论文标题
丁二烯纳米簇在石墨中的堆叠介导的扩散
Stacking-Mediated Diffusion of Ruthenium Nanoclusters in Graphite
论文作者
论文摘要
对于工程和纳米技术中的各种石墨应用，金属原子掺杂剂的扩散，穿透和插入是一个重要问题。我们已经对石墨烯单层上的氟纳米簇的行为进行了系统的第一原理计算，并插入了双层。我们的计算结果表明，在足够高的单个RU原子间隙密度下，插入的原子可以将周围的晶格剪切到AA堆叠构型，这种效果随着群集大小的增加而削弱。此外，层间堆叠配置反过来对群集扩散有重大影响。因此，我们发现扩散率的不同趋势是聚类大小和层间堆叠的函数。对于单层石墨烯和AA石墨烯双层，小簇的形成通常会降低扩散屏障，而对于首选的AB堆叠构型而言，相反的行为是相反的。这些结果表明，局部杂质浓度和层间疏松的条件能够调节金属杂质在石墨中的扩散性。
The diffusion, penetration and intercalation of metallic atomic dopants is an important question for various graphite applications in engineering and nanotechnology. We have performed systematic first-principles calculations of the behaviour of ruthenium nanoclusters on a graphene monolayer and intercalated into a bilayer. Our computational results show that at a sufficiently high density of single Ru atom interstitials, intercalated atoms can shear the surrounding lattice to an AA stacking configuration, an effect which weakens with increasing cluster size. Moreover, the interlayer stacking configuration, in turn, has a significant effect on cluster diffusion. We therefore find different trends in diffusivity as a function of cluster size and interlayer stacking. For monolayer graphene and an AA graphene bilayer, the formation of small clusters generally lowers diffusion barriers, while the opposite behaviour is found for the preferred AB stacking configuration. These results demonstrate that conditions of local impurity concentration and interlayer disregistry are able to regulate the diffusivity of metallic impurities in graphite.
