Effect of praseodymium doping on the structural, magnetic and magnetocaloric properties of Sm0.55-xPrxSr0.45MnO3 (0.1 ≤ x ≤ 0.4) manganites

The effect of praseodymium doping on the microstructure, magnetic and magnetocaloric effects in Sm0.55-xPrxSr0.45MnO3 (0.1 <= x <= 0.4) manganite compounds has been investigated. All the samples have been elaborated using the conventional solid-state reaction at high temperature. X-ray diffraction study reveals that all the samples crystallize in the distorted orthorhombic system with Pbnm space group. The lattice parameters and unit cell volume increase gradually with increasing Pr amount. The Curie temperature Tc increases with praseodymium content from 132 K for x = 0.1 to 261 K for x = 0.4. The maximum magnetic entropy change (-Delta S-M(max)) was calculated from isothermal magnetization curves under magnetic field change of 5 T and is found to be 7.14; 5.23; 4.92 and 3.98 J/kg K for x = 0.1; 0.2; 0.3 and 0.4, respectively. The relative cooling power (RCP) reaches 240 J/kg for x = 0.4 with negligible hysteretic losses. This suggests that our compounds may be suitable for applications in magnetic refrigeration. (C) 2015 Elsevier B.V. All rights reserved.