▎ 摘　　要

Monolayer-thick hexagonal boron nitride (h-BN) is grown on graphene on SiC(0001), by exposure of the graphene to borazine, (BH)(3)(NH)(3), at 1100 degrees C. The h-BN films form similar to 2-mu m size grains with a preferred orientation of 30 degrees relative to the surface graphene. Low-energy electron microscopy is employed to provide definitive signatures of the number and composition of two-dimensional planes across the surface. These grains are found to form by substitution for the surface graphene, with the C atoms produced by this substitution, then being incorporated below the h-BN (at the interface between the existing graphene and the SiC) to form a new graphene plane. Published by AIP Publishing.