A study of intermixing in perovskite superlattices by simulation-supported C_s-corrected HAADF-STEM

摘要

In this paper, we present and interpret high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) images of La_(0.7)Sr_(0.3)MnO_3/SrRu0_3 superlattices. The images were taken in a probe-corrected (c-s =0) FEI microscope at 300 kV. We developed a simulation-based technique to evaluate possible intermixing at the interfaces via Z-contrast. The experimental and simulated image intensities across the interfaces are directly compared, where the gradients in the models are systematically varied. Different gradients in different sub-lattices at the interfaces can clearly be distinguished by a best fit criterion. Coloured HAADF-STEM image (V=300kV, c_s = 0) of a La_(0.7)Sr_(0.3)MnO_3/SrRuO_3 layer structure.