Аннотация:In-plane heterostructures of hexagonal boron nitride (h-BN) and graphene(Gr) have recently appeared in the focus of material science research owing to theirintriguing and tunable electronic properties. However, disclosure of the atomic structureand properties of one-dimensional heterojunctions between Gr and h-BN domainsremains a largely unexplored and challenging task. Here, we report an approach to obtain aperfectly 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 Grand h-BN on the close-packed Co surface. High crystalline quality of the resulting interfaceallowed 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.