Metamagnetic transition and extremely large low field magnetocaloric effect in La0.7Ca0.3MnO3 manganite

Abstract
Metamagnetictransition was observed in low magnetic field for La 0.7 Ca 0.3 Mn O 3 − δ lanthanum manganite prepared by solid-state technology. Magnetization shape causes giant low field magnetocaloric effect at Curie temperature T C = 242 K . Magnetic entropy changes Δ S m , deduced with isothermal magnetization curves, are equal to 7.0 and 8.0 J ∕ kg K in the field change from 0 to 1.0 and 2.0 T , respectively. The obtained Δ S m are essentially higher than that reported before for lanthanum manganites with similar T C . The observation shows the way for the construction the magnetic refrigerants, working in the field of permanent magnets, which is beneficial for household and automotive applications.