Atomistic origin of doping-enhanced rapid crystallization in Ag-doped Ge-Sb-Te alloys: a joint experimental and theoretical study

We have applied extended X-ray absorption fine structure (EXAFS) analyses and ab-initio molecular dynamics (AIMD) simulations to study the atomic structure of Ag-doped (up to 42%) Ge1Sb2Te4 alloys. Analysis of the models that are consistent with the EXAFS experiment reveals that the Ge environment i...

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Bibliographic Details
Published in:arXiv.org 2013-03
Main Authors: Prasai, B, Kordesch, M E, Drabold, D A, Chen, G
Format: Article
Language:English
Subjects:
Antimony
Atomic structure
Computer simulation
Crystallization
Doping
Dynamic structural analysis
Fine structure
Molecular dynamics
Molecular structure
Silver
Tellurium
X ray absorption
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Summary:We have applied extended X-ray absorption fine structure (EXAFS) analyses and ab-initio molecular dynamics (AIMD) simulations to study the atomic structure of Ag-doped (up to 42%) Ge1Sb2Te4 alloys. Analysis of the models that are consistent with the EXAFS experiment reveals that the Ge environment is significantly modified by Ag doping whereas those of Sb and Te are barely affected (except for high Ag concentrations), and suggests that Ag prefers bonding with Te to Ge or Sb. Doping with Ag promotes the conversion of tetrahedral Ge sites to octahedral Ge sites and enhances the speed of crystallization of Ge-Sb-Te (GST) alloys as evidenced directly from the MD simulations. Our study shed light on the atomistic mechanism of rapid crystallization of GST alloys enhanced by Ag doping.
ISSN:2331-8422
DOI:10.48550/arxiv.1302.5757