STRUCTURAL PHASE-TRANSITION DURING HETEROEPITAXIAL GROWTH OF IRON SILICIDES ON SI(111)

We report here on a novel metal-semiconductor phase transition in FeSi 2, induced by epitaxy on Si(111). The transition occurs at constant te mperature as a function of the thickness of a silicide film with const ant composition, epitaxially grown on Si(111). The phase transition co nsists in a change of the silicide structure from gamma-FeSi2, a metal lic phase with the highly symmetric fluorite structure, to beta-FeSi2, a semiconducting phase with the low symmetry orthorhombic structure.