Nucleation of c-BN on hexagonal boron nitride - art. no. 184107

The nucleation of cubic boron nitride (c-BN) on the zigzag edges (100) and (<(1)00over bar>100), as well as on the armchair edge (110) of the basal (0 01) plane of hexagonal BN (h-BN) has been theoretically investigated, using a cluster approach and the density-functional theory. The total energy of the different buckled (cubic and wurtzitic) outgrowths from the edge atoms has then been related to the total energy of the corresponding planar (hexa gonal) counterparts. The different outgrowths, as well as the various types of edge atoms, were all terminated with H or F atoms. For the zigzag edges it was shown that the nucleation of c-BN is the energetically most favorab le one in an H- or F-rich environment. On the armchair edge, however, the n ucleation of wurtzitic BN(w-BN) was even more energetically preferred. Furt hermore. it was shown that the F atoms possess a significantly larger abili ty to stabilize the c-BN nuclei than do the H atoms.