The use of a field emission gun (FEG) in high resolution TEM (HRTEM) improves the information limit much below the point resolution. In the area between point and information resolution of the FEG-TEM, image interpretation is complicated by the lens aberrations and focus effects. Different reconstruction algorithms can be used depending on the assumptions that are made in the HRTEM imaging model. First, the 'paraboloid method' (PAM) aims at filtering out recursively the nonlinear contributions in the images. Second, the 'maximum-likelihood' (MAL) where the electron wave at the object's exit plane (object wave) is matched to the measured intensities in the HRTEM images by minimizing a least squares functional, using the steepest descent approach.
|Title of host publication||Proceedings of the 51st Annual Meeting Microscopy Society of America, 1 - 6 August 1993, Cincinnati, Ohio|
|Editors||G.W. Bailey, C.L. Rieder|
|Place of Publication||San Francisco|
|Publisher||San Francisco Press|
|Publication status||Published - 1993|