The lattice parameters of various series of pseudo-binary rare-earth-transition metal laves phase compounds

Measurements have been made of the lattice parameters in several series of substituted rare-earth-transition metal Laves phase compounds. It has been found that a general curve may be used to represent the variation of the lattice spacing in those compounds which contain iron. Most of the specimens examined show a positive deviation from Vegard's Law for the cubic C15 structure. In addition however, the hexagonal C36 phase has been found to coexist in some compounds and the atomic volume of this phase shows a negative deviation from a linear interpolation between the terminal phases.