中文摘要：

对制备的化合物La0.8Ce0.2(Fe1-xCox)11.4Si1.6(x=0.02,0.04,0.06)的相组成、巡游电子变磁转变(IEMT)特性和磁热效应(MCE)进行了研究。粉末X射线衍射结果表明,经1373 K真空退火处理7 d后,化合物La0.8Ce0.2(Fe1-xCox)11.4Si1.6(x=0.02,0.04,0.06)均为单相立方NaZn13型晶体结构。随着Co含量由x=0.02增加到x=0.06,样品的居里温度TC由207 K上升到277 K。在0~1.5 T磁场变化下,x=0.02,0.04,0.06时样品的最大磁熵变|ΔSM(T)|分别为40.17,12.60和7.65 J.kg-1.K-1,可见该化合物有巨大的磁熵变,而且随Co含量的增加最大磁熵变迅速减小。该化合物的巨大磁熵变来源于TC处的一级相变,以及在TC以上由磁场诱导IEMT,但由于Co原子对Fe原子的替代能够抑制变磁转变的发生,因此该系化合物最大磁熵变随Co含量的增加迅速减小。

英文摘要：

The crystal structure,itinerant-electron metamagnetic transition(IEMT) and magnetocaloric effects(MCE) in the compounds La0.8Ce0.2(Fe1-xCox)11.4Si1.6(x=0.02,0.04,0.06) have been investigated.The powder X-ray diffraction revealed that the La0.8Ce0.2(Fe1-x Cox)11.4Si1.6(x=0.02,0.04,0.06) annealed at 1373 K in vacuum for only 7 d could be crystallized in the cubic NaZn-type structure.TC tunable from 207 to 277 K with Co doping from x=0.02 to 0.06.The maximum value of |ΔSM(T)| for x=0.02,0.04,0.06 are 40.17,12....