Magnetocaloric Properties of a Charge Ordered Pr₀.₄₈Sr₀.₅₂MnO₃ Perovskite Near First and Second Order Magnetic Transition

Polycrystalline Pr0.48Sr0.52MnO3 forms a tetragonal structure belonging to the I4/mcm space group. X-ray absorption spectroscopy revealed Mn3d level splitting with a higher density of state in
$e_{g}\downarrow $
. The temperature-dependent electrical resistivity plot indicates metal-to-insulator transition (
$T_{\mathrm {MI}}$
) at 224 K at 0 T. Additionally, at lower temperatures, a distinct thermal hysteresis during heating and cooling cycles between 0 and 2 T fields specifies a first-order (FOPT) magnetic phase transition. The temperature-dependent magnetization plot shows a second-order (SOPT) paramagnetic (PM) to ferromagnetic (FM) transition phase transition at 226 K (=
$T_{c}$
) followed by FM to antiferromagnetic (AFM) transition with distinct thermal hysteresis evidence of FOPT at 152.5 K (=
$T_{N}$
). The maximum isothermal entropy change (
$\Delta S_{M}$
) estimated using Maxwell’s model near SOPT is −3.67 J/kg K at 8 T. Moreover, near FOPT the maximum
$\Delta S_{M}$
of value +4.29 J/kg K at
$H$
= 4 T is determined, which thereafter remained constant up to 8 T magnetic field. The
$\Delta S_{M}$
value at a lower magnetic field is also computed using the phenomenological model. Landau’s theory suitably explains the magnetocaloric (MCE) of Pr0.48Sr0.52MnO3 near SOPT in agreement with the value obtained using Maxwell’s relation.