Structural, magnetic and magnetocaloric properties of sol–gel prepared, nanocrystalline oxides Pr1−xAxMn1−yCoyO3 (A = Ca, Sr) (x = 0.3; y = 0.5) (cubic, space group Fm3m) have been studied. From the X-ray data, the crystallite size of Pr0.7Ca0.3Mn0.5Co0.5O3 and Pr0.7Sr0.3Mn0.5Co0.5O3 samples is found to be ∼24 nm and ∼15 nm respectively. High resolution transmission electron microscopy image shows average particle size of ∼34 nm and ∼20 nm. Magnetization measurements indicate a Curie temperature of ∼153 K and ∼172 K in applied magnetic field of 100 Oe for Pr0.7Ca0.3Mn0.5Co0.5O3 and Pr0.7Sr0.3Mn0.5Co0.5O3 compounds. The magnetization versus applied magnetic field curves obtained at temperatures below 150 K show significant hysteresis and magnetization is not saturated even in a field of 7 T. The magnetocaloric effect is calculated from M versus H data obtained at various temperatures. Magnetic entropy change shows a maximum near TC for both the samples and is of the order ∼2.5 J/kg/K.
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