BC _x layers with honeycomb lattices on an NbB ₂(0001) surface

At elevated temperatures of 1000-1500K, carbon (C) atoms that segregated to a surface and mixed with the boron (B) honeycomb lattice resulted in the formation of three different BC _x layers as the topmost layers of NbB ₂(0001). Two of the layers were commensurate lattices: and structures; the third was incommensurate. The characteristic features of the lattice with a honeycomb structure are discussed on the basis of the experimental data.