Magnetic properties and cryogenic magneto-caloric effect in the antiferromagnetic REFe2Si2 (RE = Dy and Tb) compounds.

The rare-earth (RE)-based magnetic solids with large magneto-caloric effect (MCE) have been well investigated recently due to their potential applications in the field of environmentally friendly cryogenic magnetic refrigeration (MR). Herein, two polycrystalline RE-based REFe₂Si₂ (RE = Dy and Tb) intermetallic compounds have been prepared by an arc-melting way and determined with regard to the structural and magnetic phase transition (MPT) properties as well as the MCE and magneto-caloric performance. Both of the present REFe₂Si₂ compounds at room temperature are crystallized in a ThCr₂Si₂-type structure and undergo a first-ordered MPT from antiferromagnetic to paramagnetic state around the Néel temperature (T_N) of ~ 4.05 K for DyFe₂Si₂ and ~ 6.25 K for TbFe₂Si₂, respectively. Large cryogenic MC effect together with excellent MC performance have been realized in DyFe₂Si₂ compound. The MC parameters with magnetic field change at 0–5 T of the maximum magnetic entropy changes and the refrigerant capacity/relative cooling power were found to be 16.08 J/kgK and 318.5/403.3 J/kg for DyFe₂Si₂ and to be 9.88 J/kgK and 105.9/140.8 J/kg for TbFe₂Si₂, respectively. [ABSTRACT FROM AUTHOR]