Effect of Fe substitution on charge order state and magnetocaloric effect in Pr0.5Sr0.5Mn1−xFexO3 (0.00 ≤ x ≤ 0.08) manganites

The charge order state and magnetocaloric effect have been studied in Pr0.5Sr0.5Mn1−xFexO3 (0.00 ≤ x ≤ 0.08) prepared by conventional solid-state reaction. Charge order state is weak in parent Pr0.5Sr0.5MnO3 and absent with increasing doping level. The long range charge order antiferromagnetic state (CO/AFM) reemerges for x = 0.06 and subsequently weak accompanied with rapid collapse in double exchange ferromagnetic order for x = 0.08. Magnetic measurements indicate that Fe does not participate in the double exchange interaction, the Curie temperature (TC) is systematically depressed with increasing Fe content from 265 K (x = 0.00) down to 185 K (x = 0.06). Negative magnetic entropy change (ΔSMmax) of −0.96 J/kg K and large positive value of 2.57 J/kg K in Pr0.5Sr0.5Mn0.94Fe0.06O3 are achieved when it undergoes paramagnetic to ferromagnetic (PM-FM) and ferromagnetic to antiferromagnetic (FM-AFM) magnetic phase transition in a magnetic change of 15.0 kOe. Though the materials with considerable magnetic hysteresis in FM-CO/AFM because of first order magnetic phase transition, it gives a strategy to obtain change order state in manganites.