Structure stability maps for intermetallic AB5 compounds

The structural stability of AB, compounds (A=lanthanide, alkaline earth, transition element; B=d- and/or p-block element) has been modelled in terms of atomic properties and represented in the form of structure stability maps. The results on some 520 known binary and ternary known representatives show that the various structure types form rather well-defined stability domains in three-dimensional space spanned by valence electron concentration, VEC, electronegativity difference, Deltachi, and radius ratio, R-A/R-B. Emphasis is placed on hexagonal CaCu5 type compounds that occur within the intervals 5.5<VEC<9.5, -0.3<Deltachi<0.1 and 1.3<R-A/R-B<1.5. The maps are of interest for the search of new hydrogen storage materials, in particular those containing light and inexpensive 3d transition metals (Fe, Mn, etc.). (C) 2003 Elsevier B.V. All rights reserved.