The imaging equations for high resolution electron microscopy are analysed using an approach based upon expanding the electron wave as positionally modulated diffraction beams. A high-order semi-linear approximation is derived which includes the leading non-linear effects of a reciprocal space integration and can be conveniently expressed in real space. This allows a direct visualisation of imaging effects in real space using a conventional wave dispersion approach. Based on this, the primary sources of lattice fringe artifacts and errors in the 2 1 2D technique are briefly discussed, and an experimental technique for guarding against them employing dark field imaging is described.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics