ab initio; phase change materials; Molecular dynamics; aging; drift; glasses
Abstract :
[en] Aging phenomena are common to all amorphous structures, but
of special importance in phase change materials (PCM) since it
impedes the realization of multi-level memories. Different interpretations
have been proposed, but we focus here on the structural
relaxation of amorphous GeTe, chosen because it is the simplest
system that is representative of the wider class of GST alloys, lying
along the GeTe-Sb2Te3 composition line of the GeSbTe phase
diagram. We investigate the structure of amorphous GeTe using
Density Functional Theory based Molecular Dynamics, using either
the standard Generalized Gradient Approximation, or more elaborate
Van der Waals approximation. New insight is provided on the
stability of homopolar GeGe bonds and tetrahedral Ge bonding,
in relation with the resistance drift phenomenon, that is investigated
experimentally using photothermal deflection spectroscopy
experiments
Research Center/Unit :
Physique des Solides, Interfaces et Nanostructures
Disciplines :
Physics
Author, co-author :
Raty, Jean-Yves ; Université de Liège > Département de physique > Physique expérimentale des matériaux nanostructurés
Zhang, Wei
Luckas, Jennifer
Mazzarello, Riccardo
Bichara, Christophe
Wuttig, Matthias
Language :
English
Title :
Aging mechanisms in amorphous GeTe
Publication date :
18 May 2015
Event name :
2015 Glass & Optical Materials Division and Deutsche Glastechnische Gesellschaft ACerS GOMD–DGG Joint Meeting
Event organizer :
American Ceramics Society and Deutsche Glass Gesellschaft
F.R.S.-FNRS - Fonds de la Recherche Scientifique FWB - Fédération Wallonie-Bruxelles DGTRE - Région wallonne. Direction générale des Technologies, de la Recherche et de l'Énergie ULiège - Université de Liège
