Reversal Magnetocaloric Effect in the Antiferromagnetic TbFe2Al10 Compound

Magnetocaloric effect (MCE) technology is considered as one of the most important fundamental thermodynamic effects, and plays an important role in the refrigeration area for its high energy-efficiency and eco-friendly characteristics. Rear earth based low temperature magnetic refrigerant shows broad application prospect in the future. Low cost and high processability are so important to the application in the refrigeration machine. In this paper, pure phase TbFe2Al10 was prepared by arc melting and long-time annealing process. The magnetic properties and magnetocaloric effect (MCE) of the TbFe2Al10 compound were intensively studied. It was determined to be antiferromagnetic with the Neel temperature TN =18 K. Two metamagnetic transitions from antiferromagnetic (AFM) to ferrimagnetic (FIM) and ferrimagnetic to ferromagnetic (FM) state occurred at 5 K under a crucial applied magnetic field of 0.95 T and 1.89 T, respectively. Field variation generated a large MCE and no magnetic hysteresis loss was observed. The maximum values of magnetic entropy change (ΔS) were found to be -4.5 J/kg K and –6.7 J/kg K for the field changes of 0-5 T and 0-7 T, respectively. The large ΔS with no hysteresis loss as well as low proportion of rare earth (Tb) in crude materials make TbFe2Al10 a competitive candidate as low temperature magnetic refrigerant.