Due to the potential applications in next-generation micro/nano electronic devices and functional materials, magnetic germanium (Ge)-based clusters are receiving increasing attention. In this work, we reported the structures, electronic and magnetic properties of CrMnGe_n with sizes n = 3–20. Transition metals (TMs) of Cr and Mn tend to stay together and be surrounded by Ge atoms. Small sized clusters with n ≤ 8 prefer to adopt bipyramid-based structures as the motifs with the excess Ge atoms absorbed on the surface. Starting from n = 9, the structure with one TM atom interior appears and persists until n = 16, and for larger sizes n = 17–20, the two TM atoms are full-encapsulated by Ge atoms to form endohedral structures. The Hirshfeld population analyses show that Cr atom always acts as the electron donor, while Mn atom is always the acceptor except for sizes 3 and 6. The average binding energies of these clusters increase with cluster size n, sharing a very similar trend as that of CrMnSi_n (n = 4–20) clusters, which indicates that it is favorable to form large-sized clusters. CrMnGe_n (n = 6, 13, 16, 19, and 20) clusters prefer to exhibit ferromagnetic Cr–Mn coupling, while the remaining clusters are ferrimagnetic.

中文翻译：

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CrMnGen (n = 3–20)团簇的磁性


由于在下一代微纳电子器件和功能材料中的潜在应用，磁性锗（Ge）基团簇正受到越来越多的关注。在这项工作中，我们报道了尺寸 n = 3–20 的 CrMnGe _n 的结构、电子和磁性。 Cr 和 Mn 的过渡金属 (TM) 倾向于呆在一起并被 Ge 原子包围。 n ≤ 8 的小尺寸团簇更喜欢采用双锥体结构作为基序，多余的 Ge 原子吸附在表面。从n = 9开始，内部有一个TM原子的结构出现并持续到n = 16，对于更大的尺寸n = 17-20，两个TM原子被Ge原子完全封装，形成内嵌结构。赫什菲尔德布居分析表明，除了尺寸为 3 和 6 之外，Cr 原子始终充当电子供体，而 Mn 原子始终充当受体。这些团簇的平均结合能随着团簇尺寸 n 的增加而增加，与团簇尺寸 n 的趋势​​非常相似CrMnSi _n (n = 4–20) 团簇，这表明有利于形成大尺寸团簇。 CrMnGe _n （n = 6、13、16、19 和 20）团簇更倾向于表现出铁磁 Cr-Mn 耦合，而其余团簇则为亚铁磁。