Tunable magnetocaloric effect in Sr1 − x Ca x Mn0.5Ti0.5O3 perovskites

Sr1 − x Ca x Mn0.5Ti0.5O3 (x = 0.25, 0.5 and 0.75) polycrystalline samples were synthesized by conventional solid-state reaction. Magnetic characterizations of Sr1 − x Ca x Mn0.5Ti0.5O3 revealed signature of antiferromagnetic ordering at temperatures (T N) ~19, 25 and 29.5 K for x = 0.25, x = 0.5 and for x = 0.75, respectively. Sr1 − x Ca x Mn0.5Ti0.5O3 (x = 0.75) exhibits field-induced antiferromagnetic to ferromagnetic transition at ~30 K with applied magnetic field of 4 and 5 T. Magnetocaloric change (ΔS M) increases from 3.5 to 19 J/kg K by increasing calcium concentration in the A-site. Those ΔS M values are relatively very high in these classes of antiferromagnetic perovskite systems and equal to the magnetisation values of the ferromagnetic perovskite manganites. This is the first report for the Sr1 − x Ca x Mn0.5Ti0.5O3 (x = 0.75) having large magnetic entropy changes induced by the low magnetic field.