Magnetocaloric effect in high Gd content Gd-Fe-Al based amorphous/nanocrystalline systems with enhanced Curie temperature and refrigeration capacity

The Gd-Fe-Al amorphous/nanocrystalline composites were successfully designed and obtained with both high Curie temperature (T-c) and large magnetic entropy change (Delta S-M). The Tc can be tuned from 172 to 280 K and refrigeration capacity (RC) has a value between 690 and 867 J/kg under a field change of 0-5 T by changing the Gd contents and the formation of Gd nanocrystallites. And, Delta S-M in Gd-Fe-Al amorphous/nanocrystalline composites reached a value of 7.2 J kg(-1) K-1 under a field change of 0-5 T. The high RC in Gd-Fe-Al system were ascribed to the widening full width at half maximum (delta(FWHM)) up to 240 K of the magnetic entropy change (Delta S-M(max)) peak because of the combination contribution of amorphous matrix and the precipitated Gd-riched nanocrystalline. Our research would shed light on how to design attractive candidates for magnetic refrigeration materials with high performance at near room temperature. (c) 2016 Author(s).