Magnetic and magnetocaloric properties of perovskite manganite Pr0.55Sr0.45MnO3

(Ln= trivalent rare earth, A= divalent alkaline earth) should be one of the most promising materials since its Curie temperature and saturation magnetization are strongly composition dependent and the magnetic refrigeration can be realized at various temperature range [7]. Furthermore, taking into account that their higher resistivity is beneficial for reducing eddy current heating, the perovskite manganites have been suggested as a strong candidate for application in magnetic refrigeration technology. The perovskite Pri,SrxMn03 is an important member in manganite family with intermediate one electron bandwidth [8]. The Pr-based manganites show many novel properties including the charge ordering (CO) state, FM and antiferromagnetic (AFM) coexistence, and metamagnetic transition [9-11]. As x < 0.4, it possesses a strong FM-PM phase transition and a large magnetoresistance effect. As x >0.5, it shows a CO-antiferromagnetic (AF) state. In this paper, we select composition of Pro(.55)Sra45Mn03, which just lies at the boundary of FM and CO-AF phase, to investigate the MCE due to its high Curie temperature and a tunable magnetic phase boundaries which maybe possess a potential power applied in magnetic refrigeration technology. In this paper, we have studied the magnetic and magnetocaloric properties of the perovskite manganite Pr0.55Sr0.45MnO3. It shows a sharp paramagnetic-ferromagnetic phase transition at 291 K and possesses a moderate magnetic entropy change near room temperature. In addition, a large relative cooling power (143.64 J/kg) and a wide temperature range (84 K) have been found in this material. Compare with the Landau model, we find that the itinerant electrons mainly contribute the larger magnetic entropy change at paramagnetic region. (C) 2011 Elsevier B.V. All rights reserved. [GRAPHICS] .