Magneto-structural correlations in Fe-25 at%Al influenced by substitution of Fe by Co and by thermal treatment

Abstract

The scanning electron microscopy, X-ray diffraction, positron annihilation spectroscopy, Mossbauer spectrometry, and measurements of magnetic characteristics by vibrating sample magnetometer complemented by theoretical simulations are applied in the present investigations of the Fe-Al-Co alloys with 25 at% Al and Co substituting Fe in amount of 15 at% or 25 at%. The alloys prepared by slightly different technologies resulting in different structural morphologies are subjected to thermal treatment followed by slow cooling and water cooling. It is shown that the alloy with lower Co content and the initial A2 structure is more sensitive to the thermal treatments from the viewpoints of changes in morphology, defects concentration and magnetic properties in comparison to the other one with the initial B2 structure. This is reflected almost in all experimentally obtained results.