Magnetic properties and near-room-temperature large magnetocaloric effect in (La1-xBix)0.67Ba0.33MnO3 (x = 0 - 0.3) ceramics

The magnetic and magnetocaloric properties of (La_1-xBi_x)_0.67Ba_0.33MnO₃ (for x = 0 - 0.3) ceramics are reported. Magnetization measurements reveal the onset of a ferromagnetic ordering (T_C) in the range 336 K- 229 K which shifts towards low temperatures with increasing x. Magnetocaloric effect (MCE) measurements yield the maximum value of entropy change ${(-\Delta S}_M^{max})$ around T_C that decreases from ∼6.19 J/ Kg/K for x = 0 to ∼4.79 J/ Kg/K for x = 0.3 for a field change of 9 T. Remarkable enhancement in the relative cooling power (RCP) is observed with the value increasing from ∼400.45 J/Kg for x = 0 to ∼472.81 J/Kg for x = 0.3. The substantial increase in the magnetocaloric properties of (La_1-xBi_x)_0.67Ba_0.33MnO₃ compounds compared to other compounds reported in the literature makes them potential candidates to be used for magnetic refrigeration purposes.