Effect of Cr Substitution on Magnetic and Magnetocaloric Properties for La0.62Nd0.05Ba0.33MnO3

In this paper, we investigate the structural, magnetic, and magnetocaloric properties of La0.62Nd0.05Ba0.33Mn1-xCrxO3 manganites elaborated by sol gel process. X-ray diffraction analyses confirm that all elaborated samples are crystallized on the rhombohedral perovskite structure with R-3c space group. Magnetic measurements reveal the presence of a magnetic transition from paramagnetic (PM) to ferromagnetic (FM) phase in the vicinity of Curie temperature T-C. However, as Cr concentration increases, we witness a decrease in T-C from 285 K for x=0 to 250 K for x=0.20. This behavior can be explained by the double exchange interaction of Mn3+-O-M4+. The maximum entropy change (-Delta S-m(max)) at mu H-0= 5 T is found to be 2.63, 1.88, and 1.76 J.kg(-1).K-1 for x=0, 0.10, and 0.20, respectively. However, our research underlines the enhancement of relative cooling power (RCP) by Cr doping, from 310 to 340 J.kg(-1) as Cr concentration increases from x=0 to 0.20. This finding suggests the usefulness of our samples as magnetic refrigeration material around room temperature. Furthermore, the analysis of the magnetocaloric effect (MCE) using the Landau theory shows a good agreement with the experimental results with a soft difference, indicating the importance of Jahn-Teller interactions on manganites perovskite.