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

Abstract

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 (TC) and magnetic entropy change (ΔSM) are strongly dependent on the Co content. The Curie temperature was found to be 338, 300 and 260K for x=0, 0.05 and 0.1, respectively. Although the variation of maximum entropy change shows a similar tendency with TC, the phase transition temperatures were widened and the |ΔSM|max values, under a change of the magnetic field of 15kOe, amount to −1.36, −1.17 and −0.92J/kgK 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).