Structural, Morphological, and Magnetocaloric Properties of Nanocrystalline Pr_0.7La_0.3MnO₃

Abstract

The structural, morphological, magnetic, and magnetocaloric properties of nanocrystalline Pr0.7La0.3MnO3 (PLMO), synthesized by using a wet chemical Sol-gel method, have been investigated. The single-phase nature of nanocrystalline PLMO with orthorhombic crystal structure along with the Pbnm space group was confirmed by Rietveld analysis of the X-ray diffraction pattern. The average crystallite size and lattice microstrain were determined using the Williamson-Hall technique, and they were found to be ~ 28 nm and ~ 0.00137, respectively. Transmission electron microscopy shows the particle size and structural characteristics of the sample. Temperature-dependent magnetization data show paramagnetic to ferromagnetic transition. According to Banerjee criterion, the positive slope of Arrott's plot for nanocrystalline PLMO indicates the second-order magnetic phase transition. In a 5 T external magnetic field, the maximum magnetic entropy change (∆SM) was found to be 2.47 J/kg K. The refrigerant capacity and relative cooling power were calculated and the values are 193.3 and 277.57 J/kg, respectively, under a 5 T applied external magnetic field.