title: Evidence for electronic gap-driven metal-semiconductor transition in phase-change materials.
abstract: Phase-change materials are functionally important materials that can be thermally interconverted between metallic (crystalline) and semiconducting (amorphous) phases on a very short time scale. Although the interconversion appears to involve a change in local atomic coordination numbers, the electronic basis for this process is still unclear. Here, we demonstrate that in a nearly vacancy-free binary GeSb system where we can drive the phase change both thermally and, as we discover, by pressure, the transformation into the amorphous phase is electronic in origin. Correlations between conductivity, total system energy, and local atomic coordination revealed by experiments and long time ab initio simulations show that the structural reorganization into the amorphous state is driven by opening of an energy gap in the electronic density of states. The electronic driving force behind the phase change has the potential to change the interconversion paradigm in this material class.
authors: Department of Applied Mathematics, University of Western Ontario, London, ON, Canada N6A5B7.
authors: Dmitry
authors: D
authors: Shakhvorostov
authors: Razvan A
authors: RA
authors: Nistor
authors: Lia
authors: L
authors: Krusin-Elbaum
authors: Glenn J
authors: GJ
authors: Martyna
authors: Dennis M
authors: DM
authors: Newns
authors: Bruce G
authors: BG
authors: Elmegreen
authors: Xiao-hu
authors: XH
authors: Liu
authors: Zak E
authors: ZE
authors: Hughes
authors: Sujata
authors: S
authors: Paul
authors: Cyril
authors: C
authors: Cabral
authors: Simone
authors: S
authors: Raoux
authors: David B
authors: DB
authors: Shrekenhamer
authors: Dimitri N
authors: DN
authors: Basov
authors: Young
authors: Y
authors: Song
authors: Martin H
authors: MH
authors: Müser