The present study demonstrates the magnetocaloric and magnetoresistive behaviors of La0.67Sr0.3□0.03MnO3 manganite synthesized via the solid-state method. The X-ray diffraction pattern shows that the material exists in a single phase with rhombohedral structure (R \(\overline{3 }\) c). The Transmission Electron Microscopy (TEM) observation implies that the material has a homogeneous microstructure with well-crystallized grains. Magnetization measurements reveal a ferromagnetic–paramagnetic phase transition at Curie temperature of 360 K. Under an external magnetic field of 5 T, the magnetocaloric effect displays a maximum magnetic entropy change (ΔSmax = 4.58 J.kg⁻1.K⁻1) and a relative cooling power (RCP = 268.34 J kg⁻1), thus highlighting the material's effectiveness for magnetic cooling. Using the modified Arrott plot and the Kouvel-Fisher method the critical exponents β, γ, and δ near Tc are determined which are found similar to those of the 3D-Ising model. The magnetoresistance properties indicate a strong dependence of resistivity on the applied magnetic field denoting its usefulness for spintronics and magnetic field detection with high sensitivity. These results prove that La0.67Sr0.3□0.03MnO3 is a versatile material with technological potential recommended for magnetic cooling systems as well as next generation electronic and magnetic devices.
