▎ 摘　　要

The grain boundary (GB) composed of topological defects is likely to form where a merge occurred between two separate grains during the chemical vapor deposition fabrication process of in-planar two-dimensional heterostructural nanomaterials. Here, a systematic investigation regarding the geometrical stability, electronic, and magnetic properties of 3d transition metal (TM)-decorated in-planar graphene/hexagonal boron nitride bicrystalline heterostructure (GBN) was performed. The GGA + U approach is employed as the computation method. We selected a periodical grain boundary consisting of pentagon-heptagon or pentagon-octagon topological defects as the hybrid interface between graphene and h-BN domains, and we considered nine atoms, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu, for the TM addition. The GB was found to be the trapped region for all TM impurities during the adsorption process. The binding strength and charge transfer of adsorbed atoms were remarkably enhanced by the GB local topological defects. The adsorption of all nine TM atoms introduces a transformation from nonmagnetic states of pristine GBN to varying magnetization of TM-GBN. Spin-splitting band structures are found in all TM adsorption systems. Multiple electronic states can be achieved, including spin-polarized half-metallic states, half-semiconductor states, and metallic states. Both the charge injection from TM to GBN substrate and electron rearrangement between s, p, and d orbitals of impurity can work on the rich electronic and magnetic properties. Our findings indicate that it is feasible to obtain peculiar electronic and magnetic properties by surface TM addition, which can increase the utilization of in-planar graphene/h-BN heterostructure in spin-electronic materials and nanomagnet areas.