Quantum size stabilization of Ge3Pt nanofilms on Ge(001)

The electronic and structural properties of a Ge-Pt alloy film on Ge(001) were studied with low-energy electron microscopy. Well above 1000 K, a bulklike eutectic film forms, followed by the emergence of an ordered Ge3Pt alloy upon solidification, which sets in at 1004 K. This eight-layers-thick Ge3Pt phase is remarkably robust as it is stabilized by quantum size effects. Further cooling results in the evolution of ultrathin Pt-induced nanowires around 650 K. The process is reversible upon temperature variation around the eutectic point. The results are considered representative of an important class of surface alloys.