Aging mechanisms in amorphous phase-change materials

[en] Aging is a ubiquitous phenomenon in glasses. In the case of phase-change materials, it leads to a drift in the electrical resistance, which hinders the development of ultrahigh density storage devices. Here we elucidate the aging process in amorphous GeTe, a prototypical phase-change material, by advanced numerical simulations, photothermal deflection spectroscopy and impedance spectroscopy experiments. We show that aging is accompanied by a progressive change of the local chemical order towards the crystalline one. Yet, the glass evolves towards a covalent amorphous network with increasing Peierls distortion, whose structural and electronic properties drift away from those of the resonantly bonded crystal. This behaviour sets phase-change materials apart from conventional glass-forming systems, which display the same local structure and bonding in both phases

Disciplines :

Physics

Author, co-author :

Raty, Jean-Yves ; Université de Liège > Département de physique > Physique expérimentale des matériaux nanostructurés

Zhang, wei

Luckas, Jennifer

Chen, Chao

Mazzarello, Riccardo

Bichara, Christophe

Wuttig, Matthias

Language :

English

Title :

Aging mechanisms in amorphous phase-change materials

Publication date :

24 June 2015

Journal title :

Nature Communications

eISSN :

2041-1723

Publisher :

Nature Pub.lishing Group, London, United Kingdom

Volume :

Issue :

7467

Pages :

1-8

Peer reviewed :

Peer Reviewed verified by ORBi

Tags :

CÉCI : Consortium des Équipements de Calcul Intensif
Tier-1 supercomputer

Additional URL :

http://dx.doi.org/10.1038/ncomms8467

Funders :

F.R.S.-FNRS - Fonds de la Recherche Scientifique
DGTRE - Région wallonne. Direction générale des Technologies, de la Recherche et de l'Énergie
RWTH Aachen - Rheinisch-Westfälische Technische Hochschule Aachen
ANR - Agence Nationale de la Recherche

Funding text :

We gratefully acknowledge the computational resources provided by (a) the Consortium des Equipements de Calcul Intensif, funded by the Fonds de la Recherche Scientifique de Belgique (F.R.S.-FNRS) under Grant No. 2.5020.11, (b) the Tier-1 supercomputer of the Fédération Wallonie-Bruxelles, infrastructure funded by the Walloon Region under the grant agreement n°1117545 and (c) JARA-HPC from RWTH Aachen University under project JARA0089. Support from the ARC ‘Themoterm’ grant for J.-Y.R., DFG (German Science Foundation) within the collaborative research centre SFB 917 ‘Nanoswitches’ for W.Z., R.M. and M.W., ANR (French Research Funding Agency) Grant No. ANR-11- BS08-0012 ‘TeAm’ for C.B is also acknowledged. J.L. thanks R. Carius and J. KlomfaB for the PDS measurements. The crystal structures in this paper are plotted by using the software POV-Ray.

Available on ORBi :

since 29 June 2015

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