dc.contributor.author | Akola, J. | |
dc.contributor.author | Jones, R. O. | |
dc.contributor.author | Kalikka, Janne | |
dc.date.accessioned | 2014-12-09T21:24:51Z | |
dc.date.available | 2014-12-09T21:24:51Z | |
dc.date.issued | 2014-11 | |
dc.date.submitted | 2014-10 | |
dc.identifier.issn | 1098-0121 | |
dc.identifier.issn | 1550-235X | |
dc.identifier.uri | http://hdl.handle.net/1721.1/92241 | |
dc.description.abstract | Crystallization of amorphous Ge[subscript 2]Sb[subscript 2]Te[subscript 5] (GST) has been studied using four extensive (460 atoms, up to 4 ns) density functional/molecular dynamics simulations at 600 K. This phase change material is a rare system where crystallization can be simulated without adjustable parameters over the physical time scale, and the results could provide insight into order-disorder processes in general. Crystallization is accompanied by an increase in the number of ABAB squares (A : Ge,Sb; B : Te), percolation, and the occurrence of low-frequency localized vibration modes. A sample with a history of order crystallizes completely in 1.2 ns, but ordering in others was less complete, even after 4 ns. The amorphous starting structures without memory display phases (>1ns) with subcritical nuclei (10–50 atoms) ranging from nearly cubical blocks to stringlike configurations of ABAB squares and AB bonds extending across the cell. Percolation initiates the rapid phase of crystallization and is coupled to the directional p-type bonding in metastable GST. Cavities play a crucial role, and the final ordered structure is distorted rock salt with a face-centered cubic sublattice containing predominantly Te atoms. We comment on earlier models based on smaller and much shorter simulations. | en_US |
dc.description.sponsorship | Singapore University of Technology and Design | en_US |
dc.publisher | American Physical Society | en_US |
dc.relation.isversionof | http://dx.doi.org/10.1103/PhysRevB.90.184109 | en_US |
dc.rights | Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. | en_US |
dc.source | American Physical Society | en_US |
dc.title | Simulation of Crystallization in Ge[subscript 2]Sb[subscript 2]Te[subscript 2]: A Memory Effect in the Canonical Phase-Change Material | en_US |
dc.type | Article | en_US |
dc.identifier.citation | Kalikka, J., J. Akola, and R. O. Jones. “Simulation of Crystallization in Ge[subscript 2]Sb[subscript 2]Te[subscript 2]: A Memory Effect in the Canonical Phase-Change Material.” Physical Review B 90.18 (2014): n. pag. © 2014 American Physical Society | en_US |
dc.contributor.department | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering | en_US |
dc.contributor.mitauthor | Kalikka, Janne | en_US |
dc.relation.journal | Physical Review B | en_US |
dc.eprint.version | Final published version | en_US |
dc.type.uri | http://purl.org/eprint/type/JournalArticle | en_US |
eprint.status | http://purl.org/eprint/status/PeerReviewed | en_US |
dc.date.updated | 2014-11-26T23:00:06Z | |
dc.language.rfc3066 | en | |
dc.rights.holder | American Physical Society | |
dspace.orderedauthors | Kalikka, J.; Akola, J.; Jones, R. O. | en_US |
mit.license | PUBLISHER_POLICY | en_US |
mit.metadata.status | Complete | |