WAVE-FUNCTION RECONSTRUCTION IN HRTEM - THE PARABOLA METHOD

The non-linear parabola method for wave function reconstruction in HRT EM is presented in detail. It consists of an iterative procedure in wh ich the linear and non-linear contributions to HRTEM images of a defoc us series are optimally separated which will allow to benefit from a f ast linear reconstruction scheme in which the non-linear contribution is corrected for in a self-consistent way. The method has proven to be a fast and workable algorithm for quantitative wave function reconstr uction with direct resolution improvement. Results are shown for wave function reconstruction on experimentally acquired defocus series for a 200 keV FEG-TEM with a point-to-point resolution of 0.24 nm. In the reconstructed wave functions the resolution could clearly be enhanced up to 0.14 nm.