title: Reversible shape evolution of Ge islands on Si(001).
abstract: The evolution of strained Ge/Si(001) islands during exposure to a Si flux was investigated by scanning tunneling microscopy. Dome islands display appreciable shape changes at Si coverages as low as 0.5 monolayer. With increasing coverage, they transform into [105]-faceted pyramids, and eventually into stepped mounds with steps parallel to the <110> directions. These morphological changes are induced by alloying and represent a complete reversal of those previously observed during Ge island growth. The results are interpreted with a simple model in which the equilibrium shape of an island mainly depends on its volume and composition.
authors.affiliation: INFM-Università di Pavia, Via Bassi 6, I-27100 Pavia, Italy. rastelli@solid.phys.ethz.ch
authors.forename: A
authors.initials: A
authors.lastname: Rastelli
authors.forename: M
authors.initials: M
authors.lastname: Kummer
authors.forename: H
authors.initials: H
authors.lastname: von Känel