Hydrogen in lanthanum-magnesium-nickel alloys with structures of the L 22, D 2 d , and L 60 types

A statistical theory of the solubility of hydrogen in alloys with structures of the L2₂, D2 _d , and L6₀ types and in phase mixtures of these alloys is developed. The isotherms of absorption and desorption have been studied; their dependence on the activity of hydrogen and concentration of magnesium has been established. It is shown that with an increase in the magnesium concentration and a decrease in the activity of hydrogen, a plateau (a horizontal segment) appears and is lengthened in the isotherms. Hysteresis effects have been investigated with allowance for volume effects; the hysteresis coefficients have been estimated. The decrease in the hysteresis coefficient with increasing magnesium concentration is substantiated. The results of the theoretical calculations are compared with experimental data. Original Russian Text ? S.Yu. Zaginaichenko, Z.A. Matysina, D.V. Shchur, 2007, published in Fizika Metallov i Metallovedenie, 2007, Vol. 104, No. 5, pp. 453–464.