A comparative analysis of magnetic properties and microstructure of high coercivity Sm(CoCuFe)₅ quasi-binary alloys in the framework of fractal geometry

Abstract

The results of the micro- and nanostructures investigation of Sm(CoCuFe)5 alloys by means of scanning electron and atomic force microscopy are presented. It was shown that sequential high- and low-temperature heat treatments lead to the formation of a homogeneous microstructure with nanoscale compositional heterogeneities. Such a structure provides a coercive filed of up to 32 kOe. The coercivity and remanent magnetization of the samples in the temperature range from 300 to 700 K linearly decrease. The predominant coercivity mechanism in these materials is pinning on nanoscale inhomogeneities with an increased copper concentration. The fractal dimension of the surface of the Sm(CoCuFe)5 alloy metallographic specimen was determined at different stages of heat treatments. The comparative analysis of magnetic properties and microstructure in the framework of fractal geometry was carried out.

Relationship between Remanence and Micromorphology of Nd-Fe-B Permanent Magnets Revealed by Fractal Theory and EBSD Data

“…We first introduced linear fractal dimension into the analysis of the fractal morphology of permanent magnet materials [20]. E. M. Semenova determined the fractal dimension of the atomic force microscopy image of Sm(CoCuFe) 5 alloy at different scales, while the average fractal dimension is practically the same [21]. A. D. Zigert established a relationship between the magnetic state (demagnetized state, partially magnetized by the external field) and the fractal dimension of the changed magnetic domain structure of ferrite garnet magnetic films [22].…”