论文标题
菱形石墨中的双回应拉曼带的多共鸣拉曼带的多激发研究
Multiple-excitation study of the double-resonance Raman bands in rhombohedral graphite
论文作者
论文摘要
双共振（DR）拉曼过程是所有SP2碳材料的签名，并提供了石墨烯，碳纳米管和不同石墨型材料中电子结构和声子分散的基本信息。在这项工作中，我们使用五个不同的激发激光能量对不同的Raman Raman Dr Raman带的研究进行了研究，并通过更改激光能量来获得不同DR特征的分散。将结果与Bernal石墨的结果进行了比较，并表明菱形石墨表现出更丰富的Raman频谱。例如，菱形石墨的2D带更宽，由几种表现出不同的分散行为的最大值组成。菱形石墨中更多的DR条件的发生归因于以下事实：其Brillouin区（BZ）的体积是Bernal BZ的两倍，从而允许更多的通道用于共振条件。与Bernal石墨相比，Intervalley To-La to-la带的光谱在2450 cm-1的特征上也越来越丰富。还出现了涉及声和光子声子的不同插图过程的光谱区域1700-1850 cm-1的结果和分析。
The double-resonance (DR) Raman process is a signature of all sp2 carbon material and provide fundamental information of the electronic structure and phonon dispersion in graphene, carbon nanotubes and different graphite-type materials. We have performed in this work the study of different DR Raman bands of rhombohedral graphite using five different excitation laser energies and obtained the dispersion of the different DR features by changing the laser energy. Results are compared with those of Bernal graphite and shows that rhombohedral graphite exhibit a richer DR Raman spectrum. For example, the 2D band of rhombohedral graphite is broader and composed by several maxima that exhibit different dispersive behavior. The occurrence of more DR conditions in rhombohedral graphite is ascribed to the fact that the volume of its Brillouin zone (BZ) is twice the volume of the Bernal BZ, allowing thus more channels for the resonance condition. The spectra of the intervalley TO-LA band of rhombohedral graphite, around 2450 cm-1, is also broader and richer in features compared to that of Bernal graphite. Results and analysis of the spectral region 1700-1850 cm-1, where different intravalley processes involving acoustic and optical phonons occurs, are also presented.
