Effect of indium substitution on structural, magnetic and magnetocaloric properties of La0.5Sm0.1Sr0.4Mn1−xInxO3 (0 ≤ x ≤ 0.1) manganites

In this work, we report on a detailed study of the effect of B-site Indium-doping on the structural, magnetic and magnetocaloric properties of La0.5Sm0.1Sr0.4Mn1−xInxO3 (0 ≤ x ≤0.1) compounds prepared by sol-gel method. The analysis of our samples by X-ray diffraction using Rietveld refinement showed that they crystallize in the rhombohedral system with R3¯c space group. Magnetization measurements versus temperature in a magnetic applied field of 0.05 T showed that In-doping leads to a paramagnetic (PM) - ferromagnetic (FM) transition with a Curie temperature TC decreasing from 310 K for x = 0.00 to 251 K for x = 0.10. The field dependence of the magnetocaloric properties of La0.5Sm0.1Sr0.4Mn1−xInxO3 compounds with a second order phase transition material was investigated. The maximum of magnetic entropy change in a magnetic field change of 5 T was found to be 5.88 J kg−1K−1 at 310 K, 4.53 J kg−1 K−1 at 294 K and 3.51 J kg−1 K−1 at 251 K for x = 0.00, 0.05 and 0.10, respectively. Under an applied magnetic field of 5 T, the relative cooling power (RCP) values were found to vary between 181.66 J kg−1 and 205.91 J kg−1. Our results are interesting and indicate that these compounds are useful for magnetic refrigeration in an extended high temperature range even at room temperature.