The accuracy with which atomic positions might be determined by means of high-resolution electron microscopy has been investigated. Extensive calculations have been undertaken for a 1D model structure as a function of various factors, including resolution, atomic separation, focus and incident beam alignment. These reveal that experimental shifts of up to 30 pm may be encountered even near optimum focus with axial imaging conditions. Full 2D multislice calculations for a recurrent intergrowth structure have broadly confirmed these results. It is concluded that compensation of the imaging conditions by digital focal series restoration must be undertaken before accurate atomic positions can be deduced from micrographs with any reliability.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics