Structural Analysis and Theoretical Investigations of the Magnetocaloric Effect for La0.7Ba0.15Ag0.15MnO3 Manganite Prepared Using Sol-Gel Route

Abstract

Structural analysis, magnetocaloric properties, and theoretical investigations of the magnetocaloric effect were carried out in the crystalline La0.7Ba0.15Ag0.15MnO3 manganite prepared using sol-gel route. The phase purity and structure of this sample were checked by X-ray diffraction technique and Rietveld analysis. From magnetic measurements, the ferromagnetic to paramagnetic (FM-PM) phase transition was observed around TC= 255 K.The maximum change in magnetic entropy (∆𝑆 𝑀 𝑚𝑎𝑥 ) and relative cooling power (RCP)extracted from magnetic measurements were 3.48 J×kg-1×K -1 and 225 J×kg -1 at an applied magnetic field of 5 T. These magnetocaloric parameters offer to the sample the possible use in the magnetic refrigeration technology. The magnetic-entropy simulation by using different theories such as the Weiss molecular mean-field theory and the Landau theory shows good correlation between the theoretical values of -∆SM(T) and the experimental ones estimated from Maxwell relation.