Oxygen-Etching of h-BN/Ru(0001) Nanomesh on the Nano- and Mesoscopic Scale

The stability of the recently discovered h-BN/Ru(0001) nanomesh is of crucial importance for potential applications as a nanotemplate. In particular, thermal stability in oxygen environment is important for nanocatalysis applications. We report here on the etching experiments of the h-BN layer by molecular oxygen exposure at elevated temperatures. This process is studied both by scanning tunneling microscopy (STM) on a microscopic scale and with in situ low energy electron microscopy (LEEM) on the mesoscopic scale. Temperature thresholds are determined for the microscopic (600 °C) and the mesoscopic (750 °C) etching processes for O 2 pressures up to 1 × 10 −6 mbar. Submonolayer amounts of Au deposited on the h-BN/Ru(0001) nanomesh improve considerably the stability of the h-BN nanomesh against etching by O 2 .