【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。更多还原

【Abstract】 Gd2Co Si2-xAlx( x = 0,0. 1,0. 3) alloys were prepared by arc melting. Analysis of X-ray powder diffraction show that the Gd2 Co Si2phase with the monoclinic Sc2 Co Si2type structure( space group C2 / m) is the major phase of these alloys. The maximum amount of the substitution of Al for Si is 4 at. %. Magnetic measurements show that the Curie temperature and the maximum magnetic entropy change of Gd2 Co Si2-xAlx( x = 0,0. 1,0. 3) alloys decrease with the increasing Al content. The Curie temperature under an applied magnetic field of 500 Oe are 226 K,205 K and 196 K,respectively for Gd2 Co Si2-xAlxwith x = 0,0. 1and 0. 3. The maximum magnetic entropy changes for a magnetic field change of 0 ~ 20 k Oe are-1. 36,-1. 29 and-1. 23 J /( kg·K),respectively. All the alloys exhibit the second-order magnetic transition.更多还原