Magnetocaloric Effect in Perovskite Manganite La0.65Nd0.05Ba0.3MnO3 with Double Metal-Insulator Peaks

With Nd3+ ionic doping, series of perovskite manganites La0.7-x Nd (x) Ba0.3MnO3 (x=0, 0.05, 0.1) were prepared by the sol-gel technique. The magnetocaloric correlative measurement of La0.65Nd0.05Ba0.3MnO3 was representatively carried out. Double metal-insulator peaks being found on the resistivity-temperature curves of samples, the maximum of magnetic entropy change was found to be Delta S (H)=-1.3 J/kg K and its refrigerant capacity 52 J/kg, obtained in the vicinity of room temperature under the variation of 1 T magnetic field. The comparative faint Nd3+ magnetic inhomogeneity submerged in the double-exchange strong magnetic signal along with the differential coefficient of the magnetic moment with temperature, in the physical definition of the magnetic entropy change, resulting in a single peak on the magnetic entropy change curve.