Polycrystalline Al_7+xFe₂₃Ge_14−x-type orthorhombic Al_8.5−xFe₂₃Ge_12.5+x (0 ≤ x≤3) compounds were studied by X-ray diffraction measurement, metallographic examination, and magnetization and electrical resistivity measurements. The lattice parameters show anisotropic x dependences, reflecting a lower symmetry of rather complex crystal structure. In the x = 0 sample, a ferromagnetic (FM) transition occurs at the Curie temperature $T_{\text{C}}$ of 255 K, which is systematically reduced with increasing x and disappears at x = 2.5 where an antiferromagnetic (AFM) ground state is realized. The Néel temperature $T_{\text{N}}$ seems to appear at x$\ge$1, and grows to 143 K at x = 3 with the increment of x. In the intermediate range of x (1$\le$x$\le$2), a FM to AFM phase transition occurs below $T_{\text{C}}$. In the AFM phase, the electrical resistivity ρ shows a Fermi surface instability characterized by the upturn of ρ below approximately $T_{\text{N}}$. The competition between the FM and AFM states would be ascribed to the anisotropic x dependences of Fe–Fe bond lengths.

多晶的Al _{7+ X}的Fe ₂₃戈_{14- X}型的斜方晶的Al _{8.5- X}的Fe ₂₃戈_{12.5+ X}（0≤  X通过X射线衍射测定，金相检验，和磁化强度和电阻率测量研究≤3）化合物。晶格参数显示出x各向异性，反映出相当复杂的晶体结构的对称性较低。在x  = 0的样本中，居里温度发生铁磁（FM）跃迁${Ť}_{\text{C}}$255 K时，它随着x的增加而系统地减小，并在x  = 2.5时消失，从而实现了反铁磁（AFM）基态。内尔温度${Ť}_{\text{ñ}}$似乎出现在x$\ge$1，并且生长到在143ķ X  = 3的增量X。在x（1$\le$X$\le$2），从FM到AFM的相变发生在下面 ${Ť}_{\text{C}}$。在AFM阶段，电阻率ρ显示出费米表面不稳定性，其特征是ρ的上升趋势低于大约${Ť}_{\text{ñ}}$。FM和AFM状态之间的竞争将归因于Fe-Fe键长的各向异性x依赖性。