Abstract
Recently discovered boron nitride (BN) nanoscale cone particles are shown to consist of an ordered stacking of seamless conical shells. High-resolution transmission electron microscopy and nanobeam electron diffraction allowed the orientation of the BN hexagonal rings to be determined. In all but one case, the results conformed with a model of orderly stacked 240 degrees disclinations, which is the smallest cone geometry ensuring the presence of B-N bonds only. One case of a nanoscale cone constituted of 300 degrees disclinations was found, implying that structures containing line defects of non-B-N bonds may form.