In-plane heterostructures of hexagonal boron nitride (h-BN) and graphene (Gr) have recently appeared in the focus of material science research owing to their intriguing and tunable electronic properties. However, disclosure of the atomic structure and properties of one-dimensional heterojunctions between Gr and h-BN domains remains a largely unexplored and challenging task. Here, we report an approach to obtain a perfectly oriented and atomically thin hybrid h-BN–Gr heterolayer on the Co(0001) surface. A perfect matching of the lattice parameters ensures an epitaxial growth of both Gr and h-BN on the close-packed Co surface. High crystalline quality of the resulting interface allowed us to uncover the structural and electronic properties of the lateral h-BN/Gr heterojunctions by means of complementary microscopic and spectroscopic techniques. In particular, we established the coexistence of two types of zigzag boundaries made of B–C bonds, while the boundaries with N–C bonds were found to be unfavorable. Observation of spin-polarized edge states at the C-zigzag edges of Gr domains allowed us to determine the atomic structure of C-BN heterojunctions with scanning tunneling microscopy.

中文翻译：

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晶格匹配表面上具有BC边界的杂化h-BN-石墨烯单层

六方氮化硼（h-BN）和石墨烯（Gr）的面内异质结构由于其吸引人的和可调节的电子特性，近来已成为材料科学研究的重点。然而，Gr和h-BN域之间的一维异质结的原子结构和性质的公开仍然是一项艰巨而艰巨的任务。在这里，我们报告了一种在Co（0001）表面上获得取向完美且原子薄的杂化h-BN-Gr杂层的方法。晶格参数的完美匹配确保了在紧密堆积的Co表面上Gr和h-BN都可以外延生长。所得界面的高结晶质量使我们能够通过互补的显微镜和光谱技术揭示横向h-BN / Gr异质结的结构和电子性质。特别是，我们建立了由B–C键构成的两种锯齿形边界的共存，而发现具有N–C键的边界是不利的。观察自旋极化边缘状态的Gr域的C字形边缘使我们能够通过扫描隧道显微镜确定C-BN异质结的原子结构。