Electronic Structure of Monolayer Hexagonal Boron Nitride Physisorbed on Metal Surfaces

By using angle-resolved electron spectroscopic methods, we have investigated a monolayer film of hexagonal boron nitride ($h$-BN) epitaxially formed on Ni(111), Pd(111), and Pt(111). The electronic structure of the monolayer $h$-BN is almost independent of the substrate, which is in striking contrast with the case of monolayer graphite [A. Nagashima et al., Phys. Rev. B 50, 4756 (1994)]. The comparison of the present data with those for typical physisorbed systems indicates physisorption of the BN film.