Structural, magnetic, and magnetocaloric properties of (1 − x )La 0.7 Ca 0.3 MnO 3 /( x )La 0.7 Ag 0.3 MnO 3 composites

In this study, structural, magnetic, and magnetocaloric properties of (1 − x )La 0.7 Ca 0.3 MnO 3 /( x )La 0.7 Ag 0.3 MnO 3 ( x = 0, 0.25, 0.50, 0.75, and 1) composites were investigated in detail. The X-ray diffraction has indicated that the samples have a single phase without any detectable impurity. SEM analysis revealed that samples consist of irregularly shaped and strongly connected particles and grain boundaries become unclear with increasing x . The magnetic measurements revealed that the parent compounds exhibit a ferromagnetic to paramagnetic phase transition. The magnetization curves for composite samples exhibited two magnetic phase transitions nearly same temperature that of the parent compounds. The maximum value of magnetic entropy change (|∆ S m |) decreased from 8.02 for x = 0 to 4.1 J/kg K for x = 0.75 at 5 T magnetic field change. Overlapping entropy peaks becomes almost flat over a wide temperature range for composite samples inducing an enhancement of the RCP (= 273.96 J/kg for x = 0.75 at 5 T magnetic field change). Arrott plots showed a second-order magnetic phase transition for composite samples and also confirmed in terms of Landau theory.