Knol Marvin, Arefi Hadi H, Corken Daniel, Gardner James, Tautz F Stefan, Maurer Reinhard J, Wagner Christian
Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany.
Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany.
Sci Adv. 2021 Nov 12;7(46):eabj9751. doi: 10.1126/sciadv.abj9751. Epub 2021 Nov 10.
The part-by-part assembly of functional nanoscale machinery is a central goal of nanotechnology. With the recent fabrication of an isolated standing molecule with a scanning probe microscope, the third dimension perpendicular to the surface will soon become accessible to molecule-based construction. Beyond the flatlands of the surface, a wealth of structures and functionalities is waiting for exploration, but issues of stability are becoming more critical. Here, we combine scanning probe experiments with ab initio potential energy calculations to investigate the thermal stability of a prototypical standing molecule. We reveal its generic stabilization mechanism, a fine balance between covalent and van der Waals interactions including the latter’s long-range screening by many-body effects, and find a remarkable agreement between measured and calculated stabilizing potentials. Beyond their relevance for the design and construction of three-dimensional molecular devices at surfaces, our results also indicate that standing molecules may serve as tunable mechanical gigahertz oscillators.
功能性纳米级机械的逐个部件组装是纳米技术的核心目标。随着最近利用扫描探针显微镜制造出孤立的直立分子，垂直于表面的第三维将很快可用于基于分子的构建。在表面的平坦区域之外，大量的结构和功能等待探索，但稳定性问题变得更加关键。在这里，我们将扫描探针实验与从头算势能计算相结合，以研究典型直立分子的热稳定性。我们揭示了其通用的稳定机制，即共价相互作用和范德华相互作用之间的精细平衡，包括后者通过多体效应的长程屏蔽，并发现测量和计算的稳定势之间有显著的一致性。除了对表面三维分子器件的设计和构建具有相关性之外，我们的结果还表明直立分子可以用作可调谐的机械千兆赫兹振荡器。
