Mössbauer study of a novel series of ternary rare-earth iron-rich intermetallics: ND(Fe1-xTi x )6+y(x ∼ 0.1 and 0≤y≤5)

A study of the Nd-Fe-Ti phases at the Fe-rich end of the phase diagram has been carried out using⁵⁷Fe Mössbauer spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). In particular,⁵⁷Fe Mössbauer spectroscopy has been used to characterize the phases present in these samples. In addition to the two well-known 217 and 112 phases, twonovel phases have been identified, with compositions denoted by3–29 and9–94, which are closely linked to the orthorhombic ScFe₆Ga₆-type and the hexagonal TbCu₇-type structures, respectively. The possible crystal structures of these new phases will be discussed in terms of the dumbbell substitution sequence in the CaCu₅ structure.