Theoretical investigation of the magnetocaloric effect of La0.7(Ba, sr)0.3MnO3 compound at room temperature with a second-order magnetic phase transition

Abstract

In this paper, the prediction of magnetic and magnetocaloric properties of La0.7(Sr,Ba)0.3MnO3 (LSBMO) compound have been conducted using a phenomenological model. Indeed, the investigation of magnetic properties has revealed that the sample exhibits a paramagnetic to ferromagnetic phase transition. Interestingly, the Curie temperature (TC) was found to decrease from 322 to 300K with the decrease of magnetic fields. Moreover, the magnetocaloric data displays a large value of the magnetic entropy change, 1.5Jkg−1K−1 under an applied magnetic field change of 20kOe, which increases with the increase of the applied magnetic field, making it a promising compound for ecologically-friendly magnetic refrigeration at room temperature. Finally, the construction of the universal curve of the magnetic entropy change proves that the studied manganite undergoes a second order magnetic phase transition.