▎ 摘　　要

The interfacial interactions between graphene and alpha-alumina with several crystal orientations are systematically studied by first-principles calculations and in-situ experiments. It is found that the alumina surfaces of (0001), (1012), (1011), (1010), and (1102) in these interfaces with the graphene (0001) surface do not undergo obvious geometric reconstruction, while the interlayer gap of multilayer graphene at the interface with the (1011) alumina surface shrinks obviously. In terms of interface stability, the interface with the (1102) alumina surface is the most stable, while the interface with the (1011) surface is the least energy favorable among all the studied interfaces. Additionally, there is no strong correlation between alumina surface energy and interface energy. To verify the results of theoretical calculations, the graphene/alumina interface samples and composites were synthesized. The in-situ high-resolution spherical aberration electron microscope observation as well as Raman stress analysis were performed. It is confirmed that the interface composed of (1102) surface can indeed exist stably. The factors affecting the interface stability were further investigated by analyzing the local electron density of states. It is found that the strength of interfacial electronic interaction is directly related to the stability of the interface. The results suggest a new possible mechanism that electronic interactions and van der Waals forces jointly affect the stability of the interface between graphene and alpha-alumina ceramics.