Correlation between magnetocaloric and electrical properties based on phenomenological models in La _0.47 Pr _0.2 Pb _0.33 MnO ₃ perovskite

We have investigated the correlation between magnetocaloric and electrical properties of La _0.47 Pr _0.2 Pb _0.33 MnO ₃ perovskite prepared using the sol–gel method. Rietveld analysis of X-ray diffraction (XRD) pattern shows pure crystalline phase with rhombohedral R3c structure. Magnetic entropy change, relative cooling power (RCP) and specific heat were predicted from M(T, μ ₀ H) data at different magnetic fields with the help of the phenomenological model. The magnetic entropy change reaches a maximum value |ΔS ^max _m of about 3.96 J kg ⁻¹ K ⁻¹ for μ ₀ H = 5 T corresponding to RCP of 183 J kg ⁻¹ . These values are relatively higher, making our sample a promising candidate for the magnetic refrigeration. Electrical-resistivity measurements were well fitted with the phenomenological percolation model, which is based on the phase segregation of ferromagnetic-metallic clusters and paramagnetic-semiconductor regions. The temperature and magnetic field dependences of resistivity data, ρ(T, μ ₀ H), allowed us to determine the magnetic entropy change (ΔS _M ). Results show that the as-obtained magnetic entropy change values are similar to those determined from the phenomenological model.