Structural examination of the interface between Au catalysts and Ge(1Â 1Â 1)

We investigate the interface between Au catalysts and a Ge(1 1 1) substrate. This system is achieved by dewetting an Au layer above the Au-Ge eutectic temperature. We show by high resolution transmission electron microscopy that a large amount of Ge can be moved over a surface of Ge(1 1 1) by using assistance of eutectic Au-Ge droplets. This localization is achieved thanks to the ability of nano Au-Ge droplets to incorporate a large amount of Ge and to release it by cooling down the sample at room temperature. This makes the localization process irreversible with respect to annealing at a very high temperature. The extra Ge supplied by precipitation is in epitaxy with the Ge(1 1 1) substrate. This reflects in macroscopic I(V) measurements.