Molecular beam epitaxial growth of hexagonal boron nitride on Ni(1 1 1) substrate

We demonstrate hexagonal boron nitride (h-BN) epitaxial growth on Ni(1 1 1) substrate by molecular beam epitaxy (MBE) at 890 °C. Elemental boron evaporated by an electron-beam gun and active nitrogen generated by a radio-frequency (RF) plasma source were used as the group-III and -V sources, respectively. Reflection high-energy electron diffraction revealed a streaky (1×1) pattern, indicative of an atomically flat surface in the ongoing growth. Correspondingly, atomic force microscopy images exhibit atomically smooth surface of the resulting h-BN film. X-ray diffraction characterization confirmed the crystallinity of the epitaxial film to be h-BN, and its X-ray rocking curve has a full-width at half-maximum of 0.61°, which is the narrowest ever reported for h-BN thin film. The epitaxial alignments between the h-BN film and the Ni substrate were determined to be [0 0 0 1]h−BN∥[1 1 1]Ni, [1 1 2¯ 0]h−BN∥[1¯ 1 0]Ni, and [1 1¯ 0 0]h−BN∥[1¯ 1¯ 2]Ni.