QUANTITATIVE HREM USING NONLINEAR LEAST-SQUARES METHODS

Non-linear least-squares methods have been coupled with high-resolutio n image simulation to determine the critical electron microscopic imag ing parameters, such as thickness and defocus, from an experimental im age. The method has been extended to include the optimization of atomi c column positions to determine atomic structure. As an example, the m ethod has been applied to the refinement of the atomic structure of a Sigma 5(310)/[001] grain boundary in Nb.