中文摘要：

通过电弧熔炼制备了Gd2Co Si2-xAlx（x=0,0.1,0.3）系列合金。X射线粉末衍射分析表明该系列合金的主相为具有单斜Sc2Co Si2型结构、空间群为C2/m的Gd2Co Si2相;能谱分析表明在Gd2Co Si2中Al对Si的最大替代量为4 at.%。磁性测量表明：该系列合金的居里温度及最大磁熵变随着Al替代量的增加而减小,在500 Oe外磁场下居里温度分别为226 K、205 K和196 K;在0--20 k Oe磁场变化下的最大磁熵变分别为-1.36、-1.29和-1.23 J/（kg·K）。所有合金的相变类型均为二级磁相变。

英文摘要：

Gd2CoSi2-xAlx（x = 0, 0. 1,0.3） alloys were prepared by arc melting. Analysis of X-ray powder diffraction show that the Gd2 CoSizphase with the monoclinie S% CoSi2 type structure （space group C2/m） is the major phase of these alloys. The maximum amount of the substitution of A1 for Si is 4 at. %. Magnetic measurements show that the Curie temperature and the maximum magnetic en- tropy change of GdzCoSi2-xAlx（x = 0, 0. 1,0. 3） alloys decrease with the increasing A1 content. The Curie temperature under an applied magnetic field of 500 Oe are 226 K, 205 K and 196 K, respectively for Gd2CoSiz_xAlxwith x = 0, 0. 1 and 0. 3. The maximum magnetic entropy changes for a mag- netic field change of 0- 20 kOe are -1.36, -1.29 and -1.23 J/（ kg· K） , respectively. All the alloys exhibit the second-order magnetic transition.