论文标题
石墨烯分子有助于富含碳星云的红外带
Graphene Molecules Contributing to the Infrared Bands of Carbon Rich Planetary Nebulae
论文作者
论文摘要
自2010年以来，众所周知，富勒烯C60在星际空间中广泛存在。同样，众所周知，石墨烯是合成富勒烯的原始材料。在这里，我们只是假设石墨烯在空间中的出现。计算石墨烯分子的红外光谱是与天文观测光谱和实验室实验相比。用于DFT计算的模型分子是通过一个天文假设选择的，即C13，C24和C54的电荷中性石墨烯，结果C12，C23和C53。他们在六角形网络中有一个碳五角形环。不同的空隙位置被归类为不同的物种。单个空隙被3个自由基碳包围，持有6旋转。自旋状态会影响分子构型和振动光谱。三胞胎状态比单线稳定令人惊讶。大部分电荷中性和三重态自旋状态物种与观察到的富含碳的星云TC1和Lin49的光谱非常相似。我们可以在18.9千分尺处分配主要带，并在6.6、7.0、7.6、8.1、8.5、9.0和17.4千分尺处分配子频段。有趣的是，这些石墨烯种也被分配在激光诱导的碳等离子体的实验室实验中，这些实验是空间中碳簇的类比。结论是，石墨烯分子可能有可能有助于富含碳星云的红外发射带。
It is well known since 2010 that fullerene C60 is widespread through the interstellar space. Also, it is well known that graphene is a source material for synthesizing fullerene. Here, we simply assume the occurrence of graphene in space. Infrared spectra of graphene molecules are calculated to compare both to astronomical observational spectra and to laboratory experimental one. Model molecules for DFT calculation are selected by one astronomical assumption, that is, single void in charge neutral graphene of C13, C24 and C54, resulting C12, C23 and C53. They have a carbon pentagon ring within a hexagon network. Different void positions are classified as different species. Single void is surrounded by 3 radical carbons, holding 6 spins. Spin state affects molecular configuration and vibrational spectrum. It was a surprise that the triplet state is stable than the singlet. Most of charge neutral and triplet spin state species show closely resembling spectra with observed one of carbon rich planetary nebulae Tc1 and Lin49. We could assign major bands at 18.9 micrometer, and sub-bands at 6.6, 7.0, 7.6, 8.1, 8.5, 9.0 and 17.4 micrometer. It is interesting that those graphene species were also assigned in the laboratory experiments on laser-induced carbon plasma, which are analogies of carbon cluster creation in space. The conclusion is that graphene molecules could potentially contribute to the infrared emission bands of carbon-rich planetary nebulae.
