Structural, magnetic and magnetocaloric properties of La0.8Ba0.2Mn1-xFexO3 compounds with 0 ≤ x ≤ 0.1

The present study reports the effect of Fe doping on the structural, magnetic and magnetocaloric proprieties in the La0.8Ba0.2Mn1-xFexO3 (0 <= x <= 0.1) perovskites. The studied samples were synthesized as powder samples by solid state reaction at high temperature. Their analysis by powder X-ray diffraction using Rietveld refinement showed that they crystallize in the rhombohedral system with the R (3) over barC space group. They display a paramagnetic (PM)-ferromagnetic (FM) phase transition with decreasing temperature. All of them exhibit a maximum and large magnetocaloric effect near the Curie temperature (T-C). The magnitude of the isothermal magnetic entropy vertical bar Delta S-M(max)vertical bar at the FM Curie temperature decreases from 4.15 J kg(-1) K-1 for the x = 0 composition to 2.62 J kg(-1) K-1 for x = 0.1, for a magnetic field change of 5T. For an applied magnetic field of 5T, the relative cooling power (RCP) values are found to vary between 211 and 238 J kg(-1). The phenomenon of large entropy change and the convenient adjustment of the Curie temperature make these peroskite-type manganese oxides useful for magnetic refrigeration in an extended high temperature range even at room temperature. (C) 2012 Elsevier B.V. All rights reserved.