Pseudo-Polymorphism in Layered FeS Intercalates: A Competition between Charged and Neutral Guest Species
Pseudo-Polymorphism in Layered FeS Intercalates: A Competition between Charged and Neutral Guest Species
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DOI：
10.1021/acs.chemmater.2c00270
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发表时间：
2022-06
影响因子：
8.6
通讯作者：
Colin P. Harmer;S. Kamali;O. Lebedev;Shannon J. Lee;R. Ribeiro;P. Canfield;K. Kovnir
中科院分区：
文献类型：
--
作者：
Colin P. Harmer;S. Kamali;O. Lebedev;Shannon J. Lee;R. Ribeiro;P. Canfield;K. Kovnir
通过系统的合成研究，合成了一种新的四面体FeS-乙二胺插层化合物[Fe 9.4（2）S10][Fe（en）3]0.6（1）·en 0.9（3）。元素组成，分解行为，高分辨率同步辐射X-射线衍射和总散射，57 Fe Mo穆斯堡尔谱和电子衍射的协同组合的基础上确定的组合物和复杂的晶体结构。通过与文献报道的[Fe 8 S10][Fe（en）3]1·en 0. 5和四氢FeS的结构进行系统比较，推导出了结构模型。新化合物具有平坦的Fe_（9.4）S_（10）层，类似于超导二元FeS中的层。在[Fe（en）3]0.6·en 0.9的晶体结构中，[Fe（en）3]2+配合物和中性乙二胺分子以约2：3的比例占据层间空间。层间物种不是随机取向的，但有序的高分辨率X-射线衍射和电子衍射图案中的超结构衍射峰证明。磁性研究表明，在低于2K的温度下没有超导转变，表明[Fe（en）3]0.6·en 0.9中Fe-S层中微量（约6%）铁空位的存在仍然足以使费米能级的位置发生移动，从而导致性能的调整。我们的工作表明了详细表征插层化合物的晶体结构的重要性，以了解所观察到的性质的起源和发展适当的结构-性质关系。
Systematic synthesis studies of the formation of tetrahedral FeS-ethylenediamine intercalates resulted in the synthesis of a new compound, [Fe9.4(2)S10][Fe(en)3]0.6(1)·en0.9(3). The composition and complex crystal structure were determined based on a synergistic combination of elemental composition, decomposition behavior, high-resolution synchrotron X-ray diffraction and total scattering,57Fe Mössbauer spectroscopy, and electron diffraction. The structural model was derived based on a systematic comparison to the previously reported structures [Fe8S10][Fe(en)3]1·en0.5and tetragonal FeS. The new compound has flat Fe9.4S10layers, analogous to those in superconducting binary FeS. In the crystal structure of [Fe9.4S10][Fe(en)3]0.6·en0.9, the interlayer space is occupied by [Fe(en)3]2+complexes and neutral ethylenediamine molecules in a ∼2:3 ratio. Interlayer species are not randomly oriented but ordered as evidenced by superstructural diffraction peaks in both high-resolution X-ray diffraction and electron diffraction patterns. Magnetic studies reveal no superconducting transition down to 2 K, indicating that the presence of minute amounts (∼6%) of iron vacancies at the Fe-S layer in [Fe9.4S10][Fe(en)3]0.6·en0.9is still sufficient to shift the position of the Fermi level resulting in an adjustment of the properties. Our work shows the importance of detailed characterization of the crystal structure of intercalated compounds to understand the origin of the observed properties and develop proper structure–property relationships.