The mechanism of hydrogen-induced amorphization in intermetallic compounds

In this article, the amorphization mechanisms of intermetallic compounds by hydrogen absorption are discussed on the basis of reported experimental results. It is found that there are two different modes for amorphization. One is a gradual and thermally activated process, while the other is a strain-induced reaction during hydrogen absorption. As factors affecting the amorphization modes, the hydrogen concentration and the elastic property of the compound are discussed. Of these two factors the elastic property of the compound plays a key role on the amorphization. When an elastic strain exceeding the elastic limit was imposed on the compound, the crystal lattice was not deformed plastically but collapsed into the amorphous state because the brittleness of the compound did not permit plastic deformation.