摘要

A sample of Pr0.7Ca0.3MnO3 nanopowder was prepared by the ball milling method. The crystal structure examined by X-ray powder diffraction indicates that the sample is single phase and crystallizes in the orthorhombic perovskite system with Pnma space group at room temperature. The average crystallite size of 29 nm was obtained by X-ray diffraction. Magnetic measurements showed that the sample exhibits a ferromagnetic-to-paramagnetic transition at a Curie temperature close to 120 K. The magnetic entropy change |Delta S (M) | has been deduced by the Maxwell relation method. The maximum value of the magnetic entropy change obtained from the M(H) plot data is found to be 0.86 J/kg K for an applied magnetic field of 2 T. At this value of magnetic field the relative cooling power (RCP) is 44.05 J/kg. At low temperature, large change in magnetic entropy has been observed in the sample. Our result on magnetocaloric properties suggests that Pr0.7Ca0.3MnO3 nanopowder is attractive as a possible refrigerant for low-temperature magnetic refrigeration.

  • 出版日期2014-2

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