Giant Magnetic Entropy Change in Manganese Perovskites near Room Temperature

A large magnetic entropy change about twice as high as that of pure gadolinium metal near room temperature has been discovered in manganese perovskites La_0.837Ca_0.098Na_0.038Mn_0.987O_3.00(8.3 J.kg^-1.K^-1, at 256K) and La_0.822Ca_0.096K_0.043Mn_0.974O_3.00 (6.8 J.kg^-1.K^-1, at 265 K) under a magnetic field of 1.5 T. This phenomenon indicates that manganese perovskites have potential applications for magnetic refrigerants in an extended temperature range even near room temperature.