Characterization and theoretical investigation of the magnetocaloric effect of La0.67Ba0.33Mn1-xSbxO3 compounds

In this study, the structural, magnetic and magnetocaloric properties of the polycrystalline La0.67Ba0.33Mn1-xSbxO3 (x=0.01, x=0.03 and x=0.07) were consistently investigated. X-ray analysis revealed that the substitution of Mn by Sb produced no considerable structural change just the diffraction peaks of rhombohedric symmetry were obtained all the samples. The variation of the magnetization M versus temperature T, under an applied magnetic field of 1.5 T, shows a ferromagnetic-paramagnetic transition. The experimental results exhibit that with the increase of Sb substitution TC decreases from 326 K to 296 K. The prediction of magnetic entropy change, relative cooling power and specific heat for magnetic field variation were predicted with the help of a phenomenological model. A large magneto-caloric effect has been observed, the maximum of magnetic entropy change, |ΔSmmax|, reaches the highest value of 2.74 J kg−1 K−1 under a magnetic field of 1.5 T with an RCP value of 132.8 J kg−1 for La0.67Ba0.33Mn1−xSbxO3 (x=0.07) composition , which will be an interesting compound for application materials working as magnetic refrigerants near room temperature.