Quenching effects on correlation between electrical and magnetic properties in Pr0.5Sr0.5MnO3 polycrystalline manganites

In this work, we studied the effect of quenching on the magnetocaloric effect and the correlation between electrical and magnetic properties of two samples polycrystalline manganites Pr0.5Sr0.5MnO3. Sample I (quenched in water) exhibits a negative maximum of magnetic entropy change ΔS around its Curie temperature with ΔS=−4.61 J kg−1 K−1 at a magnetic applied field of 8 T. Sample II (quenched in air) is characterized by the presence of two extrema of magnetic entropy change with a great positive value reaching 5.17 J kg−1 K−1 for only 2 T magnetic field around its Neel temperature. Resistivity and magnetization were found to be related with the different relations ρ=ρ0exp(−M/α) and ρ=ρ0exp(−M2/α) for samples I and II respectively. From these relations associated to Maxwell–Weiss relation, we found the way to evaluate ΔS from resistivity and the obtained results were discussed