Large Magnetic Entropy Change in Perovskite La_0.67-xGd_xCa_0.33MnO₃

Magnetic entropy change larger than that of gadolinium has been observed in perovskite manganese oxides La_0.67-xGd_xCa_0.33MnO₃ (x =0, 0.1, 0.15) with fixed carrier concentration. The large magnetic entropy change produced by the abrupt reduction of magnetization is attributed to the anomalous thermal expansion just at the Curie temperature. This phenomenon indicates potential applications for magnetic refrigerants in an extended high temperature range.