Electrical, magnetic and magnetocaloric properties of polycrystalline Pr0.63A0.07Sr0.3MnO3 (A=Pr, Sm and Bi)

•Pr0.63A0.07Sr0.3MnO3 (A= Pr, Sm and Bi) manganites exhibit important magnetic properties.•Sm and Bi based sample are characterized by phase separation phenomenon.•Huge magnetocaloric effect was recorded for the sample Pr0.7Sr0.3MnO3.

We studied the effects of the partial substitution (10%) of praseodymium by samarium and bismuth, on the structural, magnetic, magnetocaloric and electrical properties of the Pr0.63A0.07Sr0.3MnO3 (A=Pr, Sm and Bi) manganites prepared using the solid state reaction. Refinement of the X-ray diffraction patterns shows that all our samples are single phase and crystallize in the orthorhombic structure with Pnma space group. Magnetic studies indicate that all the samples exhibit a ferromagnetic–paramagnetic transition with increasing temperature. Curie temperature TC decreases by substitution. M(H) curves indicate the presence of some antiferromagnetic domains in the substituted samples testifying the phase-separated nature of these samples. The magnetic entropy curves –ΔS(T) show a maximum in vicinity of TC. Important values of maximum of −ΔS are recorded for our compounds. For the parent compound, we found 4.59 J/kg K for an applied magnetic field of 2 T at TC=266 K which raises the possibility of using this compound as a magnetic refrigerant. The temperature dependence of the electrical resistivity ρ(T) indicates that all compounds exhibit a metal-insulator transition with increasing temperature. Electrical study suggests the presence of a correlation between electrical and magnetic properties.