Growth of two-dimensional metals has eluded materials scientists since the discovery of the atomically thin graphene and other covalently bound 2D materials. Here, we report a two-atom-thick hexagonal copper-gold alloy, grown through thermal evaporation on freestanding graphene and hexagonal boron nitride. The structures are imaged at atomic resolution with scanning transmission electron microscopy and further characterized with spectroscopic techniques. While the 2D structures are stable over months in vacuum, electron irradiation in the microscope provides sufficient energy to cause a phase transformation—atoms are released from their lattice sites with the gold atoms eventually forming face-centered cubic nanoclusters on top of 2D regions during observation. The presence of copper in the alloy enhances sticking of gold to the substrate, which has clear implications for creating atomically thin electrodes for applications utilizing 2D materials. Its practically infinite surfac...

中文翻译：

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六方二维金属CuAu

自从发现原子薄的石墨烯和其他共价键合的2D材料以来，二维金属的生长就一直困扰着材料科学家。在这里，我们报告了一种在单个石墨烯和六方氮化硼上通过热蒸发生长的，具有两个原子厚度的六方铜金合金。用扫描透射电子显微镜以原子分辨率对结构成像，并用光谱技术进一步表征。尽管2D结构在真空中可以在数月内保持稳定，但显微镜中的电子辐照提供了足够的能量来引起相变-原子从其晶格位置释放出来，金原子最终在观察过程中在2D区域顶部形成了以面心为中心的立方纳米簇。合金中铜的存在会增强金在基材上的附着力，对于使用2D材料的应用创建原子上薄的电极具有明显的含义。它几乎是无限的...