physica status solidi (a)
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Editor: Stefan Hildebrandt (Editor-in-Chief), Sabine Bahrs (Deputy Editor)
Online ISSN: 1862-6319
Back Cover: Bipolar resistance switching in chalcogenide materials (Phys. Status Solidi A 10/2011)
Reversible bipolar resistance switching in Ge2Sb3Te5 films has been investigated by Pradel et al. (pp. 2303-2308) using Conductive-Atomic Force Microscopy (C-AFM). The C-AFM current images shown on the cover page clearly evidence a reversible switching from resistive to conductive states as the polarity of the bias across the sample is reversed. A primary and irreversible contraction of the film along with an increase in its conductivity occurs when a bias is applied to the as-deposited resistive film. It is related to a crystallization of the film. Further write/erase cycles induce resistance switching but no change in the contraction/expansion of the films. Such behaviour corroborates a mechanism where an amorphous Sb-rich phase would exist in between Ge2Sb2Te5 crystallites. This would create conductive paths when a bias is applied, paths that would break when the polarity is reversed.