The study of atomic and magnetic order of the iron alloys by Moessbauer spectroscopy

The results of Moessbauer spectroscopy studies on iron based alloys are described. The main and important feature of the alloys are structural and magnetic orderings which are responsible for the physical properties of these materials. Ordered and disordered samples as well as those ones which exhibit large segregation of the components and also amorphous materials were investigated. It was shown, that the Moessbauer effect is a unique method for such studies, since it permits to observe the phenomena on atomic scale. Spin hamiltonian which describes hyperfine interactions was used to determine the nearest and more distant neighbourhood of the atoms and to study the microstructure. In alsifer alloys which are used for manufacturing magnetovisual heads, perfect ordering and a tendency of preferential occupation were discovered. General formulae for selective occupation sites were derived. Spinodal decomposition occuring in alnico alloys due to thermomagnetic treatment was traced. In material used for permanent magnets texture structure was observed as a results of column crystalization. Early stages of crystalization in amorphous alloys were investigated as well as their magnetic anisotropy transverse to layer plane. Moessbauer tests for materials are proposed. The results have a common physical basis: they concern ferromagnetism of alloys. It was shown that Moessbauer spectroscopy can and should play an important role in the metallurgy of magnetic alloys. (Author)