Structure of planar defects in (Sr0.9Ca0.3)1.1CuO2 infinite-layer superconductors by quantitative high-resolution electron microscopy

Planar defects in the infinite-layer (Sr1−xCax)yCuO2 structure are believed to be responsible for superconductivity with Tc up to 110 K. In this work we present χ2 minimization results to best fit a set of through-focal HREM images of such defects. Optimized atomic positions of the defect with an error bar of about 0.1Åare determined. The experimental parameters for simulated defect images such as sample thickness and objective lens defocus are determined by χ2 fitting of the corresponding experimental HREM images of the matrix.