Structural, magnetic and magnetocaloric properties of (La1−xSmx)0.85K0.15MnO3 (x = 0.0, 0.1, 0.2 and 0.3) perovskite manganites

Abstract

We have investigated effect of Sm ion substitution on structural, magnetic and magnetocaloric properties of sol-gel synthesized (La1−xSmx)0.85K0.15MnO3 (x = 0.0, 0.1, 0.2 and 0.3) perovskite manganites. X-ray diffraction analyses confirm that samples crystallize with rhombohedral symmetry in the R3̅c space group. The temperature dependence of magnetization measurements shows a clear ferromagnetic (FM)-paramagnetic (PM) phase transition with increasing temperature, and magnetic phase transition temperature (TC) decreases with increasing Sm concentration. For Sm concentrations (x = 0.0, 0.1, 0.2 and 0.3), magnetic field dependence of the maximum magnetic entropy change (−∆SMmax) are determined up to 5 T to be 7.32, 3.37, 3.28 and 2.70 J kg−1 K−1, respectively. These experimental values are also in good agreement with the calculation of the magnetic entropy change using Landau theory.