The magnesium-rich intermetallic compounds Gd5Cu5Mg13 and Tb5Cu5Mg13 were obtained from direct reactions of the elements (induction melting) in sealed tantalum ampoules. Both compounds crystallize with the orthorhombic Y5Cu5Mg13 type structure, space group Cmcm and Z = 4. The polycrystalline samples were characterized by powder X-ray diffraction. The structure of the gadolinium compound was refined from single crystal X-ray diffraction data: a = 414.78(2), b = 1921.87(12), c = 2573.89(16) pm, wR2 = 0.0492, 1611 F 2 values and 77 variables. Refinement of the occupancy parameters revealed a small degree of Gd/Mg mixing for the Gd3 site, leading to the composition Gd4.93(1)Cu5Mg13.07(1) for the studied crystal. The Gd5Cu5Mg13 structure contains slabs of equiatomic GdCuMg, which are embedded in a magnesium matrix. From a geometrical point of view, one can describe the Gd5Cu5Mg13 and Tb5Cu5Mg13 structures as intergrowth variants of distorted W/CsCl and AlB2 related slabs. The most remarkable crystal chemical feature concerns the bcc like magnesium slabs with short Mg–Mg distances ranging from 300 to 342 pm. Temperature dependent magnetic susceptibility measurements show Curie-Weiss paramagnetism for Tb5Cu5Mg13 (10.5(1) μ B Tb atom−1 and Θ P = −11.6(1) K). Antiferromagnetic ordering was detected below the Néel temperatures of T N = 30.5(3) K.

中文翻译：

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富镁金属间化合物 Gd5Cu5Mg13 和 Tb5Cu5Mg13 – 与 CsCl 和 AlB2 相关板坯的共生变体

富镁金属间化合物Gd5个铜5个镁13和结核病5个铜5个镁13是通过元素在密封的钽安瓿中的直接反应（感应熔化）获得的。两种化合物均以正交晶系 Y 结晶5个铜5个镁13类型结构，空间群厘米厘米和Z= 4. 多晶样品通过粉末 X 射线衍射进行表征。由单晶 X 射线衍射数据细化了钆化合物的结构：一种= 414.78(2),b= 1921.87(12),C= 2573.89(16) 下午，wR2 = 0.0492, 1611F 2个值和 77 个变量。占据参数的细化揭示了 Gd3 位点的少量 Gd/Mg 混合，导致组成 Gd4.93(1)铜5个镁13.07(1)对于所研究的晶体。Gd5个铜5个镁13结构包含嵌入镁基质中的等原子 GdCuMg 板。从几何角度，可以描述 Gd5个铜5个镁13和结核病5个铜5个镁13结构作为扭曲的 W/CsCl 和 AlB 的共生变体2个相关的平板。最显着的晶体化学特征涉及密件抄送像具有短 Mg-Mg 距离的镁板，范围从 300 到 342 pm。温度相关的磁化率测量显示 Tb 的居里-魏斯顺磁性5个铜5个镁13(10.5(1)μ 乙 铽原子−1和 Θ P = −11.6(1) K)。在 Néel 温度以下检测到反铁磁有序吨 否 = 30.5(3) K。