Magnetocaloric study of monovalent-doped manganites Pr0.6Sr0.4-x Na x MnO3 (x=0-0.2)

A systematic investigation of structural, magnetic, and magnetocaloric properties is reported for a series of monovalent sodium-doped manganites Pr0.6Sr0.4-x Na (x) MnO3 (x = 0, 0.05, 0.1, 0.15, and 0.2). Rietveld refinements of the X-ray diffraction patterns show that all powder samples are single-phased and crystallized in the orthorhombic structure with Pnma space group. Magnetic characterization and Arrott plot confirm the second-order phase transition at Curie temperature T (C) decreasing from 310 K for x = 0 down to 272 K for x = 0.2. Magnetic entropy change is largest for x = 0 reaching 1.95 J kg(-1) K-1 at 2 T field. This corresponds to a large relative cooling power of 102 J kg(-1) . Magnetic field sensitivity of magnetic entropy change and relative cooling power are analyzed and discussed.