Ultralow thermal conductivity in the quaternary semiconducting chalcogenide Cs4[Ho26Cd7Se48] with an unprecedented closed cavity architecture
Ultralow thermal conductivity in the quaternary semiconducting chalcogenide Cs4[Ho26Cd7Se48] with an unprecedented closed cavity architecture
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DOI：
10.1039/d0qi01240h
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发表时间：
2021-02
影响因子：
7
通讯作者：
Hong Chen;Peng-Fei Liu;Hua Lin;Xintao Wu
中科院分区：
文献类型：
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作者：
Hong Chen;Peng-Fei Liu;Hua Lin;Xintao Wu
新型的三维无机硫属化合物结构由于其丰富的结构组装模式和有趣的物理性质而引起了人们的广泛关注。本文中，发现了四种同构的四元半导体硫属化物，即Cs 4 [RE 26 Cd 7Se 48]（RE = Ho，Er，Tm和Lu），并且发现它们在四元体系中结晶，空间群为I41/a（no.88）。它们的结构特征是由[RESe 6]和[MSe 6]（M = RE/Cd）八面体共边共面形成的3D准NaCl型结构，其中嵌入了前所未有的聚阴离子[Cs2@Se18-Cd-Cs2@ Se 18]封闭腔。值得注意的是，化合物Cs4[Ho 26 Cd 7Se 48]在295 K至675 K范围内表现出超低热导率（0.38-0.29 W m-1 K-1），这是晶体硫属化物中报道的最低值之一。这一结果不仅丰富了主客体体系的配位化学，而且为设计新型低热导率无机硫属化合物提供了新的思路。
Novel three-dimensional (3D) inorganic chalcogenide architectures have attracted much attention because of their rich structural assembly patterns and intriguing physical properties. Herein, four isostructural quaternary semiconducting chalcogenides, namely Cs4[RE26Cd7Se48] (RE = Ho, Er, Tm, and Lu), have been discovered and found to crystallize in a tetragonal system, space group I41/a (no. 88). Their structures feature 3D quasi-NaCl type architectures formed by edge-sharing and face-sharing of [RESe6] and [MSe6] (M = RE/Cd) octahedra, which are embedded with the unprecedented polyanionic [Cs2@Se18–Cd–Cs2@Se18] closed cavities. Significantly, the compound Cs4[Ho26Cd7Se48] exhibits ultralow thermal conductivity (0.38–0.29 W m−1 K−1) from 295 K to 675 K, which is one of the lowest values reported in crystalline chalcogenides. This result not only enriches the coordination chemistry of host–guest systems, but also suggests a new thought for the design of novel inorganic chalcogenides with intrinsic low thermal conductivities.