Abstract
In this study, the magneto-caloric and magneto-transport properties of the perovskites manganites composites (x = 0.00, 0.07, and 0.18) synthesized by the solid-state reaction method are reported. X-ray diffraction (XRD) study to confirm the formation of two phases in composites. The Arrott plot analysis and master curve behavior reveal a second-order magnetic phase transition in the composite samples. Indeed, the value of the magnetic entropy (delta S-M) correlates with that predicted by Landau and Hamad models. On the other hand, the resistivity of the composite samples was measured at the applied magnetic fields of 0 T, 2 T, and 5 T. All the specimens undergo a metallic-semiconductor transition at the temperature T rho. The temperature dependence of resistivity shows that the transport behavior is governed by the grain boundaries. It is suggested that the CuO addition acts as a separation layer between grains. Therefore, around room temperature, the magnetoresistance (MR) enhancement of the composite is caused by the magnetic disorder. The enhanced MR and increment delta S-M of these composites make them attractive for potential applications.