中文摘要：

利用固态反应法制备了Mn3Sn1-xCoxC1.1（x =0.05,0.1,0.2）系列化合物,研究了Co掺杂对其磁性质、相变、熵变的影响.随着Co掺杂量的增加,样品的居里温度由283 K先降到212 K （Mn3Sn0.9Co0.1C1.1）后又升到332 K （Mn3Sn0.2Co0.8C1.1）,相变类型由一级相变逐渐转变为二级相变.增大Co的掺杂量, Mn3Sn1-xCoxC1.1化合物的熵变峰值逐渐减小,磁熵变温区由9 K展宽到300 K.当Co掺杂量为0.2时,相对制冷量达到最高,为103 J/kg （磁场强度为1.6 MA/m）.由于室温附近良好的磁致冷效应,该类材料在磁制冷领域可能具有重要的应用前景.

英文摘要：

The Mn3Sn1-xCoxC1.1 compounds are synthesized by a solid-state reaction method. The effects of Co doping on the magnetic properties, phase transition and entropy change are investigated in Mn3Sn1-xCoxC1.1 compounds. The Curie temperature first decreases from 283 K to 212 K （Mn3Sn0.9Co0.1C1.1） with increasing the Co concentration, and then increases to 332 K （Mn3Sn0.2Co0.8C1.1） with further increasing the Co concentration in Mn3Sn1-xCoxC1.1. The first-order transition of Mn3Sn1-xCoxC1.1 gradually changes into the second-order transition, in the mean time, the entropy change decreases and the phase transition region broadens from 9 K to 300 K with increasing the Co content. Both the magnetic entropy change and broadening the transition temperature span can influence the relative cooling power R. Finally we obtain the large R=103 J/kg （H =1.6 MA/m） in Mn3Sn0.8Co0.2C1.1, which could be used as the room-temperature magnetic refrigerant materials.