Composition analysis of coherent nanoinsertions of solid solutions on the basis of high-resolution electron micrographs

A program package is presented, ensuring fast direct and inverse Fourier transformations of images, various methods of noise filtration and use of spectral windows, and determination of local interplanar spacings (LIS) from cross-sectional high-resolution electron micrographs. The algorithm for determining the LIS consists in obtaining, by double fast Fourier transformation, a high-resolution image filtered by selecting an appropriate combination of reflections and using this image to find the characteristic LIS. A specific feature of this algorithm is that it employs weighting with correction of the integration domain. The resulting maps of LIS can be used to determine the chemical composition, e.g., in substitutional solid solutions, such as A(x)B(1-x), A(x)B(1-x)C. The method is applied to process a high-resolution electron micrograph of a heterostructure with a submonolayer InGaAs/GaAs lattice. (C) 2001 MAIK "Nauka /Interperiodica".