样品La_(0.71)Ca_(0.2)Sr_(0.06)MnO_3的磁制冷性能

Magnetic Refrigeration Properties of Sample La_(0. 71)Ca_(0. 2)Sr_(0. 06)MnO_3

采用溶胶-凝胶法,将存在La空位的La0.77Ca0.2MnO3母体材料进行Sr掺杂,制备了钙钛矿样品La0.71Ca0.2Sr0.06MnO3,从相结构,磁化曲线等方面分析研究其具有大磁熵变的原因。在外加磁场1 T时,该样品磁熵变Δ|SM|达到2.32 J·kg-1·K-1,居里温度TC为270.6 K。该样品低磁场下在室温附近有较强的制冷力,可作为良好的室温磁制冷材料。

Using the vacancy-La La0.77 Ca0.2 MnO3 as matrix materials, Polycrystalline perovskites La0.71 Ca0.2 Sr0.06 MnO3 have been prepared by the sol-gel method. The reason of large magnetic entropy change was analyzed by phase structures and magneti- zation curves. The maximum magnetic entropy change of 2. 32 J . kg-1 . K-1 is obtained near its Curie temperature （270. 6 K） under the field of I T for La0. 71 Ca0. 2 Sr0. 06 MnO3 sample. The Sample possess stronger cooling ability near room temperature under low magnetic field, and can be used as a good room temperature magnetic refrigeration materials.