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研究了LaGd_(0.1)Fe_(11.4-x)Co_xSi_(1.6)(x=0.1,0.3,0.5,0.7,0.9)系列合金的结构以及磁热效应.室温XRD分析表明该系列合金除微量的α-Fe相外,均具有立方NaZn_(13)型立方单相晶体结构,空间群为Fm-3c.晶格常数没有明显变化,分别为1.1458,1.1454,1.1458,1.1459,1.469 nm.磁性测量表明该系列合金的T_c随着Co含量的增加而增加,分别为212,231,253,281,302 K.在外磁场变化AB=1.5 T时,最大的磁熵变随着Co含量的增加而减少,由x=0.1的13.8 J降为x=0.9 J·kg~(-1)·K~(-1)的1.5 J·kg~(-1).K~(-1).并且随着Co含量的增加存在由一级相变转为二级相变的趋势.“,”The effect of substitution of Co for Fe on the structure,magnetic properties and magnetic entropy changes in LaGd_(0.1)Fe_(11.4-x)Co_xSi_(1.6)(x=0.1,0.3,0.5,0.7,0.9)was investigated.The X-ray diffraction showed that LaGd_(0.1) Fe_(11.4-x)Co_x Si_(1.6)(x=0.1,0.3,0.5,0.7,0.9)alloys consisted of the NaZn_(13)-type phase(Fm-3c)and minor amount of α-Fe phase.There were no obvious changes of cell constants,1.1458,1.14549,1.1458,1.1459,1.469 nm for x=0.1,0.3,0.5,0.7 and 0.9,respectively.Magnetic measurements showed that the Curie temperature of the alloys increased from 212 K to 302 K by changing the Co content from 0.1 to 0.9.the giant magnetic entropy change decreased from (13.8J·Kg_(-1)·K_(-1))to (1.5J·Kg_(-1)·K_(-1)) for x=0.1 and x=0.9under a magnetic field varying from 0 to 1.5 T.Additionally,there was a trend from first-order phase transition to second-order phase transition with increasing Co concentration.