High-resolution scanning transmission electron microscope (STEM) imaging was performed using a Thermo Fisher Themis Z operated at an accelerating voltage of 300 kV. A Cs-aberration corrector ensured optimal probe coherence by correcting aberrations up to the fifth order prior to image acquisition. The monochromator facilitated a reduction in the probe beam current to approximately 1 pA (Fluscr een reading). A four-segment annular dark-field (ADF) detector collected scattered electrons within an angular range of 6-34 mrad. The illumination geometry employed a conical probe with a semi-convergence angle of 10 mrad at a camera length of 230 mm. Image reconstruction f or optimum bright-field (OBF)-STEM was achieved using in-house developed code based on methods described elsewhere . A nonlinear filter was utilized on OBF-STEM images for denoising . The lattice-averaged potential maps were obtained by crystallographic image processing using the software CRISP44 .