This example demonstrates nicely the potential of the Momentum Microscope: Starting with a real space image you can chose a certain region of interest (ROI). This is done by centering the ROI by means of the x-y sample stage and closing of the iris aperture (1st real zwischenbild) down to the size of the feature you like to investigate. After the instrument is switched from real space imaging to k-space image. The angular distribution seen finally is originated from the real space FOV you’ve seen before only.
Our example shown below (silver poly crystal) illustrates that two adjacent crystal domains as small as about 10µm imaged in real space mode (upper left) showing up to completely k-space images. The upper right image is taken to illustrate how the iris aperture can be used for limiting the emission area within the FOV.