Magnetic and magnetocaloric properties of perovskite La0.7Sr0.3Mn1-xCoxO3

In this paper, the magnetic properties and magnetocaloric effect in La0.7Sr0.3Mn1-xCoxO3 prepared by conventional solid state reaction have been studied. The samples have rhombohedra crystal structure as was determined by room temperature X-ray diffraction. From the measurements, it was found that the Curie temperature (T-c) and magnetic entropy change (Delta S-M) are strongly dependent on the Co content. The Curie temperature was found to be 338, 300 and 260 K for x=0, 0.05 and 0.1, respectively. Although the variation of maximum entropy change shows a similar tendency with T-c the phase transition temperatures were widened and the vertical bar Delta S-M vertical bar(max) values, under a change of the magnetic field of 15 kOe, amount to -1.36, -1.17 and -0.92 J/kg K for x=0, 0.05 and 0.1, respectively. The results suggest that Mn-site substitution should be used to tailor Curie temperature and achieve large relative cooling power (RCP). (C) 2012 Elsevier B.V. All rights reserved.