Incomplete Bilayer Termination of the Ice (0001) Surface
Incomplete Bilayer Termination of the Ice (0001) Surface
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DOI：
10.1021/acs.jpcc.5b10836
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发表时间：
2016-01-21
影响因子：
3.7
通讯作者：
Morgenstern, Karina
中科院分区：
文献类型：
--
作者：
Bockstedte, Michel;Michl, Anja;Morgenstern, Karina
完整的双层通常被认为是六方冰的（0001）表面的终止。在 Cu(111) 上生长的薄晶冰结构的实验证明了双层顶部的分子结构的终止。复杂的分子末端建模（包括密度泛函理论中的分子簇和装饰六角形箭头）与高分辨率 STM 成像相结合，进行结构分析，并揭示造成明显区别的可能原因。在 130 K 的短暂退火过程中出现的主要分子结构被确定为水二聚体和三聚体的排列。通过组合方法，导出了装饰六边形箭头的详细模型。这种结构具有低能量；然而，质子有序双层在小范围内更有利。然而，能量上不利的水键合（例如，在薄冰膜中）可能会驱动分子末端的形成，其中动力学效应仍然是一个重要因素。研究结果还揭示了双层岛的边缘终止。
The complete bilayer is commonly considered as the termination of the (0001) surface of hexagonal ice. Experiments on thin crystalline ice structures grown on Cu(111) demonstrated a termination by admolecule structures on top of the bilayer. Modeling of complex admolecule terminations including admolecule clusters and decorated hexagon adrows within density functional theory and high-resolution STM imaging are combined for the structural analysis and to reveal possible causes for the apparent distinction. A dominant admolecule structure that appears during a short anneal at 130 K is identified as an arrangement of water dimer and trimers. By the combined approach, detailed models for decorated hexagon adrows are derived. Such structures possess low energy; however, the proton-ordered bilayer is more favorable at a small margin. Yet, energetically unfavorable bonding of water, for example, in thin ice films may drive the formation of admolecule terminations, for which kinetic effects still are an important factor. The results also shine light on the edge termination of bilayer islands.