  The thickness and interfacial geometry of hexagonal boron nitride (hBN) films
grown by chemical vapor deposition on polycrystalline nickel foils is studied
using low-energy electron microscopy (LEEM). The reflectivity of the electrons,
measured over an energy range of 0 - 20 eV, reveals distinct minima and maxima.
The measured data is compared with simulations based on a first-principles
description of the electronic structure of the material. From this comparison,
the number of hBN layers and the separation between the lowest hBN layer and
the nickel surface is deduced. The coupling of interlayer states of the hBN to
both image-potential and Shockley-type surface states of the nickel is
discussed, and the dependence of the reflectivity spectra on the surface
orientation of nickel grains is examined.
