中文摘要：

采用X射线衍射和磁性测量等方法,研究LaFe11.6-xCoxSi1.4（x=0.1,0.2,0.3）系列化合物的结构和磁性.结果表明：LaFe11.6-xCoxSi1.4（x=0.1,0.2,0.3）的主相为NaZn13型立方结构,空间群为Fm-3c;随着Co含量的增加,该系列化合物的居里温度TC升高,x=0.1时TC约为202.2 K,并且具有大的磁熵变;外加磁场为1.5 T时,磁熵变-ΔSm=16.1 J/（kg.K）.大的磁熵变来源于TC处磁化强度的陡峭变化和TC以上磁场诱发的变磁转变.

英文摘要：

The structural and magnetic properties of LaFe11.6-xCoxSi1.4（x=0.1,0.2,0.3） compounds have been investigated by means of X-ray diffraction and magnetic measurements.The XRD results show that all the compounds crystallize in the NaZn13-type structure（space group Fm-3c）.The Curie temperature increases with increasing Co content.The Curie temperature is about 202.2K and the maximum value of the magnetic entropy change is found to be 16.1J/（kg·K） for LaFe11.5Co0.1Si1.4 compound for a field change from 0 to 1.5T.The large magnetic entropy change is attributed to the sharp change of the magnetization in the vicinity of Curie temperature and the field-induced transition.