The magnetic, structural properties and magnetocaloric effects of Fe-Mn-Al alloys

Abstract The Fe15−xMn40Al45+x (x = 0, 1, 2 and 3) and Fe15Mn40−yAl45+y (y = 1, 2 and 3) alloys were prepared by arc melting and annealed at 1000 °C for 7 days. The microstructure and magnetic properties are characterized by XRD and VSM. Corresponding corrosion potential and hardness are measured by electrochemical workstation and Vickers hardness tester. All samples have CsCl type Cubic structure. And for Fe15Mn40−yAl45+y alloys, with increasing Mn content, the lattice parameters increase from 2.9613 A to 2.9678 A, while the curie temperatures can be tuned from 288 K to 330 K. As for Fe15−xMn40Al45+x alloys, the curie temperatures rise from 315 K to 340 K with lattice parameters increasing from 2.9658 A to 2.9689 A. The peak values of magnetic entropy change under 5 T are −2.4 and −3.1 J·kg−1K−1 for Fe15Mn40Al45 and Fe14Mn40Al44 respectively. The values of refrigerant capacity power are 223.4 and 232.5 J·kg−1 under 5 T. The Arrott plots are also employed to investigate the magnetic phase transition, showing all samples undergo second order ferro-paramagnetic phase transition. Furthermore, these alloys have good hardness and corrosion resistance properties. The potential applications of these alloys as magnetic refrigerant will be also discussed in this paper.