Symmetry versus Commensurability: Epitaxial Growth of Hexagonal Boron Nitride on Pt(111) From B-Trichloroborazine (ClBNH)₃

The growth of hexagonal boron nitride ( h -BN) on a Pt(111) surface by decomposition of B-trichloroborazine (ClBNH) 3 leads to two different sets of domain structures as indicated by low-energy electron diffraction (LEED). In addition to a domain structure, for which the top, hcp, and fcc sites of the substrate lattice are occupied by the BN lattice, there is a new type of domain structure with B and N alternatingly occupying the top and bridge sites of the Pt(111) substrate, a structural motif which has not been observed so far. The new domain structures are a result of the precursor chemistry (B-trichloroborazine vs borazine) as well as the lattice mismatch of the substrate [Pt(111) vs h -BN; mismatch ∼11%].