De-intercalation process from Stage -1 to Stage -2 graphite intercalation compounds revisited
De-intercalation process from Stage -1 to Stage -2 graphite intercalation compounds revisited
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重新审视从阶段-1到阶段-2石墨插层化合物的脱嵌过程
DOI：
10.1002/pssb.201200174
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Chacón-Torres J
中科院分区：
文献类型：
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作者：
Chacón-Torres J
第 1 阶段和第 2 阶段石墨插层化合物 (GIC) 中 G 线拉曼响应中存在的不同声子的识别和贡献对于正确的阶段确定至关重要。激光诱导脱嵌等不同因素在这些相的精确阶段分配及其固有拉曼响应中发挥着重要作用。在这篇文章中，原位显微拉曼分析是在高真空条件下进行的。使用高激光功率（8.5 mW）引起样品的局部加热，以研究从 Stage-1 到 Stage-2 GIC 的脱嵌过程。根据记录的光谱进行详细的拉曼线形分析，以确定 KC8、CaC6 和 LiC6 的 G 线响应的变化。我们确认了 ∼1510 cm−1 处的宽 E2gFano 模式与 GIC 中固有的 Stage-1 拉曼响应的分配。此外，从 Stage-1 到 Stage-2 最明显的变化是在 1565–1610cm−1 范围内的非对称 Fano 模式中观察到的。该模式与石墨的一阶拉伸拉曼模式相关，该模式随着脱嵌的函数而趋向于频率增加和宽度减小。最后，脱嵌后Stage-2相的响应被证实是识别高掺杂GIC中插层阶段的有用基准。
The identification and contribution of the different phonons present in the G‐line Raman response inStage‐1 andStage‐2 graphite intercalation compounds (GIC) is crucial for a correct stage determination. Different factors like laser induced de‐intercalation play an important role in the precise stage assignment of these phases, and their intrinsic Raman response. In this contribution, anin situmicro‐Raman analysis was conducted under high‐vacuum conditions. Local heating of the samples was induced by using a high laser power (8.5 mW) in order to study the de‐intercalation process fromStage‐1 toStage‐2 GICs. A detailed Raman line‐shape analysis was performed from the recorded spectra to determine the changes from the G‐line response of KC8, CaC6, and LiC6. We confirmed the assignment of the broad E2gFano mode at ∼1510 cm−1to the intrinsicStage‐1 Raman response in GICs. Additionally, the most evident change fromStage‐1 toStage‐2 was observed in an asymmetric Fano mode in the range of 1565–1610 cm−1. This mode is linked to the first‐order stretching Raman mode of Graphite, which tends to increase in frequency and decrease in width as function of de‐intercalation. Finally, the response of theStage‐2 phase after de‐intercalation was confirmed to be a useful benchmark for the identification of the intercalation stage in highly doped GICs.