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 tr ansformations of images, various methods of noise filtration and use of spe ctral windows, and determination of local interplanar spacings (LIS) from c ross-sectional high-resolution electron micrographs. The algorithm for dete rmining the LIS consists in obtaining, by double fast Fourier transformatio n, a high-resolution image filtered by selecting an appropriate combination of reflections and using this image to find the characteristic LIS. A spec ific feature of this algorithm is that it employs weighting with correction of the integration domain. The resulting maps of LIS can be used to determ ine 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-resolu tion electron micrograph of a heterostructure with a submonolayer InGaAs/Ga As lattice. (C) 2001 MAIK "Nauka /Interperiodica".