LAUSR

This work is devoted to investigating the magnetic and magnetocaloric properties of La 0.45 Nd 0.25 Sr 0.3 MnO 3 -CuO composite prepared by the solid-state reaction with various concentration of CuO (2 wt.%, 5 wt.%, and 10 wt.%). The X-ray diffraction (XRD) and the scanning electron microscopy (SEM) techniques were used to identify the obtained structural phases and microstructural morphologies in the prepared pellets. A second-order transition was observed with critical a temperature around 294 K for 2 wt.% and 10 wt.% and 321 K for 5 wt.% of the CuO phase in the composite. Magnetic entropy changes in La 0.45 Nd 0.25 Sr 0.3 MnO 3 -CuO composites were calculated using the Maxwell approximation around the magnetic transition. The highest values of magnetic entropy change were found for 5 wt.% of CuO in La 0.45 Nd 0.25 Sr 0.3 MnO 3 -CuO pellet composites which is attributed to the localization of the copper oxide in the grains boundaries of La 0.45 Nd 0.25 Sr 0.3 MnO 3 perovskite.