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

摘要

We have investigated effect of Sm ion substitution on structural, magnetic and magnetocaloric properties of solgel synthesized (La(1-x)Smx)(0.85)K0.15MnO3 (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 R3c 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 (T-c) 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 (-Delta S-M(max)) 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.