ELASTIC AND MAGNETOELASTIC EFFECTS IN INVAR-ALLOYS

A review of the elastic behaviour of Invar alloys is given. This includes (a) ferromagnetic alloys (Fe-Ni, Fe-Pt, stainless Invar); (b) antiferromagnetic alloys (Fe-Mn, Mn- and Cr-based alloys); (c) very weak ferromagnets (ZrZn2, Ni3Al, Ni-Pt); (d) amorphous alloys (Fe-B). It is shown that elastic anomalies (ΔE effects) can but need not occur simultaneously with a large thermal expansion anomaly. Various magnetoelastic contributions exist (ΔEλ, ΔEω, ΔEm) which are discussed in terms of existing theoretical models. The effect associated with a volume distortion, i.e. the bulk modulus anomaly, is shown to fit into the framework of the itinerant electron model. © 1979.