The diffusion of H in this cubic (C15-type) Laves phase Ho1-xMmxCo2 alloys (x = 0, 0.2 and 0.4, Mm = mischmetal) was measured in the α-phase (solid solution) region of 500 to 800C by using a Sieverts-type apparatus. The alloys and its hydrides were characterized by using the powder X-ray diffraction Rietveld method. The diffusion constants were deduced from the gas–solid reaction, where the gas-pressure dependence upon time was measured at a fixed temperature. The results were explained on the basis of Fick’s law of diffusion. The dependence of diffusion constant upon alloy composition and initial pressure was evaluated.

Diffusion of Hydrogen in Cubic Laves Phase Ho1-XMmxCo2 (X = 0, 0.2 and 0.4) Alloys. G.Srinivas, V.Sankaranarayanan, S.Ramaprabhu: International Journal of Hydrogen Energy, 2007, 32[14], 2965-70