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dc.contributor.authorOrava, Jirien
dc.contributor.authorHewak, Daniel Wen
dc.contributor.authorGreer, A Lindsayen
dc.date.accessioned2015-07-14T11:04:11Z
dc.date.available2015-07-14T11:04:11Z
dc.date.issued2015-07-14en
dc.identifier.citationOrava et al. Advanced Functional Materials (2015) Vol. 25, Issue 30, pp. 4851-4858. doi: 10.1002/adfm.201501607en
dc.identifier.issn1616-301X
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/248926
dc.description.abstractPhase-change random-access memory relies on the reversible crystalline-glassy phase change in chalcogenide thin films. In this application, the speed of crystallization is critical for device performance: there is a need to combine ultrafast crystallization for switching at high temperature with high resistance to crystallization for non-volatile data retention near to room temperature. In phase-change media such as nucleation-dominated Ge2Sb2Te5, these conflicting requirements are met through the highly “fragile” nature of the temperature dependence of the viscosity of the supercooled liquid. The present study explores, using ultrafast-heating calorimetry, the equivalent temperature dependence for the growth-dominated medium Ag-In-Sb-Te. The crystallization shows (unexpectedly) Arrhenius temperature dependence over a wide intermediate temperature range. Here it is shown that this is evidence for a fragile-to-strong crossover on cooling the liquid. Such a crossover has many consequences for the interpretation and control of phase-change kinetics in chalcogenide media, helping to understand the distinction between nucleation- and growth-dominated crystallization, and offering a route to designing improved device performance.
dc.description.sponsorshipJ.O., D.W.H. and A.L.G. acknowledge support from the Engineering and Physical Sciences Research Council (EPSRC, UK), D.W.H. in part through the EPSRC Centre for Innovative Manufacturing in Photonics. J.O. and A.L.G. acknowledge support from the World Premier International Research Center Initiative (WPI), MEXT, Japan. C. A. Angell, L. Battezzati, G. Dalla Fontana and M. Salinga are thanked for helpful discussions.
dc.languageEnglishen
dc.language.isoenen
dc.publisherAdvanced Functional Materials
dc.subjectphase-change memoryen
dc.subjectchalcogenide glassesen
dc.subjectcrystallizationen
dc.subjectfragile-to-strong crossoveren
dc.subjectultrafast calorimetryen
dc.titleFragile-to-Strong Crossover in Supercooled Liquid Ag-In-Sb-Te Studied by Ultrafast Calorimetryen
dc.typeArticle
dc.description.versionThis is the author accepted manuscript. The final version is available from Wiley at http://onlinelibrary.wiley.com/doi/10.1002/adfm.201501607/abstract.en
prism.endingPage4858
prism.publicationDate2015en
prism.publicationNameAdvanced Functional Materialsen
prism.startingPage4851
prism.volume25en
dc.rioxxterms.funderEPSRC
rioxxterms.versionofrecord10.1002/adfm.201501607en
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserveden
rioxxterms.licenseref.startdate2015-07-14en
dc.identifier.eissn1616-3028
rioxxterms.typeJournal Article/Reviewen
pubs.funder-project-idEPSRC (EP/M015130/1)
rioxxterms.freetoread.startdate2016-07-02


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