Formation of single layer h-BN on Pd(1 1 1)

The structure of hexagonal boron nitride (h-BN) on Pd(1 1 1) was studied with low energy electron diffraction (LEED), photoelectron spectroscopy and scanning tunnelling microscopy (STM). h-BN forms flat monolayers on the Pd(1 1 1) surface in contrast to Rh(1 1 1) where a complex self-assembled double layer structure, the nanomesh [M. Corso, W. Auwärter, M. Muntwiler, A. Tamai, T. Greber, J. Osterwalder, Science 303 (2004) 217], appears. The LEED patterns reveal a dominating 10 × 10 h-BN superstructure, with a second, distinct structure rotated by 30° and further azimuthally randomly oriented h-BN overlayers. This is consistent with STM images which show several different Moiré patterns associated with different rotation angles of the overlayer. Additionally the use of thin Pd(1 1 1) films instead of single crystal substrates was studied. No significant differences in the h-BN film quality were found.