Effect of Thermal Treatments Below Devitrification Temperature on the Magnetic and Magnetocaloric Properties in Mechanically Alloyed Fe70Zr30 Powders

Abstract

In this work, the relaxation of the amorphous structure of mechanically alloyed Fe70Zr30 powders has been analyzed through interrupted heating ramps below the devitrification temperature. As a result of such thermal treatment, Curie temperature and temperature at maximum magnetic entropy change curves shift to higher temperatures as the temperature of heating treatment increases. This effect can be attributed to both the release of the stress accumulated in the amorphous powder during the milling process and to the initiation of nucleation of α-Fe crystallites, as it has been shown by Mössbauer spectroscopy.