Eur. Phys. J. Plus (2015) 130: 179
https://doi.org/10.1140/epjp/i2015-15179-0

Regular Article

The structural, magnetic and above room temperature magnetocaloric properties of La_0.5Sr_0.5MnO₃ compound

¹ Laboratoire de Physico-Chimie des Matériaux, Département de Physique, Faculté des Sciences de Monastir, Université de Monastir, 5019, Monastir, Tunisia
² Laboratoire des Matériaux et du Génie Physique (CNRS UMR 5628), Minatec Bâtiment INPG, parvis Louis Néel, BP 257, 38016, Grenoble Cedex 1, France

^* e-mail: nejib.ihzaz@issatgb.rnu.tn

Received: 6 February 2015
Revised: 24 June 2015
Accepted: 29 July 2015
Published online: 2 September 2015

Abstract

We have carried out the structural properties, magnetization measurements and magnetocaloric effects in La_0.5Sr_0.5MnO₃ perovskite prepared by the solid-state reaction formula. Crystallographic analysis was realized by Rietveld refinement of experimental X-ray diffraction data. Results show that this material has tetragonal crystal structure and exhibits a sharp ferromagnetic-paramagnetic (FM-PM) transition at a Curie temperature T _C (352 K). The experimental magnetic entropy change −ΔS _M and the relative cooling power (RCP) have been determined. The magnetocaloric data show a moderate low field magnetic entropy change above room temperature. In addition, the RCP values vary from 46.40 to 228.35 J kg⁻¹ upon variation of the applied magnetic field at 1 and 5 T, which is about 56% of the conventional refrigerant Gd material under 5 T. A good agreement is found between the experimental −ΔS _M and the one estimated by the Landau theory at the ferromagnetic region. However, the discrepancy at paramagnetic region was assigned to the contribution of itinerant electron to the large magnetic entropy change.