Giant magnetic entropy change in manganese perovskite La sub(0.67)Sr sub(0.16)Ca sub(0.17)MnO sub(3) near room temperature

• Published in: Journal of alloys and compounds 2014-12, Vol.615, p.290-297
• Main Authors: Mohamed, Za, Tka, E, Dhahri, J, Hlil, E K
• Format: Article
• Language: English
• Subjects: Entropy; Ferromagnetism; Magnetic fields; Magnetic properties; Magnetization; Magnetization curves; Perovskites; Refrigerants
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2014.06.169

Structural, magnetic and magnetocaloric properties of La sub(0.67)Sr sub(0.16)Ca sub(0.17)MnO sub(3) perovskite have been studied. A solid state reaction method was used in the preparation phase. X-ray diffraction analysis using Rietveld refinement revealed that this sample crystallizes in the distorted rhombohedral system with R3c space group. The variation of magnetization (M) vs. temperature (T), under an applied magnetic field of 0.05T, revealed a transition from a ferromagnetic (FM) to paramagnetic (PM) phase at around Curie temperature (T sub(C) = 336 K). Using Arrott plots, it was found that the transition is of a second-order. Isothermal measurements of magnetization allow us, through thermodynamic Maxwell relations, to determine the magnetic entropy change ( Delta S sub(M)). A large Delta S sub(M) deduced from isothermal magnetization curves, has been observed in our sample with a peak centered around its respective T sub(C). The maximum of the magnetic entropy change Delta S super(max) sub(M) in a magnetic field change of 5T is found to be 5.51 J kg super(-1) K super(-1) at 335 K. In addition, the compound showed a large relative cooling power (RCP) value of about 234 J/kg while the maximum refrigerant capacity of 174 J/kg was attained at the applied field of 5T. As a result, the studied sample can be considered as a potential material for magnetic refrigeration.