It was noted that the migration energies of H atoms in rare-earth metals, which were obtained by using the H disorder-order transition, could be divided into 2 groups: high values and low values. The high values were approximately twice the low values. The cause of this discrepancy was explained in terms of an incorrect estimation of the order of the reaction in the rate equation for the low-value group. The high and low values of the migration energy agreed well with each other upon using the correct order for the reaction.

Migration of Hydrogen in Rare-Earth Metals at the Disorder-Order Transition. K.Yamakawa: Journal of Physics - Condensed Matter, 1999, 11[25], L261-5