Nanostructural and Microstructural Ordering and Thermoelectric Property Tuning in Misfit Layered Sulfide [(LaS)x]1.14NbS2
Nanostructural and Microstructural Ordering and Thermoelectric Property Tuning in Misfit Layered Sulfide [(LaS)x]1.14NbS2
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DOI：
10.1021/acs.chemmater.5b03365
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发表时间：
2015-11
影响因子：
8.6
通讯作者：
P. Jood;M. Ohta;O. Lebedev;D. Berthebaud
中科院分区：
文献类型：
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作者：
P. Jood;M. Ohta;O. Lebedev;D. Berthebaud
在失配层状系统中控制纳米尺度结构有序的潜力可以为在这些系统中实现高热电性能开辟新的途径。在目前的工作中，我们证明，成分的变化可以提供纳米级的调整失配分层（LaxSx）1.14NbS2（x = 0.90，0.95，1.00，1.05，1.10），从而改善热电性能（在300至950 K的温度范围内进行研究）。通过CS2硫化制备样品，并使用压力辅助烧结进行固结。通过透射电子显微镜分析表明，非化学计量促进了层的长程有序，并导致细长的薄片形成。La缺乏x = 0.95的样品被发现包含大的应变引起的堆垛无序，由于该长的片层卷起形成管状结构，而La丰富x = 1.05的样品具有更有序的结构，并且观察到片层边缘仅轻微卷曲。结构改良
The potential to control the structural ordering at the nanoscale in misfit layered systems can open new paths for achieving high thermoelectric performance in these systems. In the present work, we demonstrate that compositional changes can provide nanoscale tuning in misfit layered (LaxSx)1.14NbS2 (x = 0.90, 0.95, 1.00, 1.05, 1.10), leading to improved thermoelectric properties (investigated over the temperature range of 300 to 950 K). The samples were prepared by CS2 sulfurization and consolidated using pressure-assisted sintering. It was revealed through transmission electron microscopy analysis that nonstoichiometry promotes long-range ordering of the layers and results in elongated lamella formations. The La deficient x = 0.95 sample was found to contain large strain induced stacking disorder, owing to which the long lamellas rolled up to form tubular structures, whereas the La rich x = 1.05 sample had a much ordered structure and only slight curling of lamella edges was observed. Improved structura...