Co掺杂对Mn$lt;sub$gt;3$lt;/sub$gt;Sn$lt;sub$gt;1-$lt;em$gt;x$lt;/em$gt;$lt;/sub$gt;Co$lt;sub$gt;$lt;em$gt;x$lt;/em$gt;$lt;/sub$gt;C$lt;sub$gt;1.1$lt;/sub$gt;化合物的磁性质、熵变以及磁卡效应的影响

利用固态反应法制备了Mn₃Sn_1-xCo_xC_1.1 （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 （Mn₃Sn_0.9Co_0.1C_1.1） 后又升到332 K （Mn₃Sn_0.2Co_0.8C_1.1），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，Mn₃Sn_1-xCo_xC_1.1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. 关键词： 磁性质 相变 磁卡效应 相对制冷量

Effects of Co doping on the magnetic properties,entropy change,and magnetocaloric effect in Mn3Sn1-xCoxC1.1compounds

The Mn₃Sn_1-xCo_xC_1.1 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 Mn₃Sn_1-xCo_xC_1.1 compounds. The Curie temperature first decreases from 283 K to 212 K (Mn₃Sn_0.9Co_0.1C_1.1) with increasing the Co concentration, and then increases to 332 K (Mn₃Sn_0.2Co_0.8C_1.1) with further increasing the Co concentration in Mn₃Sn_1-xCo_xC_1.1. The first-order transition of Mn₃Sn_1-xCo_xC_1.1 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 Mn₃Sn_0.8Co_0.2C_1.1, which could be used as the room-temperature magnetic refrigerant materials.
Keywords： magnetic properties phase transition magnetocaloric effect relative cooling power