CaCu5-type, whereas the HoNi2.6Ga2.4-type is observed for the A2-sample. The structural properties of GdNi3Al2 (M- and A1-samples) are more complicated; the electron diffraction patterns suggest the occurrence of a new superstructure of the hexagonal CaCu5-type. The study of the electrical and magnetic properties of these compounds shows that GdNi3Ga2 is ferromagnetic (TC=18.0(5) K), GdNi3Sn2 orders
通过熔融(M样品)并随后在1273 K(A1样品)或1073 K(A2样品)中退火获得的三元化合物GdNi 3 X 2(X = Al,Ga或Sn)的晶体结构已经确定。借助X射线粉末衍射和透射电子显微镜进行了研究。GdNi 3 Sn 2在所有温度下均以六方晶系的HoNi 2.6 Ga 2.4型结晶。GdNi 3 Ga 2有两种:高温形式(M样品)采用六角形CaCu 5型,而HoNi 2.6 Ga 2.4对于A2-样品观察到-型。GdNi 3 Al 2(M-和A1样品)的结构特性更为复杂。电子衍射图表明出现了六方CaCu 5型的新的上部结构。对这些化合物的电磁性能的研究表明,GdNi 3 Ga 2具有
铁磁性(T C = 18.0(5)K),GdNi 3 Sn 2反
铁磁性(T N = 19.5(5)K)和GdNi 3 Al 2(M-或A1样品)表现出
铁磁行为(T C= 20.0(5)K)。而且,