A XAFS study of amorphous-crystalline phase transitions along the GeTe-Sb2Te3 pseudobinary tie line

P. Fons, A. Kolobov, J. Tominaga, T. Uruga

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Re-writable phase-change memory used in optical storage (e.g. DVD-RAM) is based upon amorphous-crystalline phase changes in chalcogenide alloys of which Ge-Sb-Te are a important example. Ge-Sb-Te alloys that lie along the pseudobinary tie line GeTe-Sb2Te3 are known to exhibit high speed, reversible transitions. We have used x-ray absorption to systematically study the structural changes occurring during the amorphous to crystalline transition in several representative compounds lying on this tie-line including GeTe, Ge2Sb2Te5, and GeSb2Te4. While we find that similar (distorted rocksalt) structures exists for the metastable crystalline phase for all three compounds, we find for the amorphous phases that the bonds grow shorter and stronger with the coordination for each atom type reverting towards the local coordination predicted by the 8-N rule. The amorphous structure in each case is characterized by a switch of Ge from a nearly octahedral position to a tetrahedrally coordinated position.

Original languageEnglish
Title of host publicationInternational Symposium on Optical Memory and Optical Data Storage, ISOM_ODS 2005
PublisherOptical Society of America
ISBN (Print)1557527946, 9781557527943
Publication statusPublished - 2005 Jan 1
Externally publishedYes
EventInternational Symposium on Optical Memory and Optical Data Storage, ISOM_ODS 2005 - Honolulu, HI, United States
Duration: 2005 Jul 102005 Jul 10

Publication series

NameOptics InfoBase Conference Papers
ISSN (Electronic)2162-2701

Conference

ConferenceInternational Symposium on Optical Memory and Optical Data Storage, ISOM_ODS 2005
CountryUnited States
CityHonolulu, HI
Period05/7/1005/7/10

ASJC Scopus subject areas

  • Instrumentation
  • Atomic and Molecular Physics, and Optics

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    Fons, P., Kolobov, A., Tominaga, J., & Uruga, T. (2005). A XAFS study of amorphous-crystalline phase transitions along the GeTe-Sb2Te3 pseudobinary tie line. In International Symposium on Optical Memory and Optical Data Storage, ISOM_ODS 2005 (Optics InfoBase Conference Papers). Optical Society of America.