ANALYSIS OF THE METAL-SEMICONDUCTOR STRUCTURAL PHASE-TRANSITION IN FESI2 BY TIGHT-BINDING MOLECULAR-DYNAMICS

We show that tight-binding molecular dynamics provides a detailed desc ription of the relations between structural deformations and changes i n the electronic features during a Jahn-Teller process. In this case t he metal-semiconductor displacitive phase transition occurring in epit axial FeSi2 with film thickness can be correctly reproduced and interp reted by variable cell molecular dynamics for the bulk configuration. We show that it actually corresponds to a pattern of local Jahn-Teller distortions occurring at selected sites in different times, so that t he configurational evolution cannot be described by a global coordinat e.