STM INVESTIGATION OF SINGLE LAYER GRAPHITE STRUCTURES PRODUCED ON PT(111) BY HYDROCARBON DECOMPOSITION
STM INVESTIGATION OF SINGLE LAYER GRAPHITE STRUCTURES PRODUCED ON PT(111) BY HYDROCARBON DECOMPOSITION
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DOI：
10.1016/0039-6028(92)90183-7
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发表时间：
1992-03-15
期刊：
影响因子：
1.9
通讯作者：
COMSA, G
中科院分区：
文献类型：
--
作者：
LAND, TA;MICHELY, T;COMSA, G
扫描隧道显微镜对碳氢化合物分解在铂(111)表面形成的石墨层的形核、生长和性质提供了新的见解。将被乙烯覆盖的表面加热到800K会形成小的(直径约20-30埃)石墨岛，它们最初均匀地分布在表面上。在1000K以上进一步退火，可以观察到石墨的积累，在较低的台阶边缘形成一层，并在梯田上形成大的规则形状的岛。已确定在高温下烃类分解导致在铂表面形成单层石墨层。有趣的是，在这一单层石墨的扫描隧道显微镜图像中，只有石墨晶格中的六个碳原子中的三个是可见的。这一结果不能用通常用大块石墨表面的不等价碳原子给出的解释来解释。在石墨区有明显的周期变化到22埃的超结构，这是由于石墨和铂晶格在不同的相对旋转下具有更高的阶公度性。
STM has provided new insight into the nucleation, growth and nature of the graphite layer formed on Pt(111) by hydrocarbon decomposition. Annealing an ethylene covered surface to 800 K results in the formation of small (about 20-30 angstrom in diameter) graphite islands which are initially uniformly distributed over the surface. With further annealing above 1000 K, the graphite is observed to accumulate, forming a layer at the lower step edges and also forming large, regularly shaped islands on the terraces. It has been determined that hydrocarbon decomposition at elevated temperatures results in formation of a single layer of graphite on the Pt surface. It is interesting to note that in the STM images of this single layer of graphite only three of the six carbon atoms in the graphite lattice are visible. This result cannot be accounted for by the usual explanation given in terms of inequivalent carbons atoms for the bulk graphite surface. Superstructures with periodicities varying up to 22 angstrom are evident on the graphite areas and are due to a higher order commensurability of the graphite and Pt lattices at different relative rotations.