The generation of lattice defects, and their effects upon H absorption, was investigated. Although the desorption pressure did not depend significantly upon the number of cycles, the absorption pressure decreased markedly between the first and second cycles. Numerous edge dislocations, with Burgers vectors of 1/3<1¯2•0>-type (as well as numerous cracks), were introduced during the first absorption cycle. The introduction of numerous lattice defects (such as a-type edge dislocations), and the formation of severe cracks, appeared to have be completed during the first cycle; thus resulting in reproducible pressure-composition characteristics during subsequent cycles. The response to hydrogenation seemed to be closely related to the ductility.

Lattice Defects Introduced during Hydrogen Absorption-Desorption Cycles and their Effects on P-C Characteristics in Some Intermetallic Compounds. H.Inui, T.Yamamoto, M.Hirota, M.Yamaguchi: Journal of Alloys and Compounds, 2002, 330-332, 117-24