Atomic structural analysis of a monolayer epitaxial film of hexagonal boron nitride/Ni(111) studied by LEED intensity analysis

The atomic structure of a monolayer epitaxial film of hexagonal boron nitride (h-BN) formed on a Ni(111) surface was investigated by means of LEED intensity analysis. We measured the I-V curves of the (1,0), (0,1) and (1,1) diffraction spots from a 1 × 1 atomic structure, and analyzed them by using Van Hove's analytical program based on dynamical theory. Six different atomic structural models meeting the experimental requirement of the 3-m symmetry were evaluated with Pendry's reliability factor. The final best-fit structure characterized by the minimum Pendry's reliability factor of 0.27 is as follows; the nitrogen atom in a unit cell of the h-BN overlayer is located at the on-top site of the topmost Ni atoms, while the boron atom exists at the fcc-hollow site. The spacings between the nitrogen (boron) atom and the topmost Ni layer is 2.04 Å (2.2 Å) , which is much narrower than the interlayer spacing in bulk h-BN (3.33 Å).