Exotic quantum states arise from the interplay of various degrees of freedom such as charge, spin, orbital, and lattice. Recently, a short-ranged charge order (CO) was discovered deep inside the antiferromagnetic phase of Kagome magnet FeGe, exhibiting close relationships with magnetism. Despite extensive investigations, the CO mechanism remains controversial, mainly because the short-ranged behavior hinders precise identification of CO superstructure. Here, combining multiple experimental techniques, we report the observation of a long-ranged CO in high-quality FeGe samples, which is accompanied with a first-order structural transition. With these high-quality samples, the distorted 2 × 2 × 2 CO superstructure is characterized by a strong dimerization along the c-axis of 1/4 of Ge1-sites in Fe₃Ge layers, and in response to that, the 2 × 2 in-plane charge modulations are induced. Moreover, we show that the previously reported short-ranged CO might be related to large occupational disorders at Ge1-site, which upsets the equilibrium of the CO state and the ideal 1 × 1 × 1 structure with very close energies, inducing nanoscale coexistence of these two phases. Our study provides important clues for further understanding the CO properties in FeGe and helps to identify the CO mechanism.

奇异的量子态是由电荷、自旋、轨道和晶格等不同自由度的相互作用产生的。最近，在 Kagome 磁体 FeGe 的反铁磁相深处发现了短程电荷序（CO），它与磁性有着密切的关系。尽管进行了广泛的研究，CO 机制仍然存在争议，主要是因为短程行为阻碍了 CO 上层建筑的精确识别。在这里，结合多种实验技术，我们报告了在高质量 FeGe 样品中观察到的长程 CO，并伴随着一级结构转变。通过这些高质量的样品，扭曲的 2 × 2 × 2 CO 超结构的特征是沿 Fe ₃ Ge 层中 1/4 Ge1 位点的c轴发生强烈二聚化，并且响应于此，2 ×引起2个面内电荷调制。此外，我们表明，先前报道的短程CO可能与Ge1位点的大职业失调有关，这破坏了CO状态和能量非常接近的理想1×1×1结构的平衡，导致纳米级共存这两个阶段。我们的研究为进一步了解 FeGe 中的 CO 特性提供了重要线索，并有助于确定 CO 机制。