Study on the influence of magnetic phase transitions on the magnetocaloric effect in Sm0.7Sr0.3Mn0.95Fe0.05O3 manganite

• The nanosize Sm0.7Sr0.3Mn0.95Fe0.05O3 manganite was synthesized.
• The sample exhibits both normal and inverse magnetocaloric effects (MCE).
• The influence of first and second order magnetic phase transitions on the MCE and refrigerant capacity (RC) are reported.

In this work, the structural, magnetic, magnetocaloric effect (MCE) and refrigerant capacity (RC) properties of nanosize Sm0.7Sr0.3Mn0.95Fe0.05O3 manganite have been investigated. Structural characterization shows that this sample has orthorhombic (Pbnm) phase with the small impurities (Mn3O4). The sample undergoes second order paramagnetic to ferromagnetic transition at TC = 90 K followed by two types of magnetic states at T < TC, which is formed by the presence of second order charge ordered at TCO = 28 and first order antiferromagnetic clusters at TN = 18 K. The magnetic entropy change ΔSM changes from negative around TC to positive around TCO and TN indicating the presence of normal and inverse MCEs. The influence of first and second order magnetic phase transitions on the MCE and RC are reported.