Spot-Profile-Analysis low energy electron diffraction (SPA-LEED) is a powerful tool for the analysis of crystalline surface structures. Designed for the ultimate resolution in k-space by Prof. Henzler at the University of Hannover, it is exclusively manufactured by Omicron NanoTechnology.
SPA-LEED enables precise quantitative analysis of lateral and vertical lattice constants, terrace/islands size and height distribution, ordering parameters in phase transitions and much more. The SEM mode allows for easy sample navigation and local analysis on small samples. In addition a standard LEED screen (with a reduced screen size compared to standard LEEDS) allows for alignment and easy navigation in k-space.
The heart of the SPA-LEED instrument are two electrostatic octopole deflection units which can scan the diffracted electron beam over a single electron detector with a small entrance aperture. As a result, signal to noise ratio and resolution are dramatically improved compared to conventional, screen and camera based LEED systems, as well as allowing operation at reduced sample currents. The resulting lateral resolution is given by the transfer width of the instrument of better than 1000 Angstroms. The usable dynamic range is between 1 and 8*106 counts per second.