Quantitative evaluation of specimen thickness, composition and strain in GaNxAs1−x at atomic resolution.
(a) Construction of Voronoi diagrams from high-resolution STEM images. (b,c) Voronoi images for the angular ranges 42–66 and 82–141 mrad. Intensity is given in fractions of I0. Comparison with simulation yields (d) nitrogen content and (e) specimen thickness for each atomic column. (f) Profiles from averaging the data in (d,e) vertically. (g) Strain profile measured from the atomic column distances in the STEM image with largest acceptance angle.