Extended Data Fig. 2: Analysis of the reduced radial distribution function obtained from the electron diffraction data and cross-sectional chemical mapping of the a-BN film.

a, Azimuthally averaged experimental electron diffraction intensity of a-BN. b, Reduced radial distribution function, G(r), of a-BN obtained from the electron diffraction data. The peak position r = 1.44 Å corresponds to the nearest-neighbour distance of B–N. The G(r) curve was calculated using eRDF Analyser (an open-source interactive GUI for electron reduced density function analysis). c, High-angle annular dark-field (HAADF) scanning TEM image (left) overlaid with EDS maps of carbon (red), nitrogen (green) and silicon (blue). An image with overlaid EDS maps for all elements is shown on the right. Scale bars, 20 nm.