The H diffusion in MmxTb1−xCo2–H (x = 0, 0.1 and 0.2) was studied in the H solid solution phase (α-phase) by measuring the time-dependence of the H pressure during H absorption (figure 1). The measurements were carried out between 500 and 700C, under pressures of 50, 70 and 90mbar. The diffusion coefficient data could be described by an Arrhenius relationship. The partial enthalpy and chemical potential of dissolved H were deduced from pressure-composition isotherms. The dependence of the diffusion coefficient, activation energy and chemical potential of dissolved H upon the alloy content of MmxTb1−xCo2–H (x = 0, 0.1 and 0.2) was examined.

Interstitial Hydrogen Diffusion in MmxTb1-xCo2–H (x = 0, 0.1 and 0.2). M.K.Kumar, S.Ramaprabhu: Journal of Alloys and Compounds, 2008, 453[1-2], 121-6