Detection and quantification of small misalignments in nanometer-sized particles on oxide support systems by the analysis of plan view HREM images

摘要

The analysis of Plan View HREM images, using image processing and simulation, to retrieve information about the orientation relationships between small, nanometer-sized, particles and the crystalline support on which they are grown is illustrated. Plan view images are demonstrated to be much more sensitive than edge-on views to rotations of the particles out of perfect alignment relationships. It is also shown how double diffraction effects amplify rotations of very small amplitude. In the diffractograms experimental parameters that measure the relative position of Moire spots with respect to those of the support have been defined and proposed as a way to quantifying rotations of even only a few degrees. Equations to derive the value of the rotation angle from these experimental parameters have been developed.