Large magnetocaloric effect in manganese perovskite La0.67−xBixBa0.33MnO3 near room temperature
E. Dhahri,E. K. Hlil
RSC Advances Pub Date : 02/13/2019 00:00:00 , DOI:10.1039/C8RA09802F
Abstract

La0.67−xBixBa0.33MnO3 (x = 0 and 0.05) ceramics were prepared via the sol–gel method. Structural, magnetic and magnetocaloric effects have been systematically studied. X-ray diffraction shows that all the compounds crystallize in the rhombohedral structure with the R[3 with combining macron]c space group. By analyzing the field and temperature dependence of magnetization, it is observed that both samples undergo a second order magnetic phase transition near TC. The value of TC decreases from 340 K to 306 K when increasing x from 0.00 to 0.05, respectively. The reported magnetic entropy change for both samples was considerably remarkable and equal to 5.8 J kg−1 K−1 for x = 0.00 and 7.3 J kg−1 K−1 for x = 0.05, respectively, for μ0H = 5 T, confirming that these materials are promising candidates for magnetic refrigeration applications. The mean-field theory was used to study the magnetocaloric effect within the thermodynamics of the model. Satisfactory agreement between experimental data and the mean-field theory has been found.

Graphical abstract: Large magnetocaloric effect in manganese perovskite La0.67−xBixBa0.33MnO3 near room temperature