Magnetic phase transition, magnetocaloric and magnetotransport properties in Pr0.55Sr0.45MnO3 perovskite manganite

Abstract

Herein, we report a systematic study on magnetic phase transitions, magnetocaloric and magneto-transport properties in praseodymium strontium manganite (PSMO), Pr0.55Sr0.45MnO3 synthesized using nitrate route method. The structure and phase formation were checked by Rietveld refinement of powder X-ray diffraction (XRD) at room temperature and it was found that Pr0.55Sr0.45MnO3 crystallizes in an orthorhombic structure with Pnma space group with lattice parameters a = 5.423(6) Å, b = 7.660(7) Å & c = 5.478(7) Å with cell volume V = 227.63 Å3. By analyzing the temperature and field dependence of magnetization, we find that the sample exhibits a sharp rise in magnetization below 281 K (TC) and a dip in magnetization around 182 K (TN), suggesting paramagnetic (PM) to ferromagnetic (FM) and ferromagnetic (FM) to antiferromagnetic (AFM) transition respectively at the said temperatures. The critical exponents β = 0.449(8), γ = 1.113(9) and δ = 3.476(4) for TC = 282 ± 0.5 K estimated from magnetic isotherms using modified Arrott plot follows the scaling theory. The maximum entropy change (-ΔSmaxM) and the relative cooling (RC) near PM-FM transition are found to be respectively 2.49 Jkg−1 K−1 and 112 J/kg for magnetic field 3 T proposing as potential magnetic refrigerant. The entropy behavior also suggested typical second order transition in the sample. The temperature dependence electrical resistivity shows a metal to insulator transition around 156 K at 0 T and shifts to 188 K with the application 8 T magnetic field. At 5 K, the observed magneto-resistance (MR) is 55%, a value maximum at 8 T.