A comparison of magnetocaloric effect in ( and Sr; and 0.04)

In this work, we compare and contrast electrical, magnetic and magnetocaloric properties of undoped ( x = 0 ) and 4% Cr-doped Pr0.6A0.4Mn1−xCrxO3 (A=Ca and Sr). It is shown that while Cr-doping in A=Ca transforms the charge ordered antiferromagnetic insulator into a ferromagnetic metal, it decreases the ferromagnetic transition temperature ( T C )  and magnetic moment for A=Sr. The change in magnetic entropy, Δ S m = − 5.99 J/kg K for Δ H = 5 T around T C = 155 K of x = 0.04 and A=Ca is superior to that of x = 0.04 and A=Sr ( Δ S m = − 2.08 J/kg K at T C = 290 K ). The large magnetic entropy in Pr0.6Ca0.4Mn0.96Cr0.04O3 is attributed to the field-induced suppression of short-range charge-orbital ordering and antiferromagnetic fluctuations present above T C . Our results indicate that Cr substitution in charge ordered manganites is one of the possible ways to enhance magnetocaloric effect in these complex oxides.