In situ unravelling structural modulation across the charge-density-wave transition in vanadium disulfide.
In situ unravelling structural modulation across the charge-density-wave transition in vanadium disulfide.
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DOI：
10.1039/c5cp01326g
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
Xu Sun;T. Yao;Zhenpeng Hu;Yuqiao Guo;Qinghua Liu;Shiqiang Wei;Changzheng Wu
中科院分区：
文献类型：
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作者：
Xu Sun;T. Yao;Zhenpeng Hu;Yuqiao Guo;Qinghua Liu;Shiqiang Wei;Changzheng Wu
深入理解电荷密度波（CDW）跃迁中电子有序和结构有序之间的关系对于基础研究和技术应用都至关重要。在此，我们使用原位X射线吸收精细结构（XAFS）光谱结合高分辨透射电子显微镜（HRTEM），我们已经说明了在整个CDW转变的局部结构演变的原子水平的信息及其对VS 2系统的本征电学性质的影响。在整个CDW过程中清楚地观察到了结构转变，这通过V-V键长（ΔR = 0.10 π）的衍生物的钒三聚体的形成而突出。实验结果和理论分析表明，钒三聚体的引入使空间电荷密度分布向周期性方向变形，a1 g带的电导率降低了一半.这些观察结果直接揭示了晶格演化和电子性质变化之间的密切联系，为理解VS 2系统和其他同构过渡金属二硫属化物在CDW转变过程中电子-晶格相互作用的内在本质铺平了新的途径。
A deep understanding of the relationship between electronic and structure ordering across the charge-density-wave (CDW) transition is crucial for both fundamental study and technological applications. Herein, using in situ X-ray absorption fine structure (XAFS) spectroscopy coupled with high-resolution transmission electron microscopy (HRTEM), we have illustrated the atomic-level information on the local structural evolution across the CDW transition and its influence on the intrinsic electrical properties in VS2 system. The structure transformation, which is highlighted by the formation of vanadium trimers with derivation of V-V bond length (ΔR = 0.10 Å), was clearly observed across the CDW process. Moreover, the corresponding influence of lattice variation on the electronic behavior was clearly characterized by experimental results as well as theoretical analysis, which demonstrated that vanadium trimers drive the deformation of space charge density distribution into √3 ×√3 periodicity, with the conductivity of a1g band reducing by half. These observations directly unveiled the close connection between lattice evolution and electronic property variation, paving a new avenue for understanding the intrinsic nature of electron-lattice interactions in the VS2 system and other isostructural transition metal dichalcogenides across the CDW transition process.