Epitaxial growth of hexagonal boron nitride on Ag(111)

The epitaxial growth of hexagonal boron nitride on a Ag(111) surface by chemical vapor deposition of borazine (HBNH)3 and trichlorborazine (ClBNH)3 is investigated by X-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED). In contrast to other transition-metal surfaces of hexagonal symmetry, such as Ni(111), Rh(111), or Ru(0001), the hexagonal BN layers form domains of arbitrary orientation, independent on the precursor. This indicates that - with respect to the Ag(111) lattice - there is no preferred direction for the growth of BN. These results are in accordance with recent ab initio calculations that predict vanishing or at least very weak bonding energies for BN on (111) surfaces of noble metals.