Abstract
This study investigates the magnetocaloric properties of Sm2Mn2O5 (SMO), synthesized via the solid-state
method. SMO crystallizes in the orthorhombic Pbam space group, with Mn3+ and Mn4+ occupying square pyramidal
and octahedral sites. Structural analysis reveals Jahn-Teller-driven distortions influencing magnetic
exchange, resulting in a stable and reversible magnetocaloric effect (MCE). Magnetic and thermodynamic
measurements show a ferromagnetic (FM) transition (TC ≈ 53.1 K) within a Griffiths phase (51.8–96.6 K) and a
field-independent antiferromagnetic (AFM) transition (TN ≈ 14.4 K). The maximum magnetic entropy change
(-ΔSm) is 8.6 J/kg⋅K with a refrigerant capacity (RC) of 76.5 J/kg under a 5T field. These results underline SMO’s
stability and efficiency as a magnetocaloric material. Structural distortions and ligand field effects are key to
enhancing its performance. SMO emerges as a promising candidate for low-temperature magnetic refrigeration,
with potential for optimization through doping.