One of the most important functionalities of the atomically thin insulator hexagonal boron nitride (hBN) is its ability to chemically and electronically decouple functional materials from highly reactive surfaces. It is therefore of utmost importance to uncover its structural properties on surfaces on an atomic and mesoscopic length scale. In this paper, we quantify the relative coverages of structurally different domains of a hBN layer on the Ni(111) surface using low-energy electron microscopy and the normal incidence x-ray standing wave technique. We find that hBN nucleates on defect sites of the Ni(111) surface and predominantly grows in two epitaxial domains that are rotated by ${60}^{\circ }$ with respect to each other. The two domains reveal identical adsorption heights, indicating a similar chemical interaction strength with the Ni(111) surface. The different azimuthal orientations of these domains originate from different adsorption sites of N and B. We demonstrate that the majority ($\approx 70\%$) of hBN domains exhibit a $(\mathrm{N},\mathrm{B})=(\mathrm{top},\mathrm{fcc})$ adsorption site configuration while the minority ($\approx 30\%$) show a $(\mathrm{N},\mathrm{B})=(\mathrm{top},\mathrm{hcp})$ configuration. Our study hence underlines the crucial role of the atomic adsorption configuration in the mesoscopic domain structures of in situ fabricated two-dimensional materials on highly reactive surfaces.

中文翻译：

---

hBN在Ni(111)表面的生长、畴结构和原子吸附位点

原子级薄绝缘体六方氮化硼 (hBN) 最重要的功能之一是它能够以化学和电子方式将功能材料与高反应性表面分离。因此，在原子和介观长度尺度上揭示其表面结构特性至关重要。在本文中，我们使用低能电子显微镜和法向入射 X 射线驻波技术量化了 Ni(111) 表面上 hBN 层结构不同域的相对覆盖率。我们发现 hBN 在 Ni(111) 表面的缺陷位点上成核，并且主要在两个旋转的外延域中生长${60}^{\circ }$相对于彼此。这两个域显示出相同的吸附高度，表明与 Ni(111) 表面的化学相互作用强度相似。这些域的不同方位角方向源自 N 和 B 的不同吸附位点。我们证明大多数（$\approx 70\%$) 的 hBN 域表现出 $(\mathrm{N},\mathrm{乙})=(\mathrm{最佳},\mathrm{联邦通信委员会})$ 吸附位点配置，而少数（$\approx 30\%$) 显示一个 $(\mathrm{N},\mathrm{乙})=(\mathrm{最佳},\mathrm{医管局})$配置。因此，我们的研究强调了原子吸附构型在高反应性表面上原位制造的二维材料的介观域结构中的关键作用。