Stability of BN/metal interfaces in gaseous atmosphere

Hexagonal boron nitride (h-BN) is often prepared by epitaxial growth on metals, and stability of the formed BN/metal interfaces in gaseous environment is a key issue for physicochemical properties of the BN overlayers. As an illustration here, the structural change of a BN/Ru(0001) interface upon exposure to O₂ has been investigated using in situ photoemission electron microscopy (PEEM) and ambient pressure X-ray photoelectron spectroscopy (AP-XPS). We demonstrate the occurrence of oxygen intercalation of the BN overlayers in O₂ atmosphere, which decouples the BN overlayer from the substrate. Comparative studies of oxygen intercalation at BN/Ru(0001) and graphene/Ru(0001) surfaces indicate that the oxygen intercalation of BN overlayers happens more easily than graphene. This finding will be of importance for future applications of BN-based devices and materials under ambient conditions.