MICROMORPHOLOGY OF THE SURFACE OF RAPIDLY QUENCHED HEUSLER-ALLOYS

The paper describes the results of the scanning electronic and atomic force microscopy research of the surface structure of the Ni57Mn21Al22, Ni57Mn21Al19Si3, Ni40Co10Mn34Al16 rapidly quenched ribbons. The influence of the chemical composition on the size, boundary geometry and structure of the grains is considered. It is shown that all the test samples have a nano-sized martensitic relief, and its parameters are determined. It has been established that the cross section of the ribbon is represented by crystalline grains of different shapes which are due to differences in the cooling rates along the edges and in the center of the samples. Elemental mapping of the cross-sectional surface of the ribbons was carried out using an X-ray energy dispersive spectrometer, and a uniform distribution of chemical elements in the samples was established. It is shown that the cobalt doping of Ni57Mn21Al22 ribbon causes changes in the micromorphology of the surface and has a significant effect on the magnetic properties of rapidly quenched ribbons: field dependences of themagnetization and domain structure.