Quantitative chemical evaluation of dilute GaNAs using ADF STEM: Avoiding surface strain induced artifacts

A new graphical software (STEM_CELL) for analysis of HRTEM and STEM-HAADF images is here introduced in detail. The advantage of the software, beyond its graphic interface, is to put together different analysis algorithms and simulation (described in an associated article) to produce novel analysis methodologies. Different implementations and improvements to state of the art approach are reported in the image analysis, filtering, normalization, background subtraction. In particular two important methodological results are here highlighted: (i) the definition of a procedure for atomic scale quantitative analysis of HAADF images, (ii) the extension of geometric phase analysis to large regions up to potentially 1 mu m through the use of under sampled images with aliasing effects.