraction (XRD) Rietveld method. The diffusion constants have been determined from the gas-solid reaction, where the gas pressure dependence on time has been measured at fixed temperature. The results have been discussed on the basis of Fick's law of diffusion. The dependence of diffusion constant on alloy composition and initial pressure has been evaluated. Activation energy is obtained from the temperature dependence of diffusion using Arrhenius relation.

• 出版日期2007-9