Structural, magnetic and magnetocaloric properties of La0.7−xEuxBa0.3MnO3 perovskites

Polycrystalline perovskite manganites La0.7−xEuxBa0.3MnO3(x=0.05, 0.1 and 0.15) were prepared by sol-gel method. The prepared samples remain single phase with a perovskite structure, revealed by X-ray diffraction. The structure refinement of La0.7−xEuxBa0.3MnO3(x=0.05, 0.1 and 0.15) samples was performed in the hexagonal setting of the R3¯c space group. The dependence of magnetization M on applied magnetic field H and temperature T was measured carefully near the Curie temperature TC for all the samples. With the increasing Eu content, both the unit cell volume and Curie temperature TC of 298 K has been detected with a maximum of magnetic entropy |ΔSMmax| for the La0.7−xEuxBa0.3MnO3 with x=0.15, reaching a value of 2.3 J/kg K when a magnetic field of 10 kOe was applied and the relative cooling power (RCP) is 46 J/kg. These results suggest that the material may be a suitable candidate as working substance in magnetic refrigeration near room temperature.