Magnetocaloric Study of La0.45Nd0.25Sr0.3MnO₃/MO (MO = CuO, CoO, and NiO) Nanocomposites

The influence of transition metal oxide (MO) on the structural, magnetic, and magnetocaloric properties for La _0.45 Nd _0.25 Sr _0.3 MnO ₃ (LSMO)/ $x$ -wt.% MO (MO = CuO, CoO and NiO) nanocomposite samples has been investigated using X-ray powder diffraction (XRD) and magnetic measurements. Pure phase nanocomposites were prepared via the one-pot autocombustion method. The XRD patterns of the composite reveal the presence of a distinct pure phase of LSMO and MOs. Temperature-dependent field-cooled magnetization curve exhibits second-order phase transition near room temperature. The isothermal magnetic entropy change ( $\Delta S_{M}$ ) is calculated from magnetic isotherms. LSMO—2.5 wt.% CuO composite—display $\Delta S_{M}\sim -3.95$ J/kg $\cdot \text{K}$ , highest among studied composites, which is 110% higher than LSMO. While the relative cooling power (RCP) values were observed to be maximum for 5 wt.% CoO composite.