Structure of phase change materials for data storage
2006 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 96, no 5Article in journal (Refereed) Published
Phase change materials based on chalcogenide alloys play an important role in optical and electrical memory devices. Both applications rely on the reversible phase transition of these alloys between amorphous and metastable cubic states. However, their atomic arrangements are not yet clear, which results in the unknown phase change mechanism of the utilization. Here using ab initio calculations we have determined the atomic arrangements. The results show that the metastable structure consists of special repeated units possessing rocksalt symmetry, whereas the so-called vacancy positions are highly ordered and layered and just result from the cubic symmetry. Finally, the fast and reversible phase change comes from the intrinsic similarity in the structures of the amorphous and metastable states.
Place, publisher, year, edition, pages
2006. Vol. 96, no 5
initio molecular-dynamics, ge2sb2te5 thin-films, electron-diffraction, optical memory, crystallization, transitions, microscopy, germanium, disk
IdentifiersURN: urn:nbn:se:kth:diva-15416DOI: 10.1103/PhysRevLett.96.055507ISI: 000235252200047ScopusID: 2-s2.0-33244486323OAI: oai:DiVA.org:kth-15416DiVA: diva2:333457
QC 201005252010-08-052010-08-05Bibliographically approved