Atomic-focuser imaging in electron nanodiffraction from carbon nanoshells

When nanodiffraction patterns are obtained by transmission through the top and bottom walls of near-spherical hollow carbon nano-shells, using the foc used probe of a STEM instrument, a graphitic crystal in one wall may act as an atomic focuser to produce high-resolution images of small regions of th e other wall within the central beam and the diffraction disks of the nanod iffraction pattern. A theoretical analysis of the imaging process is given. Images showing one- and two-dimensional periodicities, with fringe spacing s as small as 0.124 nm, and also images showing non-periodic features have been obtained from carbon nanoshells having diameters of the order of 100 n m. (C) 2000 Elsevier Science B.V. All rights reserved.