MSi₂₀H₂₀ aggregates: from simple building blocks to highly magnetic functionalized materials.
MSi₂₀H₂₀ aggregates: from simple building blocks to highly magnetic functionalized materials.
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DOI：
10.1021/nn3058888
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发表时间：
2013-01
期刊：
影响因子：
17.1
通讯作者：
D. Palagin;K. Reuter
中科院分区：
文献类型：
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作者：
D. Palagin;K. Reuter
基于密度泛函理论的全局几何优化被用来仔细检查使用内掺杂氢化Si团簇作为构建高磁性材料的构建块的可能性。与已知的笼形面共享相比，簇表现出通过双Si-Si桥键聚集的倾向。对于原型的CrSi H簇，我们表明，减少氢化程度可用于控制其他笼可以连接到的反应位点的数量，同时仍然保持结构的完整性的积木本身。这导致了具有不同数量的双“对接位点”的CrSi双氢（20-2n）单体的工具箱，其允许构建任何形态的网络结构。对于（CrSi H）二聚体和[CrSi H]（CrSi H）三聚体结构，我们说明，这种聚集体保存高自旋矩的掺杂剂原子，因此是最有吸引力的候选人集群组装材料具有独特的磁性。该研究表明，在双桥键合结构和所获得的聚集体的高热力学稳定性内的单个内笼的结构完成对于通过受控脱氢的潜在合成聚合路线是至关重要的。
Density-functional theory based global geometry optimization is used to scrutinize the possibility of using endohedrally doped hydrogenated Si clusters as building blocks for constructing highly magnetic materials. In contrast to the known clathrate-type facet-sharing, the clusters exhibit a predisposition to aggregation through double Si-Si bridge bonds. For the prototypical CrSi₂₀H₂₀ cluster we show that reducing the degree of hydrogenation may be used to control the number of reactive sites to which other cages can be attached, while still preserving the structural integrity of the building block itself. This leads to a toolbox of CrSi₂₀H(20-2n) monomers with different number of double "docking sites", that allows building network architectures of any morphology. For (CrSi₂₀H₁₈)₂ dimer and [CrSi₂₀H₁₆](CrSi₂₀H₁₈)₂ trimer structures we illustrate that such aggregates conserve the high spin moments of the dopant atoms and are therefore most attractive candidates for cluster-assembled materials with unique magnetic properties. The study suggests that the structural completion of the individual endohedral cages within the doubly bridge bonded structures and the high thermodynamic stability of the obtained aggregates are crucial for potential synthetic polimerization routes via controlled dehydrogenation.