Boron nitride on SiC(0001)

The promising properties of heterostructures of 2D materials call for scalable sample production via epitaxy. The authors focus on surface structures obtained in a surfactant atmosphere in which a boron nitride template layer forms on SiC(0001). Remarkably, they find that this template is a hexagonal B${}_{x}$N${}_{y}$ layer, but not high-quality hBN. Experiments with the normal-incidence x-ray standing wave technique and spot-profile analysis low-energy electron diffraction reveal the $R{0}^{\ensuremath{\circ}}$ orientation of the layer, the presence of an unexpected boron buffer layer, and the interlayer distances with sub-Angstrom precision.