Epitaxial layer-by-layer growth of ultrathin metallic films is a way to control interface roughness between different materials on the atomic scale.  This is crucial, for example, for obtaining defined magnetic coupling at the interface between films of different spin structures.  In this ATM, the interested participant will deposit metal films on metallic single-crystal surfaces by thermal evaporation in ultra-high vacuum.  Layer-by-layer growth will be monitored by the intensity oscillations in medium-energy electron diffraction during deposition.  Afterwards, the films are characterized by Auger electron spectroscopy and low-energy electron diffraction, where kinematic analysis of the intensity of the specularly diffracted electrons yields the average vertical lattice spacing.